conform to pep 3110

brutally replace all `exeption <type>, <name>:` by
`exception <type> as <name> :`

`exception <type>, <type> :` should not be present anywhere in the code
anymore, or should be present with explicit tuple as
`exception (<type>, <type>)`

IPython/config/loader.py

@@ -1,696 +1,696 b''
 """A simple configuration system.
 
 Authors
 -------
 * Brian Granger
 * Fernando Perez
 * Min RK
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import __builtin__ as builtin_mod
 import os
 import re
 import sys
 
 from IPython.external import argparse
 from IPython.utils.path import filefind, get_ipython_dir
 from IPython.utils import py3compat, text, warn
 from IPython.utils.encoding import DEFAULT_ENCODING
 
 #-----------------------------------------------------------------------------
 # Exceptions
 #-----------------------------------------------------------------------------
 
 
 class ConfigError(Exception):
     pass
 
 class ConfigLoaderError(ConfigError):
     pass
 
 class ConfigFileNotFound(ConfigError):
     pass
 
 class ArgumentError(ConfigLoaderError):
     pass
 
 #-----------------------------------------------------------------------------
 # Argparse fix
 #-----------------------------------------------------------------------------
 
 # Unfortunately argparse by default prints help messages to stderr instead of
 # stdout.  This makes it annoying to capture long help screens at the command
 # line, since one must know how to pipe stderr, which many users don't know how
 # to do.  So we override the print_help method with one that defaults to
 # stdout and use our class instead.
 
 class ArgumentParser(argparse.ArgumentParser):
     """Simple argparse subclass that prints help to stdout by default."""
 
     def print_help(self, file=None):
         if file is None:
             file = sys.stdout
         return super(ArgumentParser, self).print_help(file)
 
     print_help.__doc__ = argparse.ArgumentParser.print_help.__doc__
 
 #-----------------------------------------------------------------------------
 # Config class for holding config information
 #-----------------------------------------------------------------------------
 
 
 class Config(dict):
     """An attribute based dict that can do smart merges."""
 
     def __init__(self, *args, **kwds):
         dict.__init__(self, *args, **kwds)
         # This sets self.__dict__ = self, but it has to be done this way
         # because we are also overriding __setattr__.
         dict.__setattr__(self, '__dict__', self)
 
     def _merge(self, other):
         to_update = {}
         for k, v in other.iteritems():
             if not self.has_key(k):
                 to_update[k] = v
             else: # I have this key
                 if isinstance(v, Config):
                     # Recursively merge common sub Configs
                     self[k]._merge(v)
                 else:
                     # Plain updates for non-Configs
                     to_update[k] = v
 
         self.update(to_update)
 
     def _is_section_key(self, key):
         if key[0].upper()==key[0] and not key.startswith('_'):
             return True
         else:
             return False
 
     def __contains__(self, key):
         if self._is_section_key(key):
             return True
         else:
             return super(Config, self).__contains__(key)
     # .has_key is deprecated for dictionaries.
     has_key = __contains__
 
     def _has_section(self, key):
         if self._is_section_key(key):
             if super(Config, self).__contains__(key):
                 return True
         return False
 
     def copy(self):
         return type(self)(dict.copy(self))
 
     def __copy__(self):
         return self.copy()
 
     def __deepcopy__(self, memo):
         import copy
         return type(self)(copy.deepcopy(self.items()))
 
     def __getitem__(self, key):
         # We cannot use directly self._is_section_key, because it triggers
         # infinite recursion on top of PyPy. Instead, we manually fish the
         # bound method.
         is_section_key = self.__class__._is_section_key.__get__(self)
 
         # Because we use this for an exec namespace, we need to delegate
         # the lookup of names in __builtin__ to itself.  This means
         # that you can't have section or attribute names that are
         # builtins.
         try:
             return getattr(builtin_mod, key)
         except AttributeError:
             pass
         if is_section_key(key):
             try:
                 return dict.__getitem__(self, key)
             except KeyError:
                 c = Config()
                 dict.__setitem__(self, key, c)
                 return c
         else:
             return dict.__getitem__(self, key)
 
     def __setitem__(self, key, value):
         # Don't allow names in __builtin__ to be modified.
         if hasattr(builtin_mod, key):
             raise ConfigError('Config variable names cannot have the same name '
                               'as a Python builtin: %s' % key)
         if self._is_section_key(key):
             if not isinstance(value, Config):
                 raise ValueError('values whose keys begin with an uppercase '
                                  'char must be Config instances: %r, %r' % (key, value))
         else:
             dict.__setitem__(self, key, value)
 
     def __getattr__(self, key):
         try:
             return self.__getitem__(key)
-        except KeyError, e:
+        except KeyError as e:
             raise AttributeError(e)
 
     def __setattr__(self, key, value):
         try:
             self.__setitem__(key, value)
-        except KeyError, e:
+        except KeyError as e:
             raise AttributeError(e)
 
     def __delattr__(self, key):
         try:
             dict.__delitem__(self, key)
-        except KeyError, e:
+        except KeyError as e:
             raise AttributeError(e)
 
 
 #-----------------------------------------------------------------------------
 # Config loading classes
 #-----------------------------------------------------------------------------
 
 
 class ConfigLoader(object):
     """A object for loading configurations from just about anywhere.
 
     The resulting configuration is packaged as a :class:`Struct`.
 
     Notes
     -----
     A :class:`ConfigLoader` does one thing: load a config from a source
     (file, command line arguments) and returns the data as a :class:`Struct`.
     There are lots of things that :class:`ConfigLoader` does not do.  It does
     not implement complex logic for finding config files.  It does not handle
     default values or merge multiple configs.  These things need to be
     handled elsewhere.
     """
 
     def __init__(self):
         """A base class for config loaders.
 
         Examples
         --------
 
         >>> cl = ConfigLoader()
         >>> config = cl.load_config()
         >>> config
         {}
         """
         self.clear()
 
     def clear(self):
         self.config = Config()
 
     def load_config(self):
         """Load a config from somewhere, return a :class:`Config` instance.
 
         Usually, this will cause self.config to be set and then returned.
         However, in most cases, :meth:`ConfigLoader.clear` should be called
         to erase any previous state.
         """
         self.clear()
         return self.config
 
 
 class FileConfigLoader(ConfigLoader):
     """A base class for file based configurations.
 
     As we add more file based config loaders, the common logic should go
     here.
     """
     pass
 
 
 class PyFileConfigLoader(FileConfigLoader):
     """A config loader for pure python files.
 
     This calls execfile on a plain python file and looks for attributes
     that are all caps.  These attribute are added to the config Struct.
     """
 
     def __init__(self, filename, path=None):
         """Build a config loader for a filename and path.
 
         Parameters
         ----------
         filename : str
             The file name of the config file.
         path : str, list, tuple
             The path to search for the config file on, or a sequence of
             paths to try in order.
         """
         super(PyFileConfigLoader, self).__init__()
         self.filename = filename
         self.path = path
         self.full_filename = ''
         self.data = None
 
     def load_config(self):
         """Load the config from a file and return it as a Struct."""
         self.clear()
         try:
             self._find_file()
         except IOError as e:
             raise ConfigFileNotFound(str(e))
         self._read_file_as_dict()
         self._convert_to_config()
         return self.config
 
     def _find_file(self):
         """Try to find the file by searching the paths."""
         self.full_filename = filefind(self.filename, self.path)
 
     def _read_file_as_dict(self):
         """Load the config file into self.config, with recursive loading."""
         # This closure is made available in the namespace that is used
         # to exec the config file.  It allows users to call
         # load_subconfig('myconfig.py') to load config files recursively.
         # It needs to be a closure because it has references to self.path
         # and self.config.  The sub-config is loaded with the same path
         # as the parent, but it uses an empty config which is then merged
         # with the parents.
 
         # If a profile is specified, the config file will be loaded
         # from that profile
 
         def load_subconfig(fname, profile=None):
             # import here to prevent circular imports
             from IPython.core.profiledir import ProfileDir, ProfileDirError
             if profile is not None:
                 try:
                     profile_dir = ProfileDir.find_profile_dir_by_name(
                             get_ipython_dir(),
                             profile,
                     )
                 except ProfileDirError:
                     return
                 path = profile_dir.location
             else:
                 path = self.path
             loader = PyFileConfigLoader(fname, path)
             try:
                 sub_config = loader.load_config()
             except ConfigFileNotFound:
                 # Pass silently if the sub config is not there. This happens
                 # when a user s using a profile, but not the default config.
                 pass
             else:
                 self.config._merge(sub_config)
 
         # Again, this needs to be a closure and should be used in config
         # files to get the config being loaded.
         def get_config():
             return self.config
 
         namespace = dict(load_subconfig=load_subconfig, get_config=get_config)
         fs_encoding = sys.getfilesystemencoding() or 'ascii'
         conf_filename = self.full_filename.encode(fs_encoding)
         py3compat.execfile(conf_filename, namespace)
 
     def _convert_to_config(self):
         if self.data is None:
             ConfigLoaderError('self.data does not exist')
 
 
 class CommandLineConfigLoader(ConfigLoader):
     """A config loader for command line arguments.
 
     As we add more command line based loaders, the common logic should go
     here.
     """
 
     def _exec_config_str(self, lhs, rhs):
         """execute self.config.<lhs> = <rhs>
         
         * expands ~ with expanduser
         * tries to assign with raw eval, otherwise assigns with just the string,
           allowing `--C.a=foobar` and `--C.a="foobar"` to be equivalent.  *Not*
           equivalent are `--C.a=4` and `--C.a='4'`.
         """
         rhs = os.path.expanduser(rhs)
         try:
             # Try to see if regular Python syntax will work. This
             # won't handle strings as the quote marks are removed
             # by the system shell.
             value = eval(rhs)
         except (NameError, SyntaxError):
             # This case happens if the rhs is a string.
             value = rhs
 
         exec u'self.config.%s = value' % lhs
 
     def _load_flag(self, cfg):
         """update self.config from a flag, which can be a dict or Config"""
         if isinstance(cfg, (dict, Config)):
             # don't clobber whole config sections, update
             # each section from config:
             for sec,c in cfg.iteritems():
                 self.config[sec].update(c)
         else:
             raise TypeError("Invalid flag: %r" % cfg)
 
 # raw --identifier=value pattern
 # but *also* accept '-' as wordsep, for aliases
 # accepts:  --foo=a
 #           --Class.trait=value
 #           --alias-name=value
 # rejects:  -foo=value
 #           --foo
 #           --Class.trait
 kv_pattern = re.compile(r'\-\-[A-Za-z][\w\-]*(\.[\w\-]+)*\=.*')
 
 # just flags, no assignments, with two *or one* leading '-'
 # accepts:  --foo
 #           -foo-bar-again
 # rejects:  --anything=anything
 #           --two.word
 
 flag_pattern = re.compile(r'\-\-?\w+[\-\w]*$')
 
 class KeyValueConfigLoader(CommandLineConfigLoader):
     """A config loader that loads key value pairs from the command line.
 
     This allows command line options to be gives in the following form::
 
         ipython --profile="foo" --InteractiveShell.autocall=False
     """
 
     def __init__(self, argv=None, aliases=None, flags=None):
         """Create a key value pair config loader.
 
         Parameters
         ----------
         argv : list
             A list that has the form of sys.argv[1:] which has unicode
             elements of the form u"key=value". If this is None (default),
             then sys.argv[1:] will be used.
         aliases : dict
             A dict of aliases for configurable traits.
             Keys are the short aliases, Values are the resolved trait.
             Of the form: `{'alias' : 'Configurable.trait'}`
         flags : dict
             A dict of flags, keyed by str name. Vaues can be Config objects,
             dicts, or "key=value" strings.  If Config or dict, when the flag
             is triggered, The flag is loaded as `self.config.update(m)`.
 
         Returns
         -------
         config : Config
             The resulting Config object.
 
         Examples
         --------
 
             >>> from IPython.config.loader import KeyValueConfigLoader
             >>> cl = KeyValueConfigLoader()
             >>> d = cl.load_config(["--A.name='brian'","--B.number=0"])
             >>> sorted(d.items())
             [('A', {'name': 'brian'}), ('B', {'number': 0})]
         """
         self.clear()
         if argv is None:
             argv = sys.argv[1:]
         self.argv = argv
         self.aliases = aliases or {}
         self.flags = flags or {}
 
 
     def clear(self):
         super(KeyValueConfigLoader, self).clear()
         self.extra_args = []
 
 
     def _decode_argv(self, argv, enc=None):
         """decode argv if bytes, using stin.encoding, falling back on default enc"""
         uargv = []
         if enc is None:
             enc = DEFAULT_ENCODING
         for arg in argv:
             if not isinstance(arg, unicode):
                 # only decode if not already decoded
                 arg = arg.decode(enc)
             uargv.append(arg)
         return uargv
 
 
     def load_config(self, argv=None, aliases=None, flags=None):
         """Parse the configuration and generate the Config object.
 
         After loading, any arguments that are not key-value or
         flags will be stored in self.extra_args - a list of
         unparsed command-line arguments.  This is used for
         arguments such as input files or subcommands.
 
         Parameters
         ----------
         argv : list, optional
             A list that has the form of sys.argv[1:] which has unicode
             elements of the form u"key=value". If this is None (default),
             then self.argv will be used.
         aliases : dict
             A dict of aliases for configurable traits.
             Keys are the short aliases, Values are the resolved trait.
             Of the form: `{'alias' : 'Configurable.trait'}`
         flags : dict
             A dict of flags, keyed by str name. Values can be Config objects
             or dicts.  When the flag is triggered, The config is loaded as
             `self.config.update(cfg)`.
         """
         from IPython.config.configurable import Configurable
 
         self.clear()
         if argv is None:
             argv = self.argv
         if aliases is None:
             aliases = self.aliases
         if flags is None:
             flags = self.flags
 
         # ensure argv is a list of unicode strings:
         uargv = self._decode_argv(argv)
         for idx,raw in enumerate(uargv):
             # strip leading '-'
             item = raw.lstrip('-')
 
             if raw == '--':
                 # don't parse arguments after '--'
                 # this is useful for relaying arguments to scripts, e.g.
                 # ipython -i foo.py --pylab=qt -- args after '--' go-to-foo.py
                 self.extra_args.extend(uargv[idx+1:])
                 break
 
             if kv_pattern.match(raw):
                 lhs,rhs = item.split('=',1)
                 # Substitute longnames for aliases.
                 if lhs in aliases:
                     lhs = aliases[lhs]
                 if '.' not in lhs:
                     # probably a mistyped alias, but not technically illegal
                     warn.warn("Unrecognized alias: '%s', it will probably have no effect."%lhs)
                 try:
                     self._exec_config_str(lhs, rhs)
                 except Exception:
                     raise ArgumentError("Invalid argument: '%s'" % raw)
 
             elif flag_pattern.match(raw):
                 if item in flags:
                     cfg,help = flags[item]
                     self._load_flag(cfg)
                 else:
                     raise ArgumentError("Unrecognized flag: '%s'"%raw)
             elif raw.startswith('-'):
                 kv = '--'+item
                 if kv_pattern.match(kv):
                     raise ArgumentError("Invalid argument: '%s', did you mean '%s'?"%(raw, kv))
                 else:
                     raise ArgumentError("Invalid argument: '%s'"%raw)
             else:
                 # keep all args that aren't valid in a list,
                 # in case our parent knows what to do with them.
                 self.extra_args.append(item)
         return self.config
 
 class ArgParseConfigLoader(CommandLineConfigLoader):
     """A loader that uses the argparse module to load from the command line."""
 
     def __init__(self, argv=None, aliases=None, flags=None, *parser_args, **parser_kw):
         """Create a config loader for use with argparse.
 
         Parameters
         ----------
 
         argv : optional, list
           If given, used to read command-line arguments from, otherwise
           sys.argv[1:] is used.
 
         parser_args : tuple
           A tuple of positional arguments that will be passed to the
           constructor of :class:`argparse.ArgumentParser`.
 
         parser_kw : dict
           A tuple of keyword arguments that will be passed to the
           constructor of :class:`argparse.ArgumentParser`.
 
         Returns
         -------
         config : Config
             The resulting Config object.
         """
         super(CommandLineConfigLoader, self).__init__()
         self.clear()
         if argv is None:
             argv = sys.argv[1:]
         self.argv = argv
         self.aliases = aliases or {}
         self.flags = flags or {}
 
         self.parser_args = parser_args
         self.version = parser_kw.pop("version", None)
         kwargs = dict(argument_default=argparse.SUPPRESS)
         kwargs.update(parser_kw)
         self.parser_kw = kwargs
 
     def load_config(self, argv=None, aliases=None, flags=None):
         """Parse command line arguments and return as a Config object.
 
         Parameters
         ----------
 
         args : optional, list
           If given, a list with the structure of sys.argv[1:] to parse
           arguments from. If not given, the instance's self.argv attribute
           (given at construction time) is used."""
         self.clear()
         if argv is None:
             argv = self.argv
         if aliases is None:
             aliases = self.aliases
         if flags is None:
             flags = self.flags
         self._create_parser(aliases, flags)
         self._parse_args(argv)
         self._convert_to_config()
         return self.config
 
     def get_extra_args(self):
         if hasattr(self, 'extra_args'):
             return self.extra_args
         else:
             return []
 
     def _create_parser(self, aliases=None, flags=None):
         self.parser = ArgumentParser(*self.parser_args, **self.parser_kw)
         self._add_arguments(aliases, flags)
 
     def _add_arguments(self, aliases=None, flags=None):
         raise NotImplementedError("subclasses must implement _add_arguments")
 
     def _parse_args(self, args):
         """self.parser->self.parsed_data"""
         # decode sys.argv to support unicode command-line options
         enc = DEFAULT_ENCODING
         uargs = [py3compat.cast_unicode(a, enc) for a in args]
         self.parsed_data, self.extra_args = self.parser.parse_known_args(uargs)
 
     def _convert_to_config(self):
         """self.parsed_data->self.config"""
         for k, v in vars(self.parsed_data).iteritems():
             exec "self.config.%s = v"%k in locals(), globals()
 
 class KVArgParseConfigLoader(ArgParseConfigLoader):
     """A config loader that loads aliases and flags with argparse,
     but will use KVLoader for the rest.  This allows better parsing
     of common args, such as `ipython -c 'print 5'`, but still gets
     arbitrary config with `ipython --InteractiveShell.use_readline=False`"""
 
     def _add_arguments(self, aliases=None, flags=None):
         self.alias_flags = {}
         # print aliases, flags
         if aliases is None:
             aliases = self.aliases
         if flags is None:
             flags = self.flags
         paa = self.parser.add_argument
         for key,value in aliases.iteritems():
             if key in flags:
                 # flags
                 nargs = '?'
             else:
                 nargs = None
             if len(key) is 1:
                 paa('-'+key, '--'+key, type=unicode, dest=value, nargs=nargs)
             else:
                 paa('--'+key, type=unicode, dest=value, nargs=nargs)
         for key, (value, help) in flags.iteritems():
             if key in self.aliases:
                 #
                 self.alias_flags[self.aliases[key]] = value
                 continue
             if len(key) is 1:
                 paa('-'+key, '--'+key, action='append_const', dest='_flags', const=value)
             else:
                 paa('--'+key, action='append_const', dest='_flags', const=value)
 
     def _convert_to_config(self):
         """self.parsed_data->self.config, parse unrecognized extra args via KVLoader."""
         # remove subconfigs list from namespace before transforming the Namespace
         if '_flags' in self.parsed_data:
             subcs = self.parsed_data._flags
             del self.parsed_data._flags
         else:
             subcs = []
 
         for k, v in vars(self.parsed_data).iteritems():
             if v is None:
                 # it was a flag that shares the name of an alias
                 subcs.append(self.alias_flags[k])
             else:
                 # eval the KV assignment
                 self._exec_config_str(k, v)
 
         for subc in subcs:
             self._load_flag(subc)
 
         if self.extra_args:
             sub_parser = KeyValueConfigLoader()
             sub_parser.load_config(self.extra_args)
             self.config._merge(sub_parser.config)
             self.extra_args = sub_parser.extra_args
 
 
 def load_pyconfig_files(config_files, path):
     """Load multiple Python config files, merging each of them in turn.
 
     Parameters
     ==========
     config_files : list of str
         List of config files names to load and merge into the config.
     path : unicode
         The full path to the location of the config files.
     """
     config = Config()
     for cf in config_files:
         loader = PyFileConfigLoader(cf, path=path)
         try:
             next_config = loader.load_config()
         except ConfigFileNotFound:
             pass
         except:
             raise
         else:
             config._merge(next_config)
     return config

IPython/core/alias.py

@@ -1,263 +1,263 b''
 # encoding: utf-8
 """
 System command aliases.
 
 Authors:
 
 * Fernando Perez
 * Brian Granger
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import __builtin__
 import keyword
 import os
 import re
 import sys
 
 from IPython.config.configurable import Configurable
 from IPython.core.splitinput import split_user_input
 
 from IPython.utils.traitlets import List, Instance
 from IPython.utils.autoattr import auto_attr
 from IPython.utils.warn import warn, error
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 # This is used as the pattern for calls to split_user_input.
 shell_line_split = re.compile(r'^(\s*)()(\S+)(.*$)')
 
 def default_aliases():
     """Return list of shell aliases to auto-define.
     """
     # Note: the aliases defined here should be safe to use on a kernel
     # regardless of what frontend it is attached to.  Frontends that use a
     # kernel in-process can define additional aliases that will only work in
     # their case.  For example, things like 'less' or 'clear' that manipulate
     # the terminal should NOT be declared here, as they will only work if the
     # kernel is running inside a true terminal, and not over the network.
 
     if os.name == 'posix':
         default_aliases = [('mkdir', 'mkdir'), ('rmdir', 'rmdir'),
                            ('mv', 'mv -i'), ('rm', 'rm -i'), ('cp', 'cp -i'),
                            ('cat', 'cat'),
                            ]
         # Useful set of ls aliases.  The GNU and BSD options are a little
         # different, so we make aliases that provide as similar as possible
         # behavior in ipython, by passing the right flags for each platform
         if sys.platform.startswith('linux'):
             ls_aliases = [('ls', 'ls -F --color'),
                           # long ls
                           ('ll', 'ls -F -o --color'),
                           # ls normal files only
                           ('lf', 'ls -F -o --color %l | grep ^-'),
                           # ls symbolic links
                           ('lk', 'ls -F -o --color %l | grep ^l'),
                           # directories or links to directories,
                           ('ldir', 'ls -F -o --color %l | grep /$'),
                           # things which are executable
                           ('lx', 'ls -F -o --color %l | grep ^-..x'),
                           ]
         else:
             # BSD, OSX, etc.
             ls_aliases = [('ls', 'ls -F'),
                           # long ls
                           ('ll', 'ls -F -l'),
                           # ls normal files only
                           ('lf', 'ls -F -l %l | grep ^-'),
                           # ls symbolic links
                           ('lk', 'ls -F -l %l | grep ^l'),
                           # directories or links to directories,
                           ('ldir', 'ls -F -l %l | grep /$'),
                           # things which are executable
                           ('lx', 'ls -F -l %l | grep ^-..x'),
                           ]
         default_aliases = default_aliases + ls_aliases
     elif os.name in ['nt', 'dos']:
         default_aliases = [('ls', 'dir /on'),
                            ('ddir', 'dir /ad /on'), ('ldir', 'dir /ad /on'),
                            ('mkdir', 'mkdir'), ('rmdir', 'rmdir'),
                            ('echo', 'echo'), ('ren', 'ren'), ('copy', 'copy'),
                            ]
     else:
         default_aliases = []
 
     return default_aliases
 
 
 class AliasError(Exception):
     pass
 
 
 class InvalidAliasError(AliasError):
     pass
 
 #-----------------------------------------------------------------------------
 # Main AliasManager class
 #-----------------------------------------------------------------------------
 
 class AliasManager(Configurable):
 
     default_aliases = List(default_aliases(), config=True)
     user_aliases = List(default_value=[], config=True)
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
 
     def __init__(self, shell=None, config=None):
         super(AliasManager, self).__init__(shell=shell, config=config)
         self.alias_table = {}
         self.exclude_aliases()
         self.init_aliases()
 
     def __contains__(self, name):
         return name in self.alias_table
 
     @property
     def aliases(self):
         return [(item[0], item[1][1]) for item in self.alias_table.iteritems()]
 
     def exclude_aliases(self):
         # set of things NOT to alias (keywords, builtins and some magics)
         no_alias = set(['cd','popd','pushd','dhist','alias','unalias'])
         no_alias.update(set(keyword.kwlist))
         no_alias.update(set(__builtin__.__dict__.keys()))
         self.no_alias = no_alias
 
     def init_aliases(self):
         # Load default aliases
         for name, cmd in self.default_aliases:
             self.soft_define_alias(name, cmd)
 
         # Load user aliases
         for name, cmd in self.user_aliases:
             self.soft_define_alias(name, cmd)
 
     def clear_aliases(self):
         self.alias_table.clear()
 
     def soft_define_alias(self, name, cmd):
         """Define an alias, but don't raise on an AliasError."""
         try:
             self.define_alias(name, cmd)
-        except AliasError, e:
+        except AliasError as e:
             error("Invalid alias: %s" % e)
 
     def define_alias(self, name, cmd):
         """Define a new alias after validating it.
 
         This will raise an :exc:`AliasError` if there are validation
         problems.
         """
         nargs = self.validate_alias(name, cmd)
         self.alias_table[name] = (nargs, cmd)
 
     def undefine_alias(self, name):
         if self.alias_table.has_key(name):
             del self.alias_table[name]
 
     def validate_alias(self, name, cmd):
         """Validate an alias and return the its number of arguments."""
         if name in self.no_alias:
             raise InvalidAliasError("The name %s can't be aliased "
                                     "because it is a keyword or builtin." % name)
         if not (isinstance(cmd, basestring)):
             raise InvalidAliasError("An alias command must be a string, "
                                     "got: %r" % cmd)
         nargs = cmd.count('%s')
         if nargs>0 and cmd.find('%l')>=0:
             raise InvalidAliasError('The %s and %l specifiers are mutually '
                                     'exclusive in alias definitions.')
         return nargs
 
     def call_alias(self, alias, rest=''):
         """Call an alias given its name and the rest of the line."""
         cmd = self.transform_alias(alias, rest)
         try:
             self.shell.system(cmd)
         except:
             self.shell.showtraceback()
 
     def transform_alias(self, alias,rest=''):
         """Transform alias to system command string."""
         nargs, cmd = self.alias_table[alias]
 
         if ' ' in cmd and os.path.isfile(cmd):
             cmd = '"%s"' % cmd
 
         # Expand the %l special to be the user's input line
         if cmd.find('%l') >= 0:
             cmd = cmd.replace('%l', rest)
             rest = ''
         if nargs==0:
             # Simple, argument-less aliases
             cmd = '%s %s' % (cmd, rest)
         else:
             # Handle aliases with positional arguments
             args = rest.split(None, nargs)
             if len(args) < nargs:
                 raise AliasError('Alias <%s> requires %s arguments, %s given.' %
                       (alias, nargs, len(args)))
             cmd = '%s %s' % (cmd % tuple(args[:nargs]),' '.join(args[nargs:]))
         return cmd
 
     def expand_alias(self, line):
         """ Expand an alias in the command line
 
         Returns the provided command line, possibly with the first word
         (command) translated according to alias expansion rules.
 
         [ipython]|16> _ip.expand_aliases("np myfile.txt")
                  <16> 'q:/opt/np/notepad++.exe myfile.txt'
         """
 
         pre,_,fn,rest = split_user_input(line)
         res = pre + self.expand_aliases(fn, rest)
         return res
 
     def expand_aliases(self, fn, rest):
         """Expand multiple levels of aliases:
 
         if:
 
         alias foo bar /tmp
         alias baz foo
 
         then:
 
         baz huhhahhei -> bar /tmp huhhahhei
         """
         line = fn + " " + rest
 
         done = set()
         while 1:
             pre,_,fn,rest = split_user_input(line, shell_line_split)
             if fn in self.alias_table:
                 if fn in done:
                     warn("Cyclic alias definition, repeated '%s'" % fn)
                     return ""
                 done.add(fn)
 
                 l2 = self.transform_alias(fn, rest)
                 if l2 == line:
                     break
                 # ls -> ls -F should not recurse forever
                 if l2.split(None,1)[0] == line.split(None,1)[0]:
                     line = l2
                     break
                 line=l2
             else:
                 break
 
         return line

IPython/core/interactiveshell.py

@@ -1,3009 +1,3009 b''
 # -*- coding: utf-8 -*-
 """Main IPython class."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2001 Janko Hauser <[e-mail]>
 #  Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from __future__ import with_statement
 from __future__ import absolute_import
 
 import __builtin__ as builtin_mod
 import __future__
 import abc
 import ast
 import atexit
 import os
 import re
 import runpy
 import sys
 import tempfile
 import types
 
 # We need to use nested to support python 2.6, once we move to >=2.7, we can
 # use the with keyword's new builtin support for nested managers
 try:
     from contextlib import nested
 except:
     from IPython.utils.nested_context import nested
 
 from IPython.config.configurable import SingletonConfigurable
 from IPython.core import debugger, oinspect
 from IPython.core import history as ipcorehist
 from IPython.core import magic
 from IPython.core import page
 from IPython.core import prefilter
 from IPython.core import shadowns
 from IPython.core import ultratb
 from IPython.core.alias import AliasManager, AliasError
 from IPython.core.autocall import ExitAutocall
 from IPython.core.builtin_trap import BuiltinTrap
 from IPython.core.compilerop import CachingCompiler
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.displayhook import DisplayHook
 from IPython.core.displaypub import DisplayPublisher
 from IPython.core.error import UsageError
 from IPython.core.extensions import ExtensionManager
 from IPython.core.fakemodule import FakeModule, init_fakemod_dict
 from IPython.core.formatters import DisplayFormatter
 from IPython.core.history import HistoryManager
 from IPython.core.inputsplitter import IPythonInputSplitter, ESC_MAGIC, ESC_MAGIC2
 from IPython.core.logger import Logger
 from IPython.core.macro import Macro
 from IPython.core.payload import PayloadManager
 from IPython.core.plugin import PluginManager
 from IPython.core.prefilter import PrefilterManager
 from IPython.core.profiledir import ProfileDir
 from IPython.core.pylabtools import pylab_activate
 from IPython.core.prompts import PromptManager
 from IPython.utils import PyColorize
 from IPython.utils import io
 from IPython.utils import py3compat
 from IPython.utils import openpy
 from IPython.utils.doctestreload import doctest_reload
 from IPython.utils.io import ask_yes_no
 from IPython.utils.ipstruct import Struct
 from IPython.utils.path import get_home_dir, get_ipython_dir, get_py_filename, unquote_filename
 from IPython.utils.pickleshare import PickleShareDB
 from IPython.utils.process import system, getoutput
 from IPython.utils.strdispatch import StrDispatch
 from IPython.utils.syspathcontext import prepended_to_syspath
 from IPython.utils.text import (format_screen, LSString, SList,
                                 DollarFormatter)
 from IPython.utils.traitlets import (Integer, CBool, CaselessStrEnum, Enum,
                                      List, Unicode, Instance, Type)
 from IPython.utils.warn import warn, error
 import IPython.core.hooks
 
 # FIXME: do this in a function to avoid circular dependencies
 # A better solution is to remove IPython.parallel.error,
 # and place those classes in IPython.core.error.
 
 class RemoteError(Exception):
     pass
 
 def _import_remote_error():
     global RemoteError
     try:
         from IPython.parallel.error import RemoteError
     except:
         pass
 
 _import_remote_error()
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 # compiled regexps for autoindent management
 dedent_re = re.compile(r'^\s+raise|^\s+return|^\s+pass')
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 def softspace(file, newvalue):
     """Copied from code.py, to remove the dependency"""
 
     oldvalue = 0
     try:
         oldvalue = file.softspace
     except AttributeError:
         pass
     try:
         file.softspace = newvalue
     except (AttributeError, TypeError):
         # "attribute-less object" or "read-only attributes"
         pass
     return oldvalue
 
 
 def no_op(*a, **kw): pass
 
 class NoOpContext(object):
     def __enter__(self): pass
     def __exit__(self, type, value, traceback): pass
 no_op_context = NoOpContext()
 
 class SpaceInInput(Exception): pass
 
 class Bunch: pass
 
 
 def get_default_colors():
     if sys.platform=='darwin':
         return "LightBG"
     elif os.name=='nt':
         return 'Linux'
     else:
         return 'Linux'
 
 
 class SeparateUnicode(Unicode):
     """A Unicode subclass to validate separate_in, separate_out, etc.
 
     This is a Unicode based trait that converts '0'->'' and '\\n'->'\n'.
     """
 
     def validate(self, obj, value):
         if value == '0': value = ''
         value = value.replace('\\n','\n')
         return super(SeparateUnicode, self).validate(obj, value)
 
 
 class ReadlineNoRecord(object):
     """Context manager to execute some code, then reload readline history
     so that interactive input to the code doesn't appear when pressing up."""
     def __init__(self, shell):
         self.shell = shell
         self._nested_level = 0
 
     def __enter__(self):
         if self._nested_level == 0:
             try:
                 self.orig_length = self.current_length()
                 self.readline_tail = self.get_readline_tail()
             except (AttributeError, IndexError):   # Can fail with pyreadline
                 self.orig_length, self.readline_tail = 999999, []
         self._nested_level += 1
 
     def __exit__(self, type, value, traceback):
         self._nested_level -= 1
         if self._nested_level == 0:
             # Try clipping the end if it's got longer
             try:
                 e = self.current_length() - self.orig_length
                 if e > 0:
                     for _ in range(e):
                         self.shell.readline.remove_history_item(self.orig_length)
 
                 # If it still doesn't match, just reload readline history.
                 if self.current_length() != self.orig_length \
                     or self.get_readline_tail() != self.readline_tail:
                     self.shell.refill_readline_hist()
             except (AttributeError, IndexError):
                 pass
         # Returning False will cause exceptions to propagate
         return False
 
     def current_length(self):
         return self.shell.readline.get_current_history_length()
 
     def get_readline_tail(self, n=10):
         """Get the last n items in readline history."""
         end = self.shell.readline.get_current_history_length() + 1
         start = max(end-n, 1)
         ghi = self.shell.readline.get_history_item
         return [ghi(x) for x in range(start, end)]
 
 #-----------------------------------------------------------------------------
 # Main IPython class
 #-----------------------------------------------------------------------------
 
 class InteractiveShell(SingletonConfigurable):
     """An enhanced, interactive shell for Python."""
 
     _instance = None
 
     autocall = Enum((0,1,2), default_value=0, config=True, help=
         """
         Make IPython automatically call any callable object even if you didn't
         type explicit parentheses. For example, 'str 43' becomes 'str(43)'
         automatically. The value can be '0' to disable the feature, '1' for
         'smart' autocall, where it is not applied if there are no more
         arguments on the line, and '2' for 'full' autocall, where all callable
         objects are automatically called (even if no arguments are present).
         """
     )
     # TODO: remove all autoindent logic and put into frontends.
     # We can't do this yet because even runlines uses the autoindent.
     autoindent = CBool(True, config=True, help=
         """
         Autoindent IPython code entered interactively.
         """
     )
     automagic = CBool(True, config=True, help=
         """
         Enable magic commands to be called without the leading %.
         """
     )
     cache_size = Integer(1000, config=True, help=
         """
         Set the size of the output cache.  The default is 1000, you can
         change it permanently in your config file.  Setting it to 0 completely
         disables the caching system, and the minimum value accepted is 20 (if
         you provide a value less than 20, it is reset to 0 and a warning is
         issued).  This limit is defined because otherwise you'll spend more
         time re-flushing a too small cache than working
         """
     )
     color_info = CBool(True, config=True, help=
         """
         Use colors for displaying information about objects. Because this
         information is passed through a pager (like 'less'), and some pagers
         get confused with color codes, this capability can be turned off.
         """
     )
     colors = CaselessStrEnum(('NoColor','LightBG','Linux'),
                              default_value=get_default_colors(), config=True,
         help="Set the color scheme (NoColor, Linux, or LightBG)."
     )
     colors_force = CBool(False, help=
         """
         Force use of ANSI color codes, regardless of OS and readline
         availability.
         """
         # FIXME: This is essentially a hack to allow ZMQShell to show colors
         # without readline on Win32. When the ZMQ formatting system is
         # refactored, this should be removed.
     )
     debug = CBool(False, config=True)
     deep_reload = CBool(False, config=True, help=
         """
         Enable deep (recursive) reloading by default. IPython can use the
         deep_reload module which reloads changes in modules recursively (it
         replaces the reload() function, so you don't need to change anything to
         use it). deep_reload() forces a full reload of modules whose code may
         have changed, which the default reload() function does not.  When
         deep_reload is off, IPython will use the normal reload(), but
         deep_reload will still be available as dreload().
         """
     )
     disable_failing_post_execute = CBool(False, config=True,
         help="Don't call post-execute functions that have failed in the past."
     )
     display_formatter = Instance(DisplayFormatter)
     displayhook_class = Type(DisplayHook)
     display_pub_class = Type(DisplayPublisher)
 
     exit_now = CBool(False)
     exiter = Instance(ExitAutocall)
     def _exiter_default(self):
         return ExitAutocall(self)
     # Monotonically increasing execution counter
     execution_count = Integer(1)
     filename = Unicode("<ipython console>")
     ipython_dir= Unicode('', config=True) # Set to get_ipython_dir() in __init__
 
     # Input splitter, to split entire cells of input into either individual
     # interactive statements or whole blocks.
     input_splitter = Instance('IPython.core.inputsplitter.IPythonInputSplitter',
                               (), {})
     logstart = CBool(False, config=True, help=
         """
         Start logging to the default log file.
         """
     )
     logfile = Unicode('', config=True, help=
         """
         The name of the logfile to use.
         """
     )
     logappend = Unicode('', config=True, help=
         """
         Start logging to the given file in append mode.
         """
     )
     object_info_string_level = Enum((0,1,2), default_value=0,
                                     config=True)
     pdb = CBool(False, config=True, help=
         """
         Automatically call the pdb debugger after every exception.
         """
     )
     multiline_history = CBool(sys.platform != 'win32', config=True,
         help="Save multi-line entries as one entry in readline history"
     )
 
     # deprecated prompt traits:
     
     prompt_in1 = Unicode('In [\\#]: ', config=True,
         help="Deprecated, use PromptManager.in_template")
     prompt_in2 = Unicode('   .\\D.: ', config=True,
         help="Deprecated, use PromptManager.in2_template")
     prompt_out = Unicode('Out[\\#]: ', config=True,
         help="Deprecated, use PromptManager.out_template")
     prompts_pad_left = CBool(True, config=True,
         help="Deprecated, use PromptManager.justify")
     
     def _prompt_trait_changed(self, name, old, new):
         table = {
             'prompt_in1' : 'in_template',
             'prompt_in2' : 'in2_template',
             'prompt_out' : 'out_template',
             'prompts_pad_left' : 'justify',
         }
         warn("InteractiveShell.{name} is deprecated, use PromptManager.{newname}\n".format(
                 name=name, newname=table[name])
         )
         # protect against weird cases where self.config may not exist:
         if self.config is not None:
             # propagate to corresponding PromptManager trait
             setattr(self.config.PromptManager, table[name], new)
     
     _prompt_in1_changed = _prompt_trait_changed
     _prompt_in2_changed = _prompt_trait_changed
     _prompt_out_changed = _prompt_trait_changed
     _prompt_pad_left_changed = _prompt_trait_changed
     
     show_rewritten_input = CBool(True, config=True,
         help="Show rewritten input, e.g. for autocall."
     )
     
     quiet = CBool(False, config=True)
 
     history_length = Integer(10000, config=True)
 
     # The readline stuff will eventually be moved to the terminal subclass
     # but for now, we can't do that as readline is welded in everywhere.
     readline_use = CBool(True, config=True)
     readline_remove_delims = Unicode('-/~', config=True)
     # don't use \M- bindings by default, because they
     # conflict with 8-bit encodings. See gh-58,gh-88
     readline_parse_and_bind = List([
             'tab: complete',
             '"\C-l": clear-screen',
             'set show-all-if-ambiguous on',
             '"\C-o": tab-insert',
             '"\C-r": reverse-search-history',
             '"\C-s": forward-search-history',
             '"\C-p": history-search-backward',
             '"\C-n": history-search-forward',
             '"\e[A": history-search-backward',
             '"\e[B": history-search-forward',
             '"\C-k": kill-line',
             '"\C-u": unix-line-discard',
         ], allow_none=False, config=True)
 
     ast_node_interactivity = Enum(['all', 'last', 'last_expr', 'none'],
                                   default_value='last_expr', config=True, 
                                   help="""
         'all', 'last', 'last_expr' or 'none', specifying which nodes should be
         run interactively (displaying output from expressions).""")
 
     # TODO: this part of prompt management should be moved to the frontends.
     # Use custom TraitTypes that convert '0'->'' and '\\n'->'\n'
     separate_in = SeparateUnicode('\n', config=True)
     separate_out = SeparateUnicode('', config=True)
     separate_out2 = SeparateUnicode('', config=True)
     wildcards_case_sensitive = CBool(True, config=True)
     xmode = CaselessStrEnum(('Context','Plain', 'Verbose'),
                             default_value='Context', config=True)
 
     # Subcomponents of InteractiveShell
     alias_manager = Instance('IPython.core.alias.AliasManager')
     prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
     builtin_trap = Instance('IPython.core.builtin_trap.BuiltinTrap')
     display_trap = Instance('IPython.core.display_trap.DisplayTrap')
     extension_manager = Instance('IPython.core.extensions.ExtensionManager')
     plugin_manager = Instance('IPython.core.plugin.PluginManager')
     payload_manager = Instance('IPython.core.payload.PayloadManager')
     history_manager = Instance('IPython.core.history.HistoryManager')
     magics_manager = Instance('IPython.core.magic.MagicsManager')
 
     profile_dir = Instance('IPython.core.application.ProfileDir')
     @property
     def profile(self):
         if self.profile_dir is not None:
             name = os.path.basename(self.profile_dir.location)
             return name.replace('profile_','')
 
 
     # Private interface
     _post_execute = Instance(dict)
 
     def __init__(self, config=None, ipython_dir=None, profile_dir=None,
                  user_module=None, user_ns=None,
                  custom_exceptions=((), None)):
 
         # This is where traits with a config_key argument are updated
         # from the values on config.
         super(InteractiveShell, self).__init__(config=config)
         self.configurables = [self]
 
         # These are relatively independent and stateless
         self.init_ipython_dir(ipython_dir)
         self.init_profile_dir(profile_dir)
         self.init_instance_attrs()
         self.init_environment()
         
         # Check if we're in a virtualenv, and set up sys.path.
         self.init_virtualenv()
 
         # Create namespaces (user_ns, user_global_ns, etc.)
         self.init_create_namespaces(user_module, user_ns)
         # This has to be done after init_create_namespaces because it uses
         # something in self.user_ns, but before init_sys_modules, which
         # is the first thing to modify sys.
         # TODO: When we override sys.stdout and sys.stderr before this class
         # is created, we are saving the overridden ones here. Not sure if this
         # is what we want to do.
         self.save_sys_module_state()
         self.init_sys_modules()
 
         # While we're trying to have each part of the code directly access what
         # it needs without keeping redundant references to objects, we have too
         # much legacy code that expects ip.db to exist.
         self.db = PickleShareDB(os.path.join(self.profile_dir.location, 'db'))
 
         self.init_history()
         self.init_encoding()
         self.init_prefilter()
 
         self.init_syntax_highlighting()
         self.init_hooks()
         self.init_pushd_popd_magic()
         # self.init_traceback_handlers use to be here, but we moved it below
         # because it and init_io have to come after init_readline.
         self.init_user_ns()
         self.init_logger()
         self.init_alias()
         self.init_builtins()
 
         # pre_config_initialization
 
         # The next section should contain everything that was in ipmaker.
         self.init_logstart()
 
         # The following was in post_config_initialization
         self.init_inspector()
         # init_readline() must come before init_io(), because init_io uses
         # readline related things.
         self.init_readline()
         # We save this here in case user code replaces raw_input, but it needs
         # to be after init_readline(), because PyPy's readline works by replacing
         # raw_input.
         if py3compat.PY3:
             self.raw_input_original = input
         else:
             self.raw_input_original = raw_input
         # init_completer must come after init_readline, because it needs to
         # know whether readline is present or not system-wide to configure the
         # completers, since the completion machinery can now operate
         # independently of readline (e.g. over the network)
         self.init_completer()
         # TODO: init_io() needs to happen before init_traceback handlers
         # because the traceback handlers hardcode the stdout/stderr streams.
         # This logic in in debugger.Pdb and should eventually be changed.
         self.init_io()
         self.init_traceback_handlers(custom_exceptions)
         self.init_prompts()
         self.init_display_formatter()
         self.init_display_pub()
         self.init_displayhook()
         self.init_reload_doctest()
         self.init_magics()
         self.init_pdb()
         self.init_extension_manager()
         self.init_plugin_manager()
         self.init_payload()
         self.hooks.late_startup_hook()
         atexit.register(self.atexit_operations)
 
     def get_ipython(self):
         """Return the currently running IPython instance."""
         return self
 
     #-------------------------------------------------------------------------
     # Trait changed handlers
     #-------------------------------------------------------------------------
 
     def _ipython_dir_changed(self, name, new):
         if not os.path.isdir(new):
             os.makedirs(new, mode = 0777)
 
     def set_autoindent(self,value=None):
         """Set the autoindent flag, checking for readline support.
 
         If called with no arguments, it acts as a toggle."""
 
         if value != 0 and not self.has_readline:
             if os.name == 'posix':
                 warn("The auto-indent feature requires the readline library")
             self.autoindent = 0
             return
         if value is None:
             self.autoindent = not self.autoindent
         else:
             self.autoindent = value
 
     #-------------------------------------------------------------------------
     # init_* methods called by __init__
     #-------------------------------------------------------------------------
 
     def init_ipython_dir(self, ipython_dir):
         if ipython_dir is not None:
             self.ipython_dir = ipython_dir
             return
 
         self.ipython_dir = get_ipython_dir()
 
     def init_profile_dir(self, profile_dir):
         if profile_dir is not None:
             self.profile_dir = profile_dir
             return
         self.profile_dir =\
             ProfileDir.create_profile_dir_by_name(self.ipython_dir, 'default')
 
     def init_instance_attrs(self):
         self.more = False
 
         # command compiler
         self.compile = CachingCompiler()
 
         # Make an empty namespace, which extension writers can rely on both
         # existing and NEVER being used by ipython itself.  This gives them a
         # convenient location for storing additional information and state
         # their extensions may require, without fear of collisions with other
         # ipython names that may develop later.
         self.meta = Struct()
 
         # Temporary files used for various purposes.  Deleted at exit.
         self.tempfiles = []
 
         # Keep track of readline usage (later set by init_readline)
         self.has_readline = False
 
         # keep track of where we started running (mainly for crash post-mortem)
         # This is not being used anywhere currently.
         self.starting_dir = os.getcwdu()
 
         # Indentation management
         self.indent_current_nsp = 0
 
         # Dict to track post-execution functions that have been registered
         self._post_execute = {}
 
     def init_environment(self):
         """Any changes we need to make to the user's environment."""
         pass
 
     def init_encoding(self):
         # Get system encoding at startup time.  Certain terminals (like Emacs
         # under Win32 have it set to None, and we need to have a known valid
         # encoding to use in the raw_input() method
         try:
             self.stdin_encoding = sys.stdin.encoding or 'ascii'
         except AttributeError:
             self.stdin_encoding = 'ascii'
 
     def init_syntax_highlighting(self):
         # Python source parser/formatter for syntax highlighting
         pyformat = PyColorize.Parser().format
         self.pycolorize = lambda src: pyformat(src,'str',self.colors)
 
     def init_pushd_popd_magic(self):
         # for pushd/popd management
         self.home_dir = get_home_dir()
 
         self.dir_stack = []
 
     def init_logger(self):
         self.logger = Logger(self.home_dir, logfname='ipython_log.py',
                              logmode='rotate')
 
     def init_logstart(self):
         """Initialize logging in case it was requested at the command line.
         """
         if self.logappend:
             self.magic('logstart %s append' % self.logappend)
         elif self.logfile:
             self.magic('logstart %' % self.logfile)
         elif self.logstart:
             self.magic('logstart')
 
     def init_builtins(self):
         # A single, static flag that we set to True.  Its presence indicates
         # that an IPython shell has been created, and we make no attempts at
         # removing on exit or representing the existence of more than one
         # IPython at a time.
         builtin_mod.__dict__['__IPYTHON__'] = True
 
         # In 0.11 we introduced '__IPYTHON__active' as an integer we'd try to
         # manage on enter/exit, but with all our shells it's virtually
         # impossible to get all the cases right.  We're leaving the name in for
         # those who adapted their codes to check for this flag, but will
         # eventually remove it after a few more releases.
         builtin_mod.__dict__['__IPYTHON__active'] = \
                                           'Deprecated, check for __IPYTHON__'
 
         self.builtin_trap = BuiltinTrap(shell=self)
 
     def init_inspector(self):
         # Object inspector
         self.inspector = oinspect.Inspector(oinspect.InspectColors,
                                             PyColorize.ANSICodeColors,
                                             'NoColor',
                                             self.object_info_string_level)
 
     def init_io(self):
         # This will just use sys.stdout and sys.stderr. If you want to
         # override sys.stdout and sys.stderr themselves, you need to do that
         # *before* instantiating this class, because io holds onto
         # references to the underlying streams.
         if sys.platform == 'win32' and self.has_readline:
             io.stdout = io.stderr = io.IOStream(self.readline._outputfile)
         else:
             io.stdout = io.IOStream(sys.stdout)
             io.stderr = io.IOStream(sys.stderr)
 
     def init_prompts(self):
         self.prompt_manager = PromptManager(shell=self, config=self.config)
         self.configurables.append(self.prompt_manager)
         # Set system prompts, so that scripts can decide if they are running
         # interactively.
         sys.ps1 = 'In : '
         sys.ps2 = '...: '
         sys.ps3 = 'Out: '
 
     def init_display_formatter(self):
         self.display_formatter = DisplayFormatter(config=self.config)
         self.configurables.append(self.display_formatter)
 
     def init_display_pub(self):
         self.display_pub = self.display_pub_class(config=self.config)
         self.configurables.append(self.display_pub)
 
     def init_displayhook(self):
         # Initialize displayhook, set in/out prompts and printing system
         self.displayhook = self.displayhook_class(
             config=self.config,
             shell=self,
             cache_size=self.cache_size,
         )
         self.configurables.append(self.displayhook)
         # This is a context manager that installs/revmoes the displayhook at
         # the appropriate time.
         self.display_trap = DisplayTrap(hook=self.displayhook)
 
     def init_reload_doctest(self):
         # Do a proper resetting of doctest, including the necessary displayhook
         # monkeypatching
         try:
             doctest_reload()
         except ImportError:
             warn("doctest module does not exist.")
     
     def init_virtualenv(self):
         """Add a virtualenv to sys.path so the user can import modules from it.
         This isn't perfect: it doesn't use the Python interpreter with which the
         virtualenv was built, and it ignores the --no-site-packages option. A
         warning will appear suggesting the user installs IPython in the
         virtualenv, but for many cases, it probably works well enough.
         
         Adapted from code snippets online.
         
         http://blog.ufsoft.org/2009/1/29/ipython-and-virtualenv
         """
         if 'VIRTUAL_ENV' not in os.environ:
             # Not in a virtualenv
             return
         
         if sys.executable.startswith(os.environ['VIRTUAL_ENV']):
             # Running properly in the virtualenv, don't need to do anything
             return
         
         warn("Attempting to work in a virtualenv. If you encounter problems, please "
              "install IPython inside the virtualenv.\n")
         if sys.platform == "win32":
             virtual_env = os.path.join(os.environ['VIRTUAL_ENV'], 'Lib', 'site-packages') 
         else:
             virtual_env = os.path.join(os.environ['VIRTUAL_ENV'], 'lib',
                        'python%d.%d' % sys.version_info[:2], 'site-packages')
         
         import site
         sys.path.insert(0, virtual_env)
         site.addsitedir(virtual_env)
 
     #-------------------------------------------------------------------------
     # Things related to injections into the sys module
     #-------------------------------------------------------------------------
 
     def save_sys_module_state(self):
         """Save the state of hooks in the sys module.
 
         This has to be called after self.user_module is created.
         """
         self._orig_sys_module_state = {}
         self._orig_sys_module_state['stdin'] = sys.stdin
         self._orig_sys_module_state['stdout'] = sys.stdout
         self._orig_sys_module_state['stderr'] = sys.stderr
         self._orig_sys_module_state['excepthook'] = sys.excepthook
         self._orig_sys_modules_main_name = self.user_module.__name__
         self._orig_sys_modules_main_mod = sys.modules.get(self.user_module.__name__)
 
     def restore_sys_module_state(self):
         """Restore the state of the sys module."""
         try:
             for k, v in self._orig_sys_module_state.iteritems():
                 setattr(sys, k, v)
         except AttributeError:
             pass
         # Reset what what done in self.init_sys_modules
         if self._orig_sys_modules_main_mod is not None:
             sys.modules[self._orig_sys_modules_main_name] = self._orig_sys_modules_main_mod
 
     #-------------------------------------------------------------------------
     # Things related to hooks
     #-------------------------------------------------------------------------
 
     def init_hooks(self):
         # hooks holds pointers used for user-side customizations
         self.hooks = Struct()
 
         self.strdispatchers = {}
 
         # Set all default hooks, defined in the IPython.hooks module.
         hooks = IPython.core.hooks
         for hook_name in hooks.__all__:
             # default hooks have priority 100, i.e. low; user hooks should have
             # 0-100 priority
             self.set_hook(hook_name,getattr(hooks,hook_name), 100)
 
     def set_hook(self,name,hook, priority = 50, str_key = None, re_key = None):
         """set_hook(name,hook) -> sets an internal IPython hook.
 
         IPython exposes some of its internal API as user-modifiable hooks.  By
         adding your function to one of these hooks, you can modify IPython's
         behavior to call at runtime your own routines."""
 
         # At some point in the future, this should validate the hook before it
         # accepts it.  Probably at least check that the hook takes the number
         # of args it's supposed to.
 
         f = types.MethodType(hook,self)
 
         # check if the hook is for strdispatcher first
         if str_key is not None:
             sdp = self.strdispatchers.get(name, StrDispatch())
             sdp.add_s(str_key, f, priority )
             self.strdispatchers[name] = sdp
             return
         if re_key is not None:
             sdp = self.strdispatchers.get(name, StrDispatch())
             sdp.add_re(re.compile(re_key), f, priority )
             self.strdispatchers[name] = sdp
             return
 
         dp = getattr(self.hooks, name, None)
         if name not in IPython.core.hooks.__all__:
             print "Warning! Hook '%s' is not one of %s" % \
                   (name, IPython.core.hooks.__all__ )
         if not dp:
             dp = IPython.core.hooks.CommandChainDispatcher()
 
         try:
             dp.add(f,priority)
         except AttributeError:
             # it was not commandchain, plain old func - replace
             dp = f
 
         setattr(self.hooks,name, dp)
 
     def register_post_execute(self, func):
         """Register a function for calling after code execution.
         """
         if not callable(func):
             raise ValueError('argument %s must be callable' % func)
         self._post_execute[func] = True
     
     #-------------------------------------------------------------------------
     # Things related to the "main" module
     #-------------------------------------------------------------------------
 
     def new_main_mod(self,ns=None):
         """Return a new 'main' module object for user code execution.
         """
         main_mod = self._user_main_module
         init_fakemod_dict(main_mod,ns)
         return main_mod
 
     def cache_main_mod(self,ns,fname):
         """Cache a main module's namespace.
 
         When scripts are executed via %run, we must keep a reference to the
         namespace of their __main__ module (a FakeModule instance) around so
         that Python doesn't clear it, rendering objects defined therein
         useless.
 
         This method keeps said reference in a private dict, keyed by the
         absolute path of the module object (which corresponds to the script
         path).  This way, for multiple executions of the same script we only
         keep one copy of the namespace (the last one), thus preventing memory
         leaks from old references while allowing the objects from the last
         execution to be accessible.
 
         Note: we can not allow the actual FakeModule instances to be deleted,
         because of how Python tears down modules (it hard-sets all their
         references to None without regard for reference counts).  This method
         must therefore make a *copy* of the given namespace, to allow the
         original module's __dict__ to be cleared and reused.
 
 
         Parameters
         ----------
           ns : a namespace (a dict, typically)
 
           fname : str
             Filename associated with the namespace.
 
         Examples
         --------
 
         In [10]: import IPython
 
         In [11]: _ip.cache_main_mod(IPython.__dict__,IPython.__file__)
 
         In [12]: IPython.__file__ in _ip._main_ns_cache
         Out[12]: True
         """
         self._main_ns_cache[os.path.abspath(fname)] = ns.copy()
 
     def clear_main_mod_cache(self):
         """Clear the cache of main modules.
 
         Mainly for use by utilities like %reset.
 
         Examples
         --------
 
         In [15]: import IPython
 
         In [16]: _ip.cache_main_mod(IPython.__dict__,IPython.__file__)
 
         In [17]: len(_ip._main_ns_cache) > 0
         Out[17]: True
 
         In [18]: _ip.clear_main_mod_cache()
 
         In [19]: len(_ip._main_ns_cache) == 0
         Out[19]: True
         """
         self._main_ns_cache.clear()
 
     #-------------------------------------------------------------------------
     # Things related to debugging
     #-------------------------------------------------------------------------
 
     def init_pdb(self):
         # Set calling of pdb on exceptions
         # self.call_pdb is a property
         self.call_pdb = self.pdb
 
     def _get_call_pdb(self):
         return self._call_pdb
 
     def _set_call_pdb(self,val):
 
         if val not in (0,1,False,True):
             raise ValueError,'new call_pdb value must be boolean'
 
         # store value in instance
         self._call_pdb = val
 
         # notify the actual exception handlers
         self.InteractiveTB.call_pdb = val
 
     call_pdb = property(_get_call_pdb,_set_call_pdb,None,
                         'Control auto-activation of pdb at exceptions')
 
     def debugger(self,force=False):
         """Call the pydb/pdb debugger.
 
         Keywords:
 
           - force(False): by default, this routine checks the instance call_pdb
           flag and does not actually invoke the debugger if the flag is false.
           The 'force' option forces the debugger to activate even if the flag
           is false.
         """
 
         if not (force or self.call_pdb):
             return
 
         if not hasattr(sys,'last_traceback'):
             error('No traceback has been produced, nothing to debug.')
             return
 
         # use pydb if available
         if debugger.has_pydb:
             from pydb import pm
         else:
             # fallback to our internal debugger
             pm = lambda : self.InteractiveTB.debugger(force=True)
 
         with self.readline_no_record:
             pm()
 
     #-------------------------------------------------------------------------
     # Things related to IPython's various namespaces
     #-------------------------------------------------------------------------
     default_user_namespaces = True
 
     def init_create_namespaces(self, user_module=None, user_ns=None):
         # Create the namespace where the user will operate.  user_ns is
         # normally the only one used, and it is passed to the exec calls as
         # the locals argument.  But we do carry a user_global_ns namespace
         # given as the exec 'globals' argument,  This is useful in embedding
         # situations where the ipython shell opens in a context where the
         # distinction between locals and globals is meaningful.  For
         # non-embedded contexts, it is just the same object as the user_ns dict.
 
         # FIXME. For some strange reason, __builtins__ is showing up at user
         # level as a dict instead of a module. This is a manual fix, but I
         # should really track down where the problem is coming from. Alex
         # Schmolck reported this problem first.
 
         # A useful post by Alex Martelli on this topic:
         # Re: inconsistent value from __builtins__
         # Von: Alex Martelli <[e-mail]>
         # Datum: Freitag 01 Oktober 2004 04:45:34 nachmittags/abends
         # Gruppen: comp.lang.python
 
         # Michael Hohn <[e-mail]> wrote:
         # > >>> print type(builtin_check.get_global_binding('__builtins__'))
         # > <type 'dict'>
         # > >>> print type(__builtins__)
         # > <type 'module'>
         # > Is this difference in return value intentional?
 
         # Well, it's documented that '__builtins__' can be either a dictionary
         # or a module, and it's been that way for a long time. Whether it's
         # intentional (or sensible), I don't know. In any case, the idea is
         # that if you need to access the built-in namespace directly, you
         # should start with "import __builtin__" (note, no 's') which will
         # definitely give you a module. Yeah, it's somewhat confusing:-(.
 
         # These routines return a properly built module and dict as needed by
         # the rest of the code, and can also be used by extension writers to
         # generate properly initialized namespaces.
         if (user_ns is not None) or (user_module is not None):
             self.default_user_namespaces = False
         self.user_module, self.user_ns = self.prepare_user_module(user_module, user_ns)
 
         # A record of hidden variables we have added to the user namespace, so
         # we can list later only variables defined in actual interactive use.
         self.user_ns_hidden = set()
 
         # Now that FakeModule produces a real module, we've run into a nasty
         # problem: after script execution (via %run), the module where the user
         # code ran is deleted.  Now that this object is a true module (needed
         # so docetst and other tools work correctly), the Python module
         # teardown mechanism runs over it, and sets to None every variable
         # present in that module.  Top-level references to objects from the
         # script survive, because the user_ns is updated with them.  However,
         # calling functions defined in the script that use other things from
         # the script will fail, because the function's closure had references
         # to the original objects, which are now all None.  So we must protect
         # these modules from deletion by keeping a cache.
         #
         # To avoid keeping stale modules around (we only need the one from the
         # last run), we use a dict keyed with the full path to the script, so
         # only the last version of the module is held in the cache.  Note,
         # however, that we must cache the module *namespace contents* (their
         # __dict__).  Because if we try to cache the actual modules, old ones
         # (uncached) could be destroyed while still holding references (such as
         # those held by GUI objects that tend to be long-lived)>
         #
         # The %reset command will flush this cache.  See the cache_main_mod()
         # and clear_main_mod_cache() methods for details on use.
 
         # This is the cache used for 'main' namespaces
         self._main_ns_cache = {}
         # And this is the single instance of FakeModule whose __dict__ we keep
         # copying and clearing for reuse on each %run
         self._user_main_module = FakeModule()
 
         # A table holding all the namespaces IPython deals with, so that
         # introspection facilities can search easily.
         self.ns_table = {'user_global':self.user_module.__dict__,
                          'user_local':self.user_ns,
                          'builtin':builtin_mod.__dict__
                          }
     
     @property
     def user_global_ns(self):
         return self.user_module.__dict__
 
     def prepare_user_module(self, user_module=None, user_ns=None):
         """Prepare the module and namespace in which user code will be run.
         
         When IPython is started normally, both parameters are None: a new module
         is created automatically, and its __dict__ used as the namespace.
         
         If only user_module is provided, its __dict__ is used as the namespace.
         If only user_ns is provided, a dummy module is created, and user_ns
         becomes the global namespace. If both are provided (as they may be
         when embedding), user_ns is the local namespace, and user_module
         provides the global namespace.
 
         Parameters
         ----------
         user_module : module, optional
             The current user module in which IPython is being run. If None,
             a clean module will be created.
         user_ns : dict, optional
             A namespace in which to run interactive commands.
 
         Returns
         -------
         A tuple of user_module and user_ns, each properly initialised.
         """
         if user_module is None and user_ns is not None:
             user_ns.setdefault("__name__", "__main__")
             class DummyMod(object):
                 "A dummy module used for IPython's interactive namespace."
                 pass
             user_module = DummyMod()
             user_module.__dict__ = user_ns
             
         if user_module is None:
             user_module = types.ModuleType("__main__",
                 doc="Automatically created module for IPython interactive environment")
         
         # We must ensure that __builtin__ (without the final 's') is always
         # available and pointing to the __builtin__ *module*.  For more details:
         # http://mail.python.org/pipermail/python-dev/2001-April/014068.html
         user_module.__dict__.setdefault('__builtin__', builtin_mod)
         user_module.__dict__.setdefault('__builtins__', builtin_mod)
         
         if user_ns is None:
             user_ns = user_module.__dict__
 
         return user_module, user_ns
 
     def init_sys_modules(self):
         # We need to insert into sys.modules something that looks like a
         # module but which accesses the IPython namespace, for shelve and
         # pickle to work interactively. Normally they rely on getting
         # everything out of __main__, but for embedding purposes each IPython
         # instance has its own private namespace, so we can't go shoving
         # everything into __main__.
 
         # note, however, that we should only do this for non-embedded
         # ipythons, which really mimic the __main__.__dict__ with their own
         # namespace.  Embedded instances, on the other hand, should not do
         # this because they need to manage the user local/global namespaces
         # only, but they live within a 'normal' __main__ (meaning, they
         # shouldn't overtake the execution environment of the script they're
         # embedded in).
 
         # This is overridden in the InteractiveShellEmbed subclass to a no-op.
         main_name = self.user_module.__name__
         sys.modules[main_name] = self.user_module
 
     def init_user_ns(self):
         """Initialize all user-visible namespaces to their minimum defaults.
 
         Certain history lists are also initialized here, as they effectively
         act as user namespaces.
 
         Notes
         -----
         All data structures here are only filled in, they are NOT reset by this
         method.  If they were not empty before, data will simply be added to
         therm.
         """
         # This function works in two parts: first we put a few things in
         # user_ns, and we sync that contents into user_ns_hidden so that these
         # initial variables aren't shown by %who.  After the sync, we add the
         # rest of what we *do* want the user to see with %who even on a new
         # session (probably nothing, so theye really only see their own stuff)
 
         # The user dict must *always* have a __builtin__ reference to the
         # Python standard __builtin__ namespace,  which must be imported.
         # This is so that certain operations in prompt evaluation can be
         # reliably executed with builtins.  Note that we can NOT use
         # __builtins__ (note the 's'),  because that can either be a dict or a
         # module, and can even mutate at runtime, depending on the context
         # (Python makes no guarantees on it).  In contrast, __builtin__ is
         # always a module object, though it must be explicitly imported.
 
         # For more details:
         # http://mail.python.org/pipermail/python-dev/2001-April/014068.html
         ns = dict()
         
         # Put 'help' in the user namespace
         try:
             from site import _Helper
             ns['help'] = _Helper()
         except ImportError:
             warn('help() not available - check site.py')
 
         # make global variables for user access to the histories
         ns['_ih'] = self.history_manager.input_hist_parsed
         ns['_oh'] = self.history_manager.output_hist
         ns['_dh'] = self.history_manager.dir_hist
 
         ns['_sh'] = shadowns
 
         # user aliases to input and output histories.  These shouldn't show up
         # in %who, as they can have very large reprs.
         ns['In']  = self.history_manager.input_hist_parsed
         ns['Out'] = self.history_manager.output_hist
 
         # Store myself as the public api!!!
         ns['get_ipython'] = self.get_ipython
         
         ns['exit'] = self.exiter
         ns['quit'] = self.exiter
 
         # Sync what we've added so far to user_ns_hidden so these aren't seen
         # by %who
         self.user_ns_hidden.update(ns)
 
         # Anything put into ns now would show up in %who.  Think twice before
         # putting anything here, as we really want %who to show the user their
         # stuff, not our variables.
 
         # Finally, update the real user's namespace
         self.user_ns.update(ns)
     
     @property
     def all_ns_refs(self):
         """Get a list of references to all the namespace dictionaries in which
         IPython might store a user-created object.
         
         Note that this does not include the displayhook, which also caches
         objects from the output."""
         return [self.user_ns, self.user_global_ns,
                 self._user_main_module.__dict__] + self._main_ns_cache.values()
 
     def reset(self, new_session=True):
         """Clear all internal namespaces, and attempt to release references to
         user objects.
 
         If new_session is True, a new history session will be opened.
         """
         # Clear histories
         self.history_manager.reset(new_session)
         # Reset counter used to index all histories
         if new_session:
             self.execution_count = 1
 
         # Flush cached output items
         if self.displayhook.do_full_cache:
             self.displayhook.flush()
 
         # The main execution namespaces must be cleared very carefully,
         # skipping the deletion of the builtin-related keys, because doing so
         # would cause errors in many object's __del__ methods.
         if self.user_ns is not self.user_global_ns:
             self.user_ns.clear()
         ns = self.user_global_ns
         drop_keys = set(ns.keys())
         drop_keys.discard('__builtin__')
         drop_keys.discard('__builtins__')
         drop_keys.discard('__name__')
         for k in drop_keys:
             del ns[k]
         
         self.user_ns_hidden.clear()
         
         # Restore the user namespaces to minimal usability
         self.init_user_ns()
 
         # Restore the default and user aliases
         self.alias_manager.clear_aliases()
         self.alias_manager.init_aliases()
 
         # Flush the private list of module references kept for script
         # execution protection
         self.clear_main_mod_cache()
 
         # Clear out the namespace from the last %run
         self.new_main_mod()
 
     def del_var(self, varname, by_name=False):
         """Delete a variable from the various namespaces, so that, as
         far as possible, we're not keeping any hidden references to it.
 
         Parameters
         ----------
         varname : str
             The name of the variable to delete.
         by_name : bool
             If True, delete variables with the given name in each
             namespace. If False (default), find the variable in the user
             namespace, and delete references to it.
         """
         if varname in ('__builtin__', '__builtins__'):
             raise ValueError("Refusing to delete %s" % varname)
 
         ns_refs = self.all_ns_refs
         
         if by_name:                    # Delete by name
             for ns in ns_refs:
                 try:
                     del ns[varname]
                 except KeyError:
                     pass
         else:                         # Delete by object
             try:
                 obj = self.user_ns[varname]
             except KeyError:
                 raise NameError("name '%s' is not defined" % varname)
             # Also check in output history
             ns_refs.append(self.history_manager.output_hist)
             for ns in ns_refs:
                 to_delete = [n for n, o in ns.iteritems() if o is obj]
                 for name in to_delete:
                     del ns[name]
 
             # displayhook keeps extra references, but not in a dictionary
             for name in ('_', '__', '___'):
                 if getattr(self.displayhook, name) is obj:
                     setattr(self.displayhook, name, None)
 
     def reset_selective(self, regex=None):
         """Clear selective variables from internal namespaces based on a
         specified regular expression.
 
         Parameters
         ----------
         regex : string or compiled pattern, optional
             A regular expression pattern that will be used in searching
             variable names in the users namespaces.
         """
         if regex is not None:
             try:
                 m = re.compile(regex)
             except TypeError:
                 raise TypeError('regex must be a string or compiled pattern')
             # Search for keys in each namespace that match the given regex
             # If a match is found, delete the key/value pair.
             for ns in self.all_ns_refs:
                 for var in ns:
                     if m.search(var):
                         del ns[var]
 
     def push(self, variables, interactive=True):
         """Inject a group of variables into the IPython user namespace.
 
         Parameters
         ----------
         variables : dict, str or list/tuple of str
             The variables to inject into the user's namespace.  If a dict, a
             simple update is done.  If a str, the string is assumed to have
             variable names separated by spaces.  A list/tuple of str can also
             be used to give the variable names.  If just the variable names are
             give (list/tuple/str) then the variable values looked up in the
             callers frame.
         interactive : bool
             If True (default), the variables will be listed with the ``who``
             magic.
         """
         vdict = None
 
         # We need a dict of name/value pairs to do namespace updates.
         if isinstance(variables, dict):
             vdict = variables
         elif isinstance(variables, (basestring, list, tuple)):
             if isinstance(variables, basestring):
                 vlist = variables.split()
             else:
                 vlist = variables
             vdict = {}
             cf = sys._getframe(1)
             for name in vlist:
                 try:
                     vdict[name] = eval(name, cf.f_globals, cf.f_locals)
                 except:
                     print ('Could not get variable %s from %s' %
                            (name,cf.f_code.co_name))
         else:
             raise ValueError('variables must be a dict/str/list/tuple')
 
         # Propagate variables to user namespace
         self.user_ns.update(vdict)
 
         # And configure interactive visibility
         user_ns_hidden = self.user_ns_hidden
         if interactive:
             user_ns_hidden.difference_update(vdict)
         else:
             user_ns_hidden.update(vdict)
     
     def drop_by_id(self, variables):
         """Remove a dict of variables from the user namespace, if they are the
         same as the values in the dictionary.
         
         This is intended for use by extensions: variables that they've added can
         be taken back out if they are unloaded, without removing any that the
         user has overwritten.
         
         Parameters
         ----------
         variables : dict
           A dictionary mapping object names (as strings) to the objects.
         """
         for name, obj in variables.iteritems():
             if name in self.user_ns and self.user_ns[name] is obj:
                 del self.user_ns[name]
                 self.user_ns_hidden.discard(name)
 
     #-------------------------------------------------------------------------
     # Things related to object introspection
     #-------------------------------------------------------------------------
 
     def _ofind(self, oname, namespaces=None):
         """Find an object in the available namespaces.
 
         self._ofind(oname) -> dict with keys: found,obj,ospace,ismagic
 
         Has special code to detect magic functions.
         """
         oname = oname.strip()
         #print '1- oname: <%r>' % oname  # dbg
         if not oname.startswith(ESC_MAGIC) and \
             not oname.startswith(ESC_MAGIC2) and \
             not py3compat.isidentifier(oname, dotted=True):
             return dict(found=False)
 
         alias_ns = None
         if namespaces is None:
             # Namespaces to search in:
             # Put them in a list. The order is important so that we
             # find things in the same order that Python finds them.
             namespaces = [ ('Interactive', self.user_ns),
                            ('Interactive (global)', self.user_global_ns),
                            ('Python builtin', builtin_mod.__dict__),
                            ('Alias', self.alias_manager.alias_table),
                            ]
             alias_ns = self.alias_manager.alias_table
 
         # initialize results to 'null'
         found = False; obj = None;  ospace = None;  ds = None;
         ismagic = False; isalias = False; parent = None
 
         # We need to special-case 'print', which as of python2.6 registers as a
         # function but should only be treated as one if print_function was
         # loaded with a future import.  In this case, just bail.
         if (oname == 'print' and not py3compat.PY3 and not \
             (self.compile.compiler_flags & __future__.CO_FUTURE_PRINT_FUNCTION)):
             return {'found':found, 'obj':obj, 'namespace':ospace,
                     'ismagic':ismagic, 'isalias':isalias, 'parent':parent}
 
         # Look for the given name by splitting it in parts.  If the head is
         # found, then we look for all the remaining parts as members, and only
         # declare success if we can find them all.
         oname_parts = oname.split('.')
         oname_head, oname_rest = oname_parts[0],oname_parts[1:]
         for nsname,ns in namespaces:
             try:
                 obj = ns[oname_head]
             except KeyError:
                 continue
             else:
                 #print 'oname_rest:', oname_rest  # dbg
                 for part in oname_rest:
                     try:
                         parent = obj
                         obj = getattr(obj,part)
                     except:
                         # Blanket except b/c some badly implemented objects
                         # allow __getattr__ to raise exceptions other than
                         # AttributeError, which then crashes IPython.
                         break
                 else:
                     # If we finish the for loop (no break), we got all members
                     found = True
                     ospace = nsname
                     if ns == alias_ns:
                         isalias = True
                     break  # namespace loop
 
         # Try to see if it's magic
         if not found:
             obj = None
             if oname.startswith(ESC_MAGIC2):
                 oname = oname.lstrip(ESC_MAGIC2)
                 obj = self.find_cell_magic(oname)
             elif oname.startswith(ESC_MAGIC):
                 oname = oname.lstrip(ESC_MAGIC)
                 obj = self.find_line_magic(oname)
             else:
                 # search without prefix, so run? will find %run?
                 obj = self.find_line_magic(oname)
                 if obj is None:
                     obj = self.find_cell_magic(oname)
             if obj is not None:
                 found = True
                 ospace = 'IPython internal'
                 ismagic = True
 
         # Last try: special-case some literals like '', [], {}, etc:
         if not found and oname_head in ["''",'""','[]','{}','()']:
             obj = eval(oname_head)
             found = True
             ospace = 'Interactive'
 
         return {'found':found, 'obj':obj, 'namespace':ospace,
                 'ismagic':ismagic, 'isalias':isalias, 'parent':parent}
 
     def _ofind_property(self, oname, info):
         """Second part of object finding, to look for property details."""
         if info.found:
             # Get the docstring of the class property if it exists.
             path = oname.split('.')
             root = '.'.join(path[:-1])
             if info.parent is not None:
                 try:
                     target = getattr(info.parent, '__class__')
                     # The object belongs to a class instance.
                     try:
                         target = getattr(target, path[-1])
                         # The class defines the object.
                         if isinstance(target, property):
                             oname = root + '.__class__.' + path[-1]
                             info = Struct(self._ofind(oname))
                     except AttributeError: pass
                 except AttributeError: pass
 
         # We return either the new info or the unmodified input if the object
         # hadn't been found
         return info
 
     def _object_find(self, oname, namespaces=None):
         """Find an object and return a struct with info about it."""
         inf = Struct(self._ofind(oname, namespaces))
         return Struct(self._ofind_property(oname, inf))
 
     def _inspect(self, meth, oname, namespaces=None, **kw):
         """Generic interface to the inspector system.
 
         This function is meant to be called by pdef, pdoc & friends."""
         info = self._object_find(oname)
         if info.found:
             pmethod = getattr(self.inspector, meth)
             formatter = format_screen if info.ismagic else None
             if meth == 'pdoc':
                 pmethod(info.obj, oname, formatter)
             elif meth == 'pinfo':
                 pmethod(info.obj, oname, formatter, info, **kw)
             else:
                 pmethod(info.obj, oname)
         else:
             print 'Object `%s` not found.' % oname
             return 'not found'  # so callers can take other action
 
     def object_inspect(self, oname, detail_level=0):
         with self.builtin_trap:
             info = self._object_find(oname)
             if info.found:
                 return self.inspector.info(info.obj, oname, info=info,
                             detail_level=detail_level
                 )
             else:
                 return oinspect.object_info(name=oname, found=False)
 
     #-------------------------------------------------------------------------
     # Things related to history management
     #-------------------------------------------------------------------------
 
     def init_history(self):
         """Sets up the command history, and starts regular autosaves."""
         self.history_manager = HistoryManager(shell=self, config=self.config)
         self.configurables.append(self.history_manager)
 
     #-------------------------------------------------------------------------
     # Things related to exception handling and tracebacks (not debugging)
     #-------------------------------------------------------------------------
 
     def init_traceback_handlers(self, custom_exceptions):
         # Syntax error handler.
         self.SyntaxTB = ultratb.SyntaxTB(color_scheme='NoColor')
 
         # The interactive one is initialized with an offset, meaning we always
         # want to remove the topmost item in the traceback, which is our own
         # internal code. Valid modes: ['Plain','Context','Verbose']
         self.InteractiveTB = ultratb.AutoFormattedTB(mode = 'Plain',
                                                      color_scheme='NoColor',
                                                      tb_offset = 1,
                                    check_cache=self.compile.check_cache)
 
         # The instance will store a pointer to the system-wide exception hook,
         # so that runtime code (such as magics) can access it.  This is because
         # during the read-eval loop, it may get temporarily overwritten.
         self.sys_excepthook = sys.excepthook
 
         # and add any custom exception handlers the user may have specified
         self.set_custom_exc(*custom_exceptions)
 
         # Set the exception mode
         self.InteractiveTB.set_mode(mode=self.xmode)
 
     def set_custom_exc(self, exc_tuple, handler):
         """set_custom_exc(exc_tuple,handler)
 
         Set a custom exception handler, which will be called if any of the
         exceptions in exc_tuple occur in the mainloop (specifically, in the
         run_code() method).
 
         Parameters
         ----------
 
         exc_tuple : tuple of exception classes
             A *tuple* of exception classes, for which to call the defined
             handler.  It is very important that you use a tuple, and NOT A
             LIST here, because of the way Python's except statement works.  If
             you only want to trap a single exception, use a singleton tuple::
 
                 exc_tuple == (MyCustomException,)
 
         handler : callable
             handler must have the following signature::
 
                 def my_handler(self, etype, value, tb, tb_offset=None):
                     ...
                     return structured_traceback
 
             Your handler must return a structured traceback (a list of strings),
             or None.
 
             This will be made into an instance method (via types.MethodType)
             of IPython itself, and it will be called if any of the exceptions
             listed in the exc_tuple are caught. If the handler is None, an
             internal basic one is used, which just prints basic info.
 
             To protect IPython from crashes, if your handler ever raises an
             exception or returns an invalid result, it will be immediately
             disabled.
 
         WARNING: by putting in your own exception handler into IPython's main
         execution loop, you run a very good chance of nasty crashes.  This
         facility should only be used if you really know what you are doing."""
 
         assert type(exc_tuple)==type(()) , \
                "The custom exceptions must be given AS A TUPLE."
 
         def dummy_handler(self,etype,value,tb,tb_offset=None):
             print '*** Simple custom exception handler ***'
             print 'Exception type :',etype
             print 'Exception value:',value
             print 'Traceback      :',tb
             #print 'Source code    :','\n'.join(self.buffer)
         
         def validate_stb(stb):
             """validate structured traceback return type
             
             return type of CustomTB *should* be a list of strings, but allow
             single strings or None, which are harmless.
             
             This function will *always* return a list of strings,
             and will raise a TypeError if stb is inappropriate.
             """
             msg = "CustomTB must return list of strings, not %r" % stb
             if stb is None:
                 return []
             elif isinstance(stb, basestring):
                 return [stb]
             elif not isinstance(stb, list):
                 raise TypeError(msg)
             # it's a list
             for line in stb:
                 # check every element
                 if not isinstance(line, basestring):
                     raise TypeError(msg)
             return stb
 
         if handler is None:
             wrapped = dummy_handler
         else:
             def wrapped(self,etype,value,tb,tb_offset=None):
                 """wrap CustomTB handler, to protect IPython from user code
                 
                 This makes it harder (but not impossible) for custom exception
                 handlers to crash IPython.
                 """
                 try:
                     stb = handler(self,etype,value,tb,tb_offset=tb_offset)
                     return validate_stb(stb)
                 except:
                     # clear custom handler immediately
                     self.set_custom_exc((), None)
                     print >> io.stderr, "Custom TB Handler failed, unregistering"
                     # show the exception in handler first
                     stb = self.InteractiveTB.structured_traceback(*sys.exc_info())
                     print >> io.stdout, self.InteractiveTB.stb2text(stb)
                     print >> io.stdout, "The original exception:"
                     stb = self.InteractiveTB.structured_traceback(
                                             (etype,value,tb), tb_offset=tb_offset
                     )
                 return stb
 
         self.CustomTB = types.MethodType(wrapped,self)
         self.custom_exceptions = exc_tuple
 
     def excepthook(self, etype, value, tb):
       """One more defense for GUI apps that call sys.excepthook.
 
       GUI frameworks like wxPython trap exceptions and call
       sys.excepthook themselves.  I guess this is a feature that
       enables them to keep running after exceptions that would
       otherwise kill their mainloop. This is a bother for IPython
       which excepts to catch all of the program exceptions with a try:
       except: statement.
 
       Normally, IPython sets sys.excepthook to a CrashHandler instance, so if
       any app directly invokes sys.excepthook, it will look to the user like
       IPython crashed.  In order to work around this, we can disable the
       CrashHandler and replace it with this excepthook instead, which prints a
       regular traceback using our InteractiveTB.  In this fashion, apps which
       call sys.excepthook will generate a regular-looking exception from
       IPython, and the CrashHandler will only be triggered by real IPython
       crashes.
 
       This hook should be used sparingly, only in places which are not likely
       to be true IPython errors.
       """
       self.showtraceback((etype,value,tb),tb_offset=0)
 
     def _get_exc_info(self, exc_tuple=None):
         """get exc_info from a given tuple, sys.exc_info() or sys.last_type etc.
         
         Ensures sys.last_type,value,traceback hold the exc_info we found,
         from whichever source.
         
         raises ValueError if none of these contain any information
         """
         if exc_tuple is None:
             etype, value, tb = sys.exc_info()
         else:
             etype, value, tb = exc_tuple
 
         if etype is None:
             if hasattr(sys, 'last_type'):
                 etype, value, tb = sys.last_type, sys.last_value, \
                                    sys.last_traceback
         
         if etype is None:
             raise ValueError("No exception to find")
         
         # Now store the exception info in sys.last_type etc.
         # WARNING: these variables are somewhat deprecated and not
         # necessarily safe to use in a threaded environment, but tools
         # like pdb depend on their existence, so let's set them.  If we
         # find problems in the field, we'll need to revisit their use.
         sys.last_type = etype
         sys.last_value = value
         sys.last_traceback = tb
         
         return etype, value, tb
     
 
     def showtraceback(self,exc_tuple = None,filename=None,tb_offset=None,
                       exception_only=False):
         """Display the exception that just occurred.
 
         If nothing is known about the exception, this is the method which
         should be used throughout the code for presenting user tracebacks,
         rather than directly invoking the InteractiveTB object.
 
         A specific showsyntaxerror() also exists, but this method can take
         care of calling it if needed, so unless you are explicitly catching a
         SyntaxError exception, don't try to analyze the stack manually and
         simply call this method."""
 
         try:
             try:
                 etype, value, tb = self._get_exc_info(exc_tuple)
             except ValueError:
                 self.write_err('No traceback available to show.\n')
                 return
             
             if etype is SyntaxError:
                 # Though this won't be called by syntax errors in the input
                 # line, there may be SyntaxError cases with imported code.
                 self.showsyntaxerror(filename)
             elif etype is UsageError:
                 self.write_err("UsageError: %s" % value)
             elif issubclass(etype, RemoteError):
                 # IPython.parallel remote exceptions.
                 # Draw the remote traceback, not the local one.
                 self._showtraceback(etype, value, value.render_traceback())
             else:
                 if exception_only:
                     stb = ['An exception has occurred, use %tb to see '
                            'the full traceback.\n']
                     stb.extend(self.InteractiveTB.get_exception_only(etype,
                                                                      value))
                 else:
                     stb = self.InteractiveTB.structured_traceback(etype,
                                             value, tb, tb_offset=tb_offset)
 
                     self._showtraceback(etype, value, stb)
                     if self.call_pdb:
                         # drop into debugger
                         self.debugger(force=True)
                     return
 
                 # Actually show the traceback
                 self._showtraceback(etype, value, stb)
 
         except KeyboardInterrupt:
             self.write_err("\nKeyboardInterrupt\n")
 
     def _showtraceback(self, etype, evalue, stb):
         """Actually show a traceback.
 
         Subclasses may override this method to put the traceback on a different
         place, like a side channel.
         """
         print >> io.stdout, self.InteractiveTB.stb2text(stb)
 
     def showsyntaxerror(self, filename=None):
         """Display the syntax error that just occurred.
 
         This doesn't display a stack trace because there isn't one.
 
         If a filename is given, it is stuffed in the exception instead
         of what was there before (because Python's parser always uses
         "<string>" when reading from a string).
         """
         etype, value, last_traceback = self._get_exc_info()
 
         if filename and etype is SyntaxError:
             try:
                 value.filename = filename
             except:
                 # Not the format we expect; leave it alone
                 pass
         
         stb = self.SyntaxTB.structured_traceback(etype, value, [])
         self._showtraceback(etype, value, stb)
 
     # This is overridden in TerminalInteractiveShell to show a message about
     # the %paste magic.
     def showindentationerror(self):
         """Called by run_cell when there's an IndentationError in code entered
         at the prompt.
 
         This is overridden in TerminalInteractiveShell to show a message about
         the %paste magic."""
         self.showsyntaxerror()
 
     #-------------------------------------------------------------------------
     # Things related to readline
     #-------------------------------------------------------------------------
 
     def init_readline(self):
         """Command history completion/saving/reloading."""
 
         if self.readline_use:
             import IPython.utils.rlineimpl as readline
 
         self.rl_next_input = None
         self.rl_do_indent = False
 
         if not self.readline_use or not readline.have_readline:
             self.has_readline = False
             self.readline = None
             # Set a number of methods that depend on readline to be no-op
             self.readline_no_record = no_op_context
             self.set_readline_completer = no_op
             self.set_custom_completer = no_op
             self.set_completer_frame = no_op
             if self.readline_use:
                 warn('Readline services not available or not loaded.')
         else:
             self.has_readline = True
             self.readline = readline
             sys.modules['readline'] = readline
 
             # Platform-specific configuration
             if os.name == 'nt':
                 # FIXME - check with Frederick to see if we can harmonize
                 # naming conventions with pyreadline to avoid this
                 # platform-dependent check
                 self.readline_startup_hook = readline.set_pre_input_hook
             else:
                 self.readline_startup_hook = readline.set_startup_hook
 
             # Load user's initrc file (readline config)
             # Or if libedit is used, load editrc.
             inputrc_name = os.environ.get('INPUTRC')
             if inputrc_name is None:
                 inputrc_name = '.inputrc'
                 if readline.uses_libedit:
                     inputrc_name = '.editrc'
                 inputrc_name = os.path.join(self.home_dir, inputrc_name)
             if os.path.isfile(inputrc_name):
                 try:
                     readline.read_init_file(inputrc_name)
                 except:
                     warn('Problems reading readline initialization file <%s>'
                          % inputrc_name)
 
             # Configure readline according to user's prefs
             # This is only done if GNU readline is being used.  If libedit
             # is being used (as on Leopard) the readline config is
             # not run as the syntax for libedit is different.
             if not readline.uses_libedit:
                 for rlcommand in self.readline_parse_and_bind:
                     #print "loading rl:",rlcommand  # dbg
                     readline.parse_and_bind(rlcommand)
 
             # Remove some chars from the delimiters list.  If we encounter
             # unicode chars, discard them.
             delims = readline.get_completer_delims()
             if not py3compat.PY3:
                 delims = delims.encode("ascii", "ignore")
             for d in self.readline_remove_delims:
                 delims = delims.replace(d, "")
             delims = delims.replace(ESC_MAGIC, '')
             readline.set_completer_delims(delims)
             # otherwise we end up with a monster history after a while:
             readline.set_history_length(self.history_length)
 
             self.refill_readline_hist()
             self.readline_no_record = ReadlineNoRecord(self)
 
         # Configure auto-indent for all platforms
         self.set_autoindent(self.autoindent)
 
     def refill_readline_hist(self):
         # Load the last 1000 lines from history
         self.readline.clear_history()
         stdin_encoding = sys.stdin.encoding or "utf-8"
         last_cell = u""
         for _, _, cell in self.history_manager.get_tail(1000,
                                                         include_latest=True):
             # Ignore blank lines and consecutive duplicates
             cell = cell.rstrip()
             if cell and (cell != last_cell):
                 if self.multiline_history:
                       self.readline.add_history(py3compat.unicode_to_str(cell,
                                                                 stdin_encoding))
                 else:
                     for line in cell.splitlines():
                         self.readline.add_history(py3compat.unicode_to_str(line,
                                                                 stdin_encoding))
                 last_cell = cell
 
     def set_next_input(self, s):
         """ Sets the 'default' input string for the next command line.
 
         Requires readline.
 
         Example:
 
         [D:\ipython]|1> _ip.set_next_input("Hello Word")
         [D:\ipython]|2> Hello Word_  # cursor is here
         """
         self.rl_next_input = py3compat.cast_bytes_py2(s)
 
     # Maybe move this to the terminal subclass?
     def pre_readline(self):
         """readline hook to be used at the start of each line.
 
         Currently it handles auto-indent only."""
 
         if self.rl_do_indent:
             self.readline.insert_text(self._indent_current_str())
         if self.rl_next_input is not None:
             self.readline.insert_text(self.rl_next_input)
             self.rl_next_input = None
 
     def _indent_current_str(self):
         """return the current level of indentation as a string"""
         return self.input_splitter.indent_spaces * ' '
 
     #-------------------------------------------------------------------------
     # Things related to text completion
     #-------------------------------------------------------------------------
 
     def init_completer(self):
         """Initialize the completion machinery.
 
         This creates completion machinery that can be used by client code,
         either interactively in-process (typically triggered by the readline
         library), programatically (such as in test suites) or out-of-prcess
         (typically over the network by remote frontends).
         """
         from IPython.core.completer import IPCompleter
         from IPython.core.completerlib import (module_completer,
                 magic_run_completer, cd_completer, reset_completer)
 
         self.Completer = IPCompleter(shell=self,
                                      namespace=self.user_ns,
                                      global_namespace=self.user_global_ns,
                                      alias_table=self.alias_manager.alias_table,
                                      use_readline=self.has_readline,
                                      config=self.config,
                                      )
         self.configurables.append(self.Completer)
 
         # Add custom completers to the basic ones built into IPCompleter
         sdisp = self.strdispatchers.get('complete_command', StrDispatch())
         self.strdispatchers['complete_command'] = sdisp
         self.Completer.custom_completers = sdisp
 
         self.set_hook('complete_command', module_completer, str_key = 'import')
         self.set_hook('complete_command', module_completer, str_key = 'from')
         self.set_hook('complete_command', magic_run_completer, str_key = '%run')
         self.set_hook('complete_command', cd_completer, str_key = '%cd')
         self.set_hook('complete_command', reset_completer, str_key = '%reset')
 
         # Only configure readline if we truly are using readline.  IPython can
         # do tab-completion over the network, in GUIs, etc, where readline
         # itself may be absent
         if self.has_readline:
             self.set_readline_completer()
 
     def complete(self, text, line=None, cursor_pos=None):
         """Return the completed text and a list of completions.
 
         Parameters
         ----------
 
            text : string
              A string of text to be completed on.  It can be given as empty and
              instead a line/position pair are given.  In this case, the
              completer itself will split the line like readline does.
 
            line : string, optional
              The complete line that text is part of.
 
            cursor_pos : int, optional
              The position of the cursor on the input line.
 
         Returns
         -------
           text : string
             The actual text that was completed.
 
           matches : list
             A sorted list with all possible completions.
 
         The optional arguments allow the completion to take more context into
         account, and are part of the low-level completion API.
 
         This is a wrapper around the completion mechanism, similar to what
         readline does at the command line when the TAB key is hit.  By
         exposing it as a method, it can be used by other non-readline
         environments (such as GUIs) for text completion.
 
         Simple usage example:
 
         In [1]: x = 'hello'
 
         In [2]: _ip.complete('x.l')
         Out[2]: ('x.l', ['x.ljust', 'x.lower', 'x.lstrip'])
         """
 
         # Inject names into __builtin__ so we can complete on the added names.
         with self.builtin_trap:
             return self.Completer.complete(text, line, cursor_pos)
 
     def set_custom_completer(self, completer, pos=0):
         """Adds a new custom completer function.
 
         The position argument (defaults to 0) is the index in the completers
         list where you want the completer to be inserted."""
 
         newcomp = types.MethodType(completer,self.Completer)
         self.Completer.matchers.insert(pos,newcomp)
 
     def set_readline_completer(self):
         """Reset readline's completer to be our own."""
         self.readline.set_completer(self.Completer.rlcomplete)
 
     def set_completer_frame(self, frame=None):
         """Set the frame of the completer."""
         if frame:
             self.Completer.namespace = frame.f_locals
             self.Completer.global_namespace = frame.f_globals
         else:
             self.Completer.namespace = self.user_ns
             self.Completer.global_namespace = self.user_global_ns
 
     #-------------------------------------------------------------------------
     # Things related to magics
     #-------------------------------------------------------------------------
 
     def init_magics(self):
         from IPython.core import magics as m
         self.magics_manager = magic.MagicsManager(shell=self,
                                    confg=self.config,
                                    user_magics=m.UserMagics(self))
         self.configurables.append(self.magics_manager)
 
         # Expose as public API from the magics manager
         self.register_magics = self.magics_manager.register
         self.register_magic_function = self.magics_manager.register_function
         self.define_magic = self.magics_manager.define_magic
 
         self.register_magics(m.AutoMagics, m.BasicMagics, m.CodeMagics,
             m.ConfigMagics, m.DeprecatedMagics, m.ExecutionMagics,
             m.ExtensionMagics, m.HistoryMagics, m.LoggingMagics,
             m.NamespaceMagics, m.OSMagics, m.PylabMagics, m.ScriptMagics,
         )
 
         # FIXME: Move the color initialization to the DisplayHook, which
         # should be split into a prompt manager and displayhook. We probably
         # even need a centralize colors management object.
         self.magic('colors %s' % self.colors)
 
     def run_line_magic(self, magic_name, line):
         """Execute the given line magic.
 
         Parameters
         ----------
         magic_name : str
           Name of the desired magic function, without '%' prefix.
 
         line : str
           The rest of the input line as a single string.
         """
         fn = self.find_line_magic(magic_name)
         if fn is None:
             cm = self.find_cell_magic(magic_name)
             etpl = "Line magic function `%%%s` not found%s."
             extra = '' if cm is None else (' (But cell magic `%%%%%s` exists, '
                                     'did you mean that instead?)' % magic_name )
             error(etpl % (magic_name, extra))
         else:
             # Note: this is the distance in the stack to the user's frame.
             # This will need to be updated if the internal calling logic gets
             # refactored, or else we'll be expanding the wrong variables.
             stack_depth = 2
             magic_arg_s = self.var_expand(line, stack_depth)
             # Put magic args in a list so we can call with f(*a) syntax
             args = [magic_arg_s]
             # Grab local namespace if we need it:
             if getattr(fn, "needs_local_scope", False):
                 args.append(sys._getframe(stack_depth).f_locals)
             with self.builtin_trap:
                 result = fn(*args)
             return result
 
     def run_cell_magic(self, magic_name, line, cell):
         """Execute the given cell magic.
         
         Parameters
         ----------
         magic_name : str
           Name of the desired magic function, without '%' prefix.
 
         line : str
           The rest of the first input line as a single string.
 
         cell : str
           The body of the cell as a (possibly multiline) string.
         """
         fn = self.find_cell_magic(magic_name)
         if fn is None:
             lm = self.find_line_magic(magic_name)
             etpl = "Cell magic function `%%%%%s` not found%s."
             extra = '' if lm is None else (' (But line magic `%%%s` exists, '
                                     'did you mean that instead?)' % magic_name )
             error(etpl % (magic_name, extra))
         else:
             # Note: this is the distance in the stack to the user's frame.
             # This will need to be updated if the internal calling logic gets
             # refactored, or else we'll be expanding the wrong variables.
             stack_depth = 2
             magic_arg_s = self.var_expand(line, stack_depth)
             with self.builtin_trap:
                 result = fn(line, cell)
             return result
 
     def find_line_magic(self, magic_name):
         """Find and return a line magic by name.
 
         Returns None if the magic isn't found."""
         return self.magics_manager.magics['line'].get(magic_name)
 
     def find_cell_magic(self, magic_name):
         """Find and return a cell magic by name.
 
         Returns None if the magic isn't found."""
         return self.magics_manager.magics['cell'].get(magic_name)
 
     def find_magic(self, magic_name, magic_kind='line'):
         """Find and return a magic of the given type by name.
 
         Returns None if the magic isn't found."""
         return self.magics_manager.magics[magic_kind].get(magic_name)
 
     def magic(self, arg_s):
         """DEPRECATED. Use run_line_magic() instead.
 
         Call a magic function by name.
 
         Input: a string containing the name of the magic function to call and
         any additional arguments to be passed to the magic.
 
         magic('name -opt foo bar') is equivalent to typing at the ipython
         prompt:
 
         In[1]: %name -opt foo bar
 
         To call a magic without arguments, simply use magic('name').
 
         This provides a proper Python function to call IPython's magics in any
         valid Python code you can type at the interpreter, including loops and
         compound statements.
         """
         # TODO: should we issue a loud deprecation warning here?
         magic_name, _, magic_arg_s = arg_s.partition(' ')
         magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
         return self.run_line_magic(magic_name, magic_arg_s)
 
     #-------------------------------------------------------------------------
     # Things related to macros
     #-------------------------------------------------------------------------
 
     def define_macro(self, name, themacro):
         """Define a new macro
 
         Parameters
         ----------
         name : str
             The name of the macro.
         themacro : str or Macro
             The action to do upon invoking the macro.  If a string, a new
             Macro object is created by passing the string to it.
         """
 
         from IPython.core import macro
 
         if isinstance(themacro, basestring):
             themacro = macro.Macro(themacro)
         if not isinstance(themacro, macro.Macro):
             raise ValueError('A macro must be a string or a Macro instance.')
         self.user_ns[name] = themacro
 
     #-------------------------------------------------------------------------
     # Things related to the running of system commands
     #-------------------------------------------------------------------------
 
     def system_piped(self, cmd):
         """Call the given cmd in a subprocess, piping stdout/err
 
         Parameters
         ----------
         cmd : str
           Command to execute (can not end in '&', as background processes are
           not supported.  Should not be a command that expects input
           other than simple text.
         """
         if cmd.rstrip().endswith('&'):
             # this is *far* from a rigorous test
             # We do not support backgrounding processes because we either use
             # pexpect or pipes to read from.  Users can always just call
             # os.system() or use ip.system=ip.system_raw
             # if they really want a background process.
             raise OSError("Background processes not supported.")
 
         # we explicitly do NOT return the subprocess status code, because
         # a non-None value would trigger :func:`sys.displayhook` calls.
         # Instead, we store the exit_code in user_ns.
         self.user_ns['_exit_code'] = system(self.var_expand(cmd, depth=1))
 
     def system_raw(self, cmd):
         """Call the given cmd in a subprocess using os.system
 
         Parameters
         ----------
         cmd : str
           Command to execute.
         """
         cmd = self.var_expand(cmd, depth=1)
         # protect os.system from UNC paths on Windows, which it can't handle:
         if sys.platform == 'win32':
             from IPython.utils._process_win32 import AvoidUNCPath
             with AvoidUNCPath() as path:
                 if path is not None:
                     cmd = '"pushd %s &&"%s' % (path, cmd)
                 cmd = py3compat.unicode_to_str(cmd)
                 ec = os.system(cmd)
         else:
             cmd = py3compat.unicode_to_str(cmd)
             ec = os.system(cmd)
         
         # We explicitly do NOT return the subprocess status code, because
         # a non-None value would trigger :func:`sys.displayhook` calls.
         # Instead, we store the exit_code in user_ns.
         self.user_ns['_exit_code'] = ec
 
     # use piped system by default, because it is better behaved
     system = system_piped
 
     def getoutput(self, cmd, split=True, depth=0):
         """Get output (possibly including stderr) from a subprocess.
 
         Parameters
         ----------
         cmd : str
           Command to execute (can not end in '&', as background processes are
           not supported.
         split : bool, optional
           If True, split the output into an IPython SList.  Otherwise, an
           IPython LSString is returned.  These are objects similar to normal
           lists and strings, with a few convenience attributes for easier
           manipulation of line-based output.  You can use '?' on them for
           details.
         depth : int, optional
           How many frames above the caller are the local variables which should
           be expanded in the command string? The default (0) assumes that the
           expansion variables are in the stack frame calling this function.
         """
         if cmd.rstrip().endswith('&'):
             # this is *far* from a rigorous test
             raise OSError("Background processes not supported.")
         out = getoutput(self.var_expand(cmd, depth=depth+1))
         if split:
             out = SList(out.splitlines())
         else:
             out = LSString(out)
         return out
 
     #-------------------------------------------------------------------------
     # Things related to aliases
     #-------------------------------------------------------------------------
 
     def init_alias(self):
         self.alias_manager = AliasManager(shell=self, config=self.config)
         self.configurables.append(self.alias_manager)
         self.ns_table['alias'] = self.alias_manager.alias_table,
 
     #-------------------------------------------------------------------------
     # Things related to extensions and plugins
     #-------------------------------------------------------------------------
 
     def init_extension_manager(self):
         self.extension_manager = ExtensionManager(shell=self, config=self.config)
         self.configurables.append(self.extension_manager)
 
     def init_plugin_manager(self):
         self.plugin_manager = PluginManager(config=self.config)
         self.configurables.append(self.plugin_manager)
         
 
     #-------------------------------------------------------------------------
     # Things related to payloads
     #-------------------------------------------------------------------------
 
     def init_payload(self):
         self.payload_manager = PayloadManager(config=self.config)
         self.configurables.append(self.payload_manager)
 
     #-------------------------------------------------------------------------
     # Things related to the prefilter
     #-------------------------------------------------------------------------
 
     def init_prefilter(self):
         self.prefilter_manager = PrefilterManager(shell=self, config=self.config)
         self.configurables.append(self.prefilter_manager)
         # Ultimately this will be refactored in the new interpreter code, but
         # for now, we should expose the main prefilter method (there's legacy
         # code out there that may rely on this).
         self.prefilter = self.prefilter_manager.prefilter_lines
 
     def auto_rewrite_input(self, cmd):
         """Print to the screen the rewritten form of the user's command.
 
         This shows visual feedback by rewriting input lines that cause
         automatic calling to kick in, like::
 
           /f x
 
         into::
 
           ------> f(x)
 
         after the user's input prompt.  This helps the user understand that the
         input line was transformed automatically by IPython.
         """
         if not self.show_rewritten_input:
             return
         
         rw = self.prompt_manager.render('rewrite') + cmd
 
         try:
             # plain ascii works better w/ pyreadline, on some machines, so
             # we use it and only print uncolored rewrite if we have unicode
             rw = str(rw)
             print >> io.stdout, rw
         except UnicodeEncodeError:
             print "------> " + cmd
 
     #-------------------------------------------------------------------------
     # Things related to extracting values/expressions from kernel and user_ns
     #-------------------------------------------------------------------------
 
     def _simple_error(self):
         etype, value = sys.exc_info()[:2]
         return u'[ERROR] {e.__name__}: {v}'.format(e=etype, v=value)
 
     def user_variables(self, names):
         """Get a list of variable names from the user's namespace.
 
         Parameters
         ----------
         names : list of strings
           A list of names of variables to be read from the user namespace.
 
         Returns
         -------
         A dict, keyed by the input names and with the repr() of each value.
         """
         out = {}
         user_ns = self.user_ns
         for varname in names:
             try:
                 value = repr(user_ns[varname])
             except:
                 value = self._simple_error()
             out[varname] = value
         return out
 
     def user_expressions(self, expressions):
         """Evaluate a dict of expressions in the user's namespace.
 
         Parameters
         ----------
         expressions : dict
           A dict with string keys and string values.  The expression values
           should be valid Python expressions, each of which will be evaluated
           in the user namespace.
 
         Returns
         -------
         A dict, keyed like the input expressions dict, with the repr() of each
         value.
         """
         out = {}
         user_ns = self.user_ns
         global_ns = self.user_global_ns
         for key, expr in expressions.iteritems():
             try:
                 value = repr(eval(expr, global_ns, user_ns))
             except:
                 value = self._simple_error()
             out[key] = value
         return out
 
     #-------------------------------------------------------------------------
     # Things related to the running of code
     #-------------------------------------------------------------------------
 
     def ex(self, cmd):
         """Execute a normal python statement in user namespace."""
         with self.builtin_trap:
             exec cmd in self.user_global_ns, self.user_ns
 
     def ev(self, expr):
         """Evaluate python expression expr in user namespace.
 
         Returns the result of evaluation
         """
         with self.builtin_trap:
             return eval(expr, self.user_global_ns, self.user_ns)
 
     def safe_execfile(self, fname, *where, **kw):
         """A safe version of the builtin execfile().
 
         This version will never throw an exception, but instead print
         helpful error messages to the screen.  This only works on pure
         Python files with the .py extension.
 
         Parameters
         ----------
         fname : string
             The name of the file to be executed.
         where : tuple
             One or two namespaces, passed to execfile() as (globals,locals).
             If only one is given, it is passed as both.
         exit_ignore : bool (False)
             If True, then silence SystemExit for non-zero status (it is always
             silenced for zero status, as it is so common).
         raise_exceptions : bool (False)
             If True raise exceptions everywhere. Meant for testing.
 
         """
         kw.setdefault('exit_ignore', False)
         kw.setdefault('raise_exceptions', False)
 
         fname = os.path.abspath(os.path.expanduser(fname))
 
         # Make sure we can open the file
         try:
             with open(fname) as thefile:
                 pass
         except:
             warn('Could not open file <%s> for safe execution.' % fname)
             return
 
         # Find things also in current directory.  This is needed to mimic the
         # behavior of running a script from the system command line, where
         # Python inserts the script's directory into sys.path
         dname = os.path.dirname(fname)
 
         with prepended_to_syspath(dname):
             try:
                 py3compat.execfile(fname,*where)
-            except SystemExit, status:
+            except SystemExit as status:
                 # If the call was made with 0 or None exit status (sys.exit(0)
                 # or sys.exit() ), don't bother showing a traceback, as both of
                 # these are considered normal by the OS:
                 # > python -c'import sys;sys.exit(0)'; echo $?
                 # 0
                 # > python -c'import sys;sys.exit()'; echo $?
                 # 0
                 # For other exit status, we show the exception unless
                 # explicitly silenced, but only in short form.
                 if kw['raise_exceptions']:
                     raise
                 if status.code not in (0, None) and not kw['exit_ignore']:
                     self.showtraceback(exception_only=True)
             except:
                 if kw['raise_exceptions']:
                     raise
                 self.showtraceback()
 
     def safe_execfile_ipy(self, fname):
         """Like safe_execfile, but for .ipy files with IPython syntax.
 
         Parameters
         ----------
         fname : str
             The name of the file to execute.  The filename must have a
             .ipy extension.
         """
         fname = os.path.abspath(os.path.expanduser(fname))
 
         # Make sure we can open the file
         try:
             with open(fname) as thefile:
                 pass
         except:
             warn('Could not open file <%s> for safe execution.' % fname)
             return
 
         # Find things also in current directory.  This is needed to mimic the
         # behavior of running a script from the system command line, where
         # Python inserts the script's directory into sys.path
         dname = os.path.dirname(fname)
 
         with prepended_to_syspath(dname):
             try:
                 with open(fname) as thefile:
                     # self.run_cell currently captures all exceptions
                     # raised in user code.  It would be nice if there were
                     # versions of runlines, execfile that did raise, so
                     # we could catch the errors.
                     self.run_cell(thefile.read(), store_history=False)
             except:
                 self.showtraceback()
                 warn('Unknown failure executing file: <%s>' % fname)
 
     def safe_run_module(self, mod_name, where):
         """A safe version of runpy.run_module().
 
         This version will never throw an exception, but instead print
         helpful error messages to the screen.
 
         Parameters
         ----------
         mod_name : string
             The name of the module to be executed.
         where : dict
             The globals namespace.
         """
         try:
             where.update(
                 runpy.run_module(str(mod_name), run_name="__main__",
                                  alter_sys=True)
                 )
         except:
             self.showtraceback()
             warn('Unknown failure executing module: <%s>' % mod_name)
 
     def _run_cached_cell_magic(self, magic_name, line):
         """Special method to call a cell magic with the data stored in self.
         """
         cell = self._current_cell_magic_body
         self._current_cell_magic_body = None
         return self.run_cell_magic(magic_name, line, cell)
 
     def run_cell(self, raw_cell, store_history=False, silent=False):
         """Run a complete IPython cell.
 
         Parameters
         ----------
         raw_cell : str
           The code (including IPython code such as %magic functions) to run.
         store_history : bool
           If True, the raw and translated cell will be stored in IPython's
           history. For user code calling back into IPython's machinery, this
           should be set to False.
         silent : bool
           If True, avoid side-effets, such as implicit displayhooks, history,
           and logging.  silent=True forces store_history=False.
         """
         if (not raw_cell) or raw_cell.isspace():
             return
         
         if silent:
             store_history = False
 
         self.input_splitter.push(raw_cell)
 
         # Check for cell magics, which leave state behind.  This interface is
         # ugly, we need to do something cleaner later...  Now the logic is
         # simply that the input_splitter remembers if there was a cell magic,
         # and in that case we grab the cell body.
         if self.input_splitter.cell_magic_parts:
             self._current_cell_magic_body = \
                                ''.join(self.input_splitter.cell_magic_parts)
         cell = self.input_splitter.source_reset()
 
         with self.builtin_trap:
             prefilter_failed = False
             if len(cell.splitlines()) == 1:
                 try:
                     # use prefilter_lines to handle trailing newlines
                     # restore trailing newline for ast.parse
                     cell = self.prefilter_manager.prefilter_lines(cell) + '\n'
                 except AliasError as e:
                     error(e)
                     prefilter_failed = True
                 except Exception:
                     # don't allow prefilter errors to crash IPython
                     self.showtraceback()
                     prefilter_failed = True
 
             # Store raw and processed history
             if store_history:
                 self.history_manager.store_inputs(self.execution_count,
                                                   cell, raw_cell)
             if not silent:
                 self.logger.log(cell, raw_cell)
 
             if not prefilter_failed:
                 # don't run if prefilter failed
                 cell_name = self.compile.cache(cell, self.execution_count)
 
                 with self.display_trap:
                     try:
                         code_ast = self.compile.ast_parse(cell,
                                                           filename=cell_name)
                     except IndentationError:
                         self.showindentationerror()
                         if store_history:
                             self.execution_count += 1
                         return None
                     except (OverflowError, SyntaxError, ValueError, TypeError,
                             MemoryError):
                         self.showsyntaxerror()
                         if store_history:
                             self.execution_count += 1
                         return None
                     
                     interactivity = "none" if silent else self.ast_node_interactivity
                     self.run_ast_nodes(code_ast.body, cell_name,
                                        interactivity=interactivity)
                     
                     # Execute any registered post-execution functions.
                     # unless we are silent
                     post_exec = [] if silent else self._post_execute.iteritems()
                     
                     for func, status in post_exec:
                         if self.disable_failing_post_execute and not status:
                             continue
                         try:
                             func()
                         except KeyboardInterrupt:
                             print >> io.stderr, "\nKeyboardInterrupt"
                         except Exception:
                             # register as failing:
                             self._post_execute[func] = False
                             self.showtraceback()
                             print >> io.stderr, '\n'.join([
                                 "post-execution function %r produced an error." % func,
                                 "If this problem persists, you can disable failing post-exec functions with:",
                                 "",
                                 "    get_ipython().disable_failing_post_execute = True"
                             ])
 
         if store_history:
             # Write output to the database. Does nothing unless
             # history output logging is enabled.
             self.history_manager.store_output(self.execution_count)
             # Each cell is a *single* input, regardless of how many lines it has
             self.execution_count += 1
 
     def run_ast_nodes(self, nodelist, cell_name, interactivity='last_expr'):
         """Run a sequence of AST nodes. The execution mode depends on the
         interactivity parameter.
 
         Parameters
         ----------
         nodelist : list
           A sequence of AST nodes to run.
         cell_name : str
           Will be passed to the compiler as the filename of the cell. Typically
           the value returned by ip.compile.cache(cell).
         interactivity : str
           'all', 'last', 'last_expr' or 'none', specifying which nodes should be
           run interactively (displaying output from expressions). 'last_expr'
           will run the last node interactively only if it is an expression (i.e.
           expressions in loops or other blocks are not displayed. Other values
           for this parameter will raise a ValueError.
         """
         if not nodelist:
             return
 
         if interactivity == 'last_expr':
             if isinstance(nodelist[-1], ast.Expr):
                 interactivity = "last"
             else:
                 interactivity = "none"
 
         if interactivity == 'none':
             to_run_exec, to_run_interactive = nodelist, []
         elif interactivity == 'last':
             to_run_exec, to_run_interactive = nodelist[:-1], nodelist[-1:]
         elif interactivity == 'all':
             to_run_exec, to_run_interactive = [], nodelist
         else:
             raise ValueError("Interactivity was %r" % interactivity)
 
         exec_count = self.execution_count
 
         try:
             for i, node in enumerate(to_run_exec):
                 mod = ast.Module([node])
                 code = self.compile(mod, cell_name, "exec")
                 if self.run_code(code):
                     return True
 
             for i, node in enumerate(to_run_interactive):
                 mod = ast.Interactive([node])
                 code = self.compile(mod, cell_name, "single")
                 if self.run_code(code):
                     return True
 
             # Flush softspace
             if softspace(sys.stdout, 0):
                 print
 
         except:
             # It's possible to have exceptions raised here, typically by
             # compilation of odd code (such as a naked 'return' outside a
             # function) that did parse but isn't valid. Typically the exception
             # is a SyntaxError, but it's safest just to catch anything and show
             # the user a traceback.
 
             # We do only one try/except outside the loop to minimize the impact
             # on runtime, and also because if any node in the node list is
             # broken, we should stop execution completely.
             self.showtraceback()
 
         return False
 
     def run_code(self, code_obj):
         """Execute a code object.
 
         When an exception occurs, self.showtraceback() is called to display a
         traceback.
 
         Parameters
         ----------
         code_obj : code object
           A compiled code object, to be executed
 
         Returns
         -------
         False : successful execution.
         True : an error occurred.
         """
 
         # Set our own excepthook in case the user code tries to call it
         # directly, so that the IPython crash handler doesn't get triggered
         old_excepthook,sys.excepthook = sys.excepthook, self.excepthook
 
         # we save the original sys.excepthook in the instance, in case config
         # code (such as magics) needs access to it.
         self.sys_excepthook = old_excepthook
         outflag = 1  # happens in more places, so it's easier as default
         try:
             try:
                 self.hooks.pre_run_code_hook()
                 #rprint('Running code', repr(code_obj)) # dbg
                 exec code_obj in self.user_global_ns, self.user_ns
             finally:
                 # Reset our crash handler in place
                 sys.excepthook = old_excepthook
         except SystemExit:
             self.showtraceback(exception_only=True)
             warn("To exit: use 'exit', 'quit', or Ctrl-D.", level=1)
         except self.custom_exceptions:
             etype,value,tb = sys.exc_info()
             self.CustomTB(etype,value,tb)
         except:
             self.showtraceback()
         else:
             outflag = 0
         return outflag
 
     # For backwards compatibility
     runcode = run_code
 
     #-------------------------------------------------------------------------
     # Things related to GUI support and pylab
     #-------------------------------------------------------------------------
 
     def enable_gui(self, gui=None):
         raise NotImplementedError('Implement enable_gui in a subclass')
 
     def enable_pylab(self, gui=None, import_all=True):
         """Activate pylab support at runtime.
 
         This turns on support for matplotlib, preloads into the interactive
         namespace all of numpy and pylab, and configures IPython to correctly
         interact with the GUI event loop.  The GUI backend to be used can be
         optionally selected with the optional :param:`gui` argument.
 
         Parameters
         ----------
         gui : optional, string
 
           If given, dictates the choice of matplotlib GUI backend to use
           (should be one of IPython's supported backends, 'qt', 'osx', 'tk',
           'gtk', 'wx' or 'inline'), otherwise we use the default chosen by
           matplotlib (as dictated by the matplotlib build-time options plus the
           user's matplotlibrc configuration file).  Note that not all backends
           make sense in all contexts, for example a terminal ipython can't
           display figures inline.
         """
         from IPython.core.pylabtools import mpl_runner
         # We want to prevent the loading of pylab to pollute the user's
         # namespace as shown by the %who* magics, so we execute the activation
         # code in an empty namespace, and we update *both* user_ns and
         # user_ns_hidden with this information.
         ns = {}
         try:
             gui = pylab_activate(ns, gui, import_all, self)
         except KeyError:
             error("Backend %r not supported" % gui)
             return
         self.user_ns.update(ns)
         self.user_ns_hidden.update(ns)
         # Now we must activate the gui pylab wants to use, and fix %run to take
         # plot updates into account
         self.enable_gui(gui)
         self.magics_manager.registry['ExecutionMagics'].default_runner = \
         mpl_runner(self.safe_execfile)
 
     #-------------------------------------------------------------------------
     # Utilities
     #-------------------------------------------------------------------------
 
     def var_expand(self, cmd, depth=0, formatter=DollarFormatter()):
         """Expand python variables in a string.
 
         The depth argument indicates how many frames above the caller should
         be walked to look for the local namespace where to expand variables.
 
         The global namespace for expansion is always the user's interactive
         namespace.
         """
         ns = self.user_ns.copy()
         ns.update(sys._getframe(depth+1).f_locals)
         ns.pop('self', None)
         try:
             cmd = formatter.format(cmd, **ns)
         except Exception:
             # if formatter couldn't format, just let it go untransformed
             pass
         return cmd
 
     def mktempfile(self, data=None, prefix='ipython_edit_'):
         """Make a new tempfile and return its filename.
 
         This makes a call to tempfile.mktemp, but it registers the created
         filename internally so ipython cleans it up at exit time.
 
         Optional inputs:
 
           - data(None): if data is given, it gets written out to the temp file
           immediately, and the file is closed again."""
 
         filename = tempfile.mktemp('.py', prefix)
         self.tempfiles.append(filename)
 
         if data:
             tmp_file = open(filename,'w')
             tmp_file.write(data)
             tmp_file.close()
         return filename
 
     # TODO:  This should be removed when Term is refactored.
     def write(self,data):
         """Write a string to the default output"""
         io.stdout.write(data)
 
     # TODO:  This should be removed when Term is refactored.
     def write_err(self,data):
         """Write a string to the default error output"""
         io.stderr.write(data)
 
     def ask_yes_no(self, prompt, default=None):
         if self.quiet:
             return True
         return ask_yes_no(prompt,default)
 
     def show_usage(self):
         """Show a usage message"""
         page.page(IPython.core.usage.interactive_usage)
 
     def extract_input_lines(self, range_str, raw=False):
         """Return as a string a set of input history slices.
 
         Parameters
         ----------
         range_str : string
             The set of slices is given as a string, like "~5/6-~4/2 4:8 9",
             since this function is for use by magic functions which get their
             arguments as strings. The number before the / is the session
             number: ~n goes n back from the current session.
 
         Optional Parameters:
           - raw(False): by default, the processed input is used.  If this is
           true, the raw input history is used instead.
 
         Note that slices can be called with two notations:
 
         N:M -> standard python form, means including items N...(M-1).
 
         N-M -> include items N..M (closed endpoint)."""
         lines = self.history_manager.get_range_by_str(range_str, raw=raw)
         return "\n".join(x for _, _, x in lines)
 
     def find_user_code(self, target, raw=True, py_only=False):
         """Get a code string from history, file, url, or a string or macro.
 
         This is mainly used by magic functions.
 
         Parameters
         ----------
 
         target : str
 
           A string specifying code to retrieve. This will be tried respectively
           as: ranges of input history (see %history for syntax), url,
           correspnding .py file, filename, or an expression evaluating to a
           string or Macro in the user namespace.
 
         raw : bool
           If true (default), retrieve raw history. Has no effect on the other
           retrieval mechanisms.
 
         py_only : bool (default False)
           Only try to fetch python code, do not try alternative methods to decode file
           if unicode fails.
 
         Returns
         -------
         A string of code.
 
         ValueError is raised if nothing is found, and TypeError if it evaluates
         to an object of another type. In each case, .args[0] is a printable
         message.
         """
         code = self.extract_input_lines(target, raw=raw)  # Grab history
         if code:
             return code
         utarget = unquote_filename(target)
         try:
             if utarget.startswith(('http://', 'https://')):
                 return openpy.read_py_url(utarget, skip_encoding_cookie=True)
         except UnicodeDecodeError:
             if not py_only :
                 response = urllib.urlopen(target)
                 return response.read().decode('latin1')
             raise ValueError(("'%s' seem to be unreadable.") % utarget)
 
         potential_target = [target]
         try :
             potential_target.insert(0,get_py_filename(target))
         except IOError:
             pass
 
         for tgt in potential_target :
             if os.path.isfile(tgt):                        # Read file
                 try :
                     return openpy.read_py_file(tgt, skip_encoding_cookie=True)
                 except UnicodeDecodeError :
                     if not py_only :
                         with io_open(tgt,'r', encoding='latin1') as f :
                             return f.read()
                     raise ValueError(("'%s' seem to be unreadable.") % target)
 
         try:                                              # User namespace
             codeobj = eval(target, self.user_ns)
         except Exception:
             raise ValueError(("'%s' was not found in history, as a file, url, "
                                 "nor in the user namespace.") % target)
         if isinstance(codeobj, basestring):
             return codeobj
         elif isinstance(codeobj, Macro):
             return codeobj.value
 
         raise TypeError("%s is neither a string nor a macro." % target,
                         codeobj)
 
     #-------------------------------------------------------------------------
     # Things related to IPython exiting
     #-------------------------------------------------------------------------
     def atexit_operations(self):
         """This will be executed at the time of exit.
 
         Cleanup operations and saving of persistent data that is done
         unconditionally by IPython should be performed here.
 
         For things that may depend on startup flags or platform specifics (such
         as having readline or not), register a separate atexit function in the
         code that has the appropriate information, rather than trying to
         clutter
         """
         # Close the history session (this stores the end time and line count)
         # this must be *before* the tempfile cleanup, in case of temporary
         # history db
         self.history_manager.end_session()
 
         # Cleanup all tempfiles left around
         for tfile in self.tempfiles:
             try:
                 os.unlink(tfile)
             except OSError:
                 pass
 
         # Clear all user namespaces to release all references cleanly.
         self.reset(new_session=False)
 
         # Run user hooks
         self.hooks.shutdown_hook()
 
     def cleanup(self):
         self.restore_sys_module_state()
 
 
 class InteractiveShellABC(object):
     """An abstract base class for InteractiveShell."""
     __metaclass__ = abc.ABCMeta
 
 InteractiveShellABC.register(InteractiveShell)

IPython/core/magic.py

@@ -1,617 +1,617 b''
 # encoding: utf-8
 """Magic functions for InteractiveShell.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2001 Janko Hauser <[e-mail]> and
 #  Copyright (C) 2001 Fernando Perez <[e-mail]>
 #  Copyright (C) 2008 The IPython Development Team
 
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 # Stdlib
 import os
 import re
 import sys
 import types
 from getopt import getopt, GetoptError
 
 # Our own
 from IPython.config.configurable import Configurable
 from IPython.core import oinspect
 from IPython.core.error import UsageError
 from IPython.core.inputsplitter import ESC_MAGIC, ESC_MAGIC2
 from IPython.external.decorator import decorator
 from IPython.utils.ipstruct import Struct
 from IPython.utils.process import arg_split
 from IPython.utils.text import dedent
 from IPython.utils.traitlets import Bool, Dict, Instance, MetaHasTraits
 from IPython.utils.warn import error, warn
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 # A dict we'll use for each class that has magics, used as temporary storage to
 # pass information between the @line/cell_magic method decorators and the
 # @magics_class class decorator, because the method decorators have no
 # access to the class when they run.  See for more details:
 # http://stackoverflow.com/questions/2366713/can-a-python-decorator-of-an-instance-method-access-the-class
 
 magics = dict(line={}, cell={})
 
 magic_kinds = ('line', 'cell')
 magic_spec = ('line', 'cell', 'line_cell')
 magic_escapes = dict(line=ESC_MAGIC, cell=ESC_MAGIC2)
 
 #-----------------------------------------------------------------------------
 # Utility classes and functions
 #-----------------------------------------------------------------------------
 
 class Bunch: pass
 
 
 def on_off(tag):
     """Return an ON/OFF string for a 1/0 input. Simple utility function."""
     return ['OFF','ON'][tag]
 
 
 def compress_dhist(dh):
     """Compress a directory history into a new one with at most 20 entries.
 
     Return a new list made from the first and last 10 elements of dhist after
     removal of duplicates.
     """
     head, tail = dh[:-10], dh[-10:]
 
     newhead = []
     done = set()
     for h in head:
         if h in done:
             continue
         newhead.append(h)
         done.add(h)
 
     return newhead + tail
 
 
 def needs_local_scope(func):
     """Decorator to mark magic functions which need to local scope to run."""
     func.needs_local_scope = True
     return func
 
 #-----------------------------------------------------------------------------
 # Class and method decorators for registering magics
 #-----------------------------------------------------------------------------
 
 def magics_class(cls):
     """Class decorator for all subclasses of the main Magics class.
 
     Any class that subclasses Magics *must* also apply this decorator, to
     ensure that all the methods that have been decorated as line/cell magics
     get correctly registered in the class instance.  This is necessary because
     when method decorators run, the class does not exist yet, so they
     temporarily store their information into a module global.  Application of
     this class decorator copies that global data to the class instance and
     clears the global.
 
     Obviously, this mechanism is not thread-safe, which means that the
     *creation* of subclasses of Magic should only be done in a single-thread
     context.  Instantiation of the classes has no restrictions.  Given that
     these classes are typically created at IPython startup time and before user
     application code becomes active, in practice this should not pose any
     problems.
     """
     cls.registered = True
     cls.magics = dict(line = magics['line'],
                       cell = magics['cell'])
     magics['line'] = {}
     magics['cell'] = {}
     return cls
 
 
 def record_magic(dct, magic_kind, magic_name, func):
     """Utility function to store a function as a magic of a specific kind.
 
     Parameters
     ----------
     dct : dict
       A dictionary with 'line' and 'cell' subdicts.
 
     magic_kind : str
       Kind of magic to be stored.
 
     magic_name : str
       Key to store the magic as.
 
     func : function
       Callable object to store.
     """
     if magic_kind == 'line_cell':
         dct['line'][magic_name] = dct['cell'][magic_name] = func
     else:
         dct[magic_kind][magic_name] = func
 
 
 def validate_type(magic_kind):
     """Ensure that the given magic_kind is valid.
 
     Check that the given magic_kind is one of the accepted spec types (stored
     in the global `magic_spec`), raise ValueError otherwise.
     """
     if magic_kind not in magic_spec:
         raise ValueError('magic_kind must be one of %s, %s given' %
                          magic_kinds, magic_kind)
 
 
 # The docstrings for the decorator below will be fairly similar for the two
 # types (method and function), so we generate them here once and reuse the
 # templates below.
 _docstring_template = \
 """Decorate the given {0} as {1} magic.
 
 The decorator can be used with or without arguments, as follows.
 
 i) without arguments: it will create a {1} magic named as the {0} being
 decorated::
 
     @deco
     def foo(...)
 
 will create a {1} magic named `foo`.
 
 ii) with one string argument: which will be used as the actual name of the
 resulting magic::
 
     @deco('bar')
     def foo(...)
 
 will create a {1} magic named `bar`.
 """
 
 # These two are decorator factories.  While they are conceptually very similar,
 # there are enough differences in the details that it's simpler to have them
 # written as completely standalone functions rather than trying to share code
 # and make a single one with convoluted logic.
 
 def _method_magic_marker(magic_kind):
     """Decorator factory for methods in Magics subclasses.
     """
 
     validate_type(magic_kind)
 
     # This is a closure to capture the magic_kind.  We could also use a class,
     # but it's overkill for just that one bit of state.
     def magic_deco(arg):
         call = lambda f, *a, **k: f(*a, **k)
 
         if callable(arg):
             # "Naked" decorator call (just @foo, no args)
             func = arg
             name = func.func_name
             retval = decorator(call, func)
             record_magic(magics, magic_kind, name, name)
         elif isinstance(arg, basestring):
             # Decorator called with arguments (@foo('bar'))
             name = arg
             def mark(func, *a, **kw):
                 record_magic(magics, magic_kind, name, func.func_name)
                 return decorator(call, func)
             retval = mark
         else:
             raise TypeError("Decorator can only be called with "
                             "string or function")
         return retval
 
     # Ensure the resulting decorator has a usable docstring
     magic_deco.__doc__ = _docstring_template.format('method', magic_kind)
     return magic_deco
 
 
 def _function_magic_marker(magic_kind):
     """Decorator factory for standalone functions.
     """
     validate_type(magic_kind)
     
     # This is a closure to capture the magic_kind.  We could also use a class,
     # but it's overkill for just that one bit of state.
     def magic_deco(arg):
         call = lambda f, *a, **k: f(*a, **k)
 
         # Find get_ipython() in the caller's namespace
         caller = sys._getframe(1)
         for ns in ['f_locals', 'f_globals', 'f_builtins']:
             get_ipython = getattr(caller, ns).get('get_ipython')
             if get_ipython is not None:
                 break
         else:
             raise NameError('Decorator can only run in context where '
                             '`get_ipython` exists')
 
         ip = get_ipython()
 
         if callable(arg):
             # "Naked" decorator call (just @foo, no args)
             func = arg
             name = func.func_name
             ip.register_magic_function(func, magic_kind, name)
             retval = decorator(call, func)
         elif isinstance(arg, basestring):
             # Decorator called with arguments (@foo('bar'))
             name = arg
             def mark(func, *a, **kw):
                 ip.register_magic_function(func, magic_kind, name)
                 return decorator(call, func)
             retval = mark
         else:
             raise TypeError("Decorator can only be called with "
                              "string or function")
         return retval
 
     # Ensure the resulting decorator has a usable docstring
     ds = _docstring_template.format('function', magic_kind)
 
     ds += dedent("""
     Note: this decorator can only be used in a context where IPython is already
     active, so that the `get_ipython()` call succeeds.  You can therefore use
     it in your startup files loaded after IPython initializes, but *not* in the
     IPython configuration file itself, which is executed before IPython is
     fully up and running.  Any file located in the `startup` subdirectory of
     your configuration profile will be OK in this sense.
     """)
     
     magic_deco.__doc__ = ds
     return magic_deco
 
 
 # Create the actual decorators for public use
 
 # These three are used to decorate methods in class definitions
 line_magic = _method_magic_marker('line')
 cell_magic = _method_magic_marker('cell')
 line_cell_magic = _method_magic_marker('line_cell')
 
 # These three decorate standalone functions and perform the decoration
 # immediately.  They can only run where get_ipython() works
 register_line_magic = _function_magic_marker('line')
 register_cell_magic = _function_magic_marker('cell')
 register_line_cell_magic = _function_magic_marker('line_cell')
 
 #-----------------------------------------------------------------------------
 # Core Magic classes
 #-----------------------------------------------------------------------------
 
 class MagicsManager(Configurable):
     """Object that handles all magic-related functionality for IPython.
     """
     # Non-configurable class attributes
 
     # A two-level dict, first keyed by magic type, then by magic function, and
     # holding the actual callable object as value.  This is the dict used for
     # magic function dispatch
     magics = Dict
 
     # A registry of the original objects that we've been given holding magics.
     registry = Dict
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
 
     auto_magic = Bool(True, config=True, help=
         "Automatically call line magics without requiring explicit % prefix")
     
     _auto_status = [
         'Automagic is OFF, % prefix IS needed for line magics.',
         'Automagic is ON, % prefix IS NOT needed for line magics.']
 
     user_magics = Instance('IPython.core.magics.UserMagics')
 
     def __init__(self, shell=None, config=None, user_magics=None, **traits):
 
         super(MagicsManager, self).__init__(shell=shell, config=config,
                                            user_magics=user_magics, **traits)
         self.magics = dict(line={}, cell={})
         # Let's add the user_magics to the registry for uniformity, so *all*
         # registered magic containers can be found there.
         self.registry[user_magics.__class__.__name__] = user_magics
 
     def auto_status(self):
         """Return descriptive string with automagic status."""
         return self._auto_status[self.auto_magic]
     
     def lsmagic_info(self):
         magic_list = []
         for m_type in self.magics :
             for m_name,mgc in self.magics[m_type].items():
                 try :
                     magic_list.append({'name':m_name,'type':m_type,'class':mgc.im_class.__name__})
                 except AttributeError :
                     magic_list.append({'name':m_name,'type':m_type,'class':'Other'})
         return magic_list
 
     def lsmagic(self):
         """Return a dict of currently available magic functions.
 
         The return dict has the keys 'line' and 'cell', corresponding to the
         two types of magics we support.  Each value is a list of names.
         """
         return self.magics
 
     def lsmagic_docs(self, brief=False, missing=''):
         """Return dict of documentation of magic functions.
 
         The return dict has the keys 'line' and 'cell', corresponding to the
         two types of magics we support. Each value is a dict keyed by magic
         name whose value is the function docstring. If a docstring is
         unavailable, the value of `missing` is used instead.
 
         If brief is True, only the first line of each docstring will be returned.
         """
         docs = {}
         for m_type in self.magics:
             m_docs = {}
             for m_name, m_func in self.magics[m_type].iteritems():
                 if m_func.__doc__:
                     if brief:
                         m_docs[m_name] = m_func.__doc__.split('\n', 1)[0]
                     else:
                         m_docs[m_name] = m_func.__doc__.rstrip()
                 else:
                     m_docs[m_name] = missing
             docs[m_type] = m_docs
         return docs
 
     def register(self, *magic_objects):
         """Register one or more instances of Magics.
 
         Take one or more classes or instances of classes that subclass the main 
         `core.Magic` class, and register them with IPython to use the magic
         functions they provide.  The registration process will then ensure that
         any methods that have decorated to provide line and/or cell magics will
         be recognized with the `%x`/`%%x` syntax as a line/cell magic
         respectively.
 
         If classes are given, they will be instantiated with the default
         constructor.  If your classes need a custom constructor, you should
         instanitate them first and pass the instance.
 
         The provided arguments can be an arbitrary mix of classes and instances.
 
         Parameters
         ----------
         magic_objects : one or more classes or instances
         """
         # Start by validating them to ensure they have all had their magic
         # methods registered at the instance level
         for m in magic_objects:
             if not m.registered:
                 raise ValueError("Class of magics %r was constructed without "
                                  "the @register_magics class decorator")
             if type(m) in (type, MetaHasTraits):
                 # If we're given an uninstantiated class
                 m = m(shell=self.shell)
 
             # Now that we have an instance, we can register it and update the
             # table of callables
             self.registry[m.__class__.__name__] = m
             for mtype in magic_kinds:
                 self.magics[mtype].update(m.magics[mtype])
 
     def register_function(self, func, magic_kind='line', magic_name=None):
         """Expose a standalone function as magic function for IPython.
 
         This will create an IPython magic (line, cell or both) from a
         standalone function.  The functions should have the following
         signatures: 
 
         * For line magics: `def f(line)`
         * For cell magics: `def f(line, cell)`
         * For a function that does both: `def f(line, cell=None)`
 
         In the latter case, the function will be called with `cell==None` when
         invoked as `%f`, and with cell as a string when invoked as `%%f`.
 
         Parameters
         ----------
         func : callable
           Function to be registered as a magic.
 
         magic_kind : str
           Kind of magic, one of 'line', 'cell' or 'line_cell'
 
         magic_name : optional str
           If given, the name the magic will have in the IPython namespace.  By
           default, the name of the function itself is used.
         """
 
         # Create the new method in the user_magics and register it in the
         # global table
         validate_type(magic_kind)
         magic_name = func.func_name if magic_name is None else magic_name
         setattr(self.user_magics, magic_name, func)
         record_magic(self.magics, magic_kind, magic_name, func)
 
     def define_magic(self, name, func):
         """[Deprecated] Expose own function as magic function for IPython.
 
         Example::
 
             def foo_impl(self, parameter_s=''):
                 'My very own magic!. (Use docstrings, IPython reads them).'
                 print 'Magic function. Passed parameter is between < >:'
                 print '<%s>' % parameter_s
                 print 'The self object is:', self
 
             ip.define_magic('foo',foo_impl)
         """
         meth = types.MethodType(func, self.user_magics)
         setattr(self.user_magics, name, meth)
         record_magic(self.magics, 'line', name, meth)
 
 # Key base class that provides the central functionality for magics.
 
 class Magics(object):
     """Base class for implementing magic functions.
 
     Shell functions which can be reached as %function_name. All magic
     functions should accept a string, which they can parse for their own
     needs. This can make some functions easier to type, eg `%cd ../`
     vs. `%cd("../")`
 
     Classes providing magic functions need to subclass this class, and they
     MUST:
 
     - Use the method decorators `@line_magic` and `@cell_magic` to decorate
     individual methods as magic functions, AND
 
     - Use the class decorator `@magics_class` to ensure that the magic
     methods are properly registered at the instance level upon instance
     initialization.
 
     See :mod:`magic_functions` for examples of actual implementation classes.
     """
     # Dict holding all command-line options for each magic.
     options_table = None
     # Dict for the mapping of magic names to methods, set by class decorator
     magics = None
     # Flag to check that the class decorator was properly applied
     registered = False
     # Instance of IPython shell
     shell = None
 
     def __init__(self, shell):
         if not(self.__class__.registered):
             raise ValueError('Magics subclass without registration - '
                              'did you forget to apply @magics_class?')
         self.shell = shell
         self.options_table = {}
         # The method decorators are run when the instance doesn't exist yet, so
         # they can only record the names of the methods they are supposed to
         # grab.  Only now, that the instance exists, can we create the proper
         # mapping to bound methods.  So we read the info off the original names
         # table and replace each method name by the actual bound method.
         # But we mustn't clobber the *class* mapping, in case of multiple instances.
         class_magics = self.magics
         self.magics = {}
         for mtype in magic_kinds:
             tab = self.magics[mtype] = {}
             cls_tab = class_magics[mtype]
             for magic_name, meth_name in cls_tab.iteritems():
                 if isinstance(meth_name, basestring):
                     # it's a method name, grab it
                     tab[magic_name] = getattr(self, meth_name)
                 else:
                     # it's the real thing
                     tab[magic_name] = meth_name
 
     def arg_err(self,func):
         """Print docstring if incorrect arguments were passed"""
         print 'Error in arguments:'
         print oinspect.getdoc(func)
 
     def format_latex(self, strng):
         """Format a string for latex inclusion."""
 
         # Characters that need to be escaped for latex:
         escape_re = re.compile(r'(%|_|\$|#|&)',re.MULTILINE)
         # Magic command names as headers:
         cmd_name_re = re.compile(r'^(%s.*?):' % ESC_MAGIC,
                                  re.MULTILINE)
         # Magic commands
         cmd_re = re.compile(r'(?P<cmd>%s.+?\b)(?!\}\}:)' % ESC_MAGIC,
                             re.MULTILINE)
         # Paragraph continue
         par_re = re.compile(r'\\$',re.MULTILINE)
 
         # The "\n" symbol
         newline_re = re.compile(r'\\n')
 
         # Now build the string for output:
         #strng = cmd_name_re.sub(r'\n\\texttt{\\textsl{\\large \1}}:',strng)
         strng = cmd_name_re.sub(r'\n\\bigskip\n\\texttt{\\textbf{ \1}}:',
                                 strng)
         strng = cmd_re.sub(r'\\texttt{\g<cmd>}',strng)
         strng = par_re.sub(r'\\\\',strng)
         strng = escape_re.sub(r'\\\1',strng)
         strng = newline_re.sub(r'\\textbackslash{}n',strng)
         return strng
 
     def parse_options(self, arg_str, opt_str, *long_opts, **kw):
         """Parse options passed to an argument string.
 
         The interface is similar to that of getopt(), but it returns back a
         Struct with the options as keys and the stripped argument string still
         as a string.
 
         arg_str is quoted as a true sys.argv vector by using shlex.split.
         This allows us to easily expand variables, glob files, quote
         arguments, etc.
 
         Options:
           -mode: default 'string'. If given as 'list', the argument string is
           returned as a list (split on whitespace) instead of a string.
 
           -list_all: put all option values in lists. Normally only options
           appearing more than once are put in a list.
 
           -posix (True): whether to split the input line in POSIX mode or not,
           as per the conventions outlined in the shlex module from the
           standard library."""
 
         # inject default options at the beginning of the input line
         caller = sys._getframe(1).f_code.co_name
         arg_str = '%s %s' % (self.options_table.get(caller,''),arg_str)
 
         mode = kw.get('mode','string')
         if mode not in ['string','list']:
             raise ValueError,'incorrect mode given: %s' % mode
         # Get options
         list_all = kw.get('list_all',0)
         posix = kw.get('posix', os.name == 'posix')
         strict = kw.get('strict', True)
 
         # Check if we have more than one argument to warrant extra processing:
         odict = {}  # Dictionary with options
         args = arg_str.split()
         if len(args) >= 1:
             # If the list of inputs only has 0 or 1 thing in it, there's no
             # need to look for options
             argv = arg_split(arg_str, posix, strict)
             # Do regular option processing
             try:
                 opts,args = getopt(argv, opt_str, long_opts)
-            except GetoptError,e:
+            except GetoptError as e:
                 raise UsageError('%s ( allowed: "%s" %s)' % (e.msg,opt_str,
                                         " ".join(long_opts)))
             for o,a in opts:
                 if o.startswith('--'):
                     o = o[2:]
                 else:
                     o = o[1:]
                 try:
                     odict[o].append(a)
                 except AttributeError:
                     odict[o] = [odict[o],a]
                 except KeyError:
                     if list_all:
                         odict[o] = [a]
                     else:
                         odict[o] = a
 
         # Prepare opts,args for return
         opts = Struct(odict)
         if mode == 'string':
             args = ' '.join(args)
 
         return opts,args
 
     def default_option(self, fn, optstr):
         """Make an entry in the options_table for fn, with value optstr"""
 
         if fn not in self.lsmagic():
             error("%s is not a magic function" % fn)
         self.options_table[fn] = optstr

IPython/core/magics/code.py

@@ -1,521 +1,521 b''
 """Implementation of code management magic functions.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import inspect
 import io
 import json
 import os
 import sys
 from urllib2 import urlopen
 
 # Our own packages
 from IPython.core.error import TryNext, StdinNotImplementedError
 from IPython.core.macro import Macro
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.core.oinspect import find_file, find_source_lines
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import openpy
 from IPython.utils import py3compat
 from IPython.utils.io import file_read
 from IPython.utils.path import get_py_filename, unquote_filename
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
 #-----------------------------------------------------------------------------
 
 # Used for exception handling in magic_edit
 class MacroToEdit(ValueError): pass
 
 
 @magics_class
 class CodeMagics(Magics):
     """Magics related to code management (loading, saving, editing, ...)."""
 
     @line_magic
     def save(self, parameter_s=''):
         """Save a set of lines or a macro to a given filename.
 
         Usage:\\
           %save [options] filename n1-n2 n3-n4 ... n5 .. n6 ...
 
         Options:
 
           -r: use 'raw' input.  By default, the 'processed' history is used,
           so that magics are loaded in their transformed version to valid
           Python.  If this option is given, the raw input as typed as the
           command line is used instead.
           
           -f: force overwrite.  If file exists, %save will prompt for overwrite
           unless -f is given.
 
         This function uses the same syntax as %history for input ranges,
         then saves the lines to the filename you specify.
 
         It adds a '.py' extension to the file if you don't do so yourself, and
         it asks for confirmation before overwriting existing files.
 
         If `-r` option is used, the default extension is `.ipy`.
         """
 
         opts,args = self.parse_options(parameter_s,'fr',mode='list')
         raw = 'r' in opts
         force = 'f' in opts
         ext = u'.ipy' if raw else u'.py'
         fname, codefrom = unquote_filename(args[0]), " ".join(args[1:])
         if not fname.endswith((u'.py',u'.ipy')):
             fname += ext
         if os.path.isfile(fname) and not force:
             try:
                 overwrite = self.shell.ask_yes_no('File `%s` exists. Overwrite (y/[N])? ' % fname, default='n')
             except StdinNotImplementedError:
                 print "File `%s` exists. Use `%%save -f %s` to force overwrite" % (fname, parameter_s)
                 return
             if not overwrite :
                 print 'Operation cancelled.'
                 return
         try:
             cmds = self.shell.find_user_code(codefrom,raw)
         except (TypeError, ValueError) as e:
             print e.args[0]
             return
         with io.open(fname,'w', encoding="utf-8") as f:
             f.write(u"# coding: utf-8\n")
             f.write(py3compat.cast_unicode(cmds))
         print 'The following commands were written to file `%s`:' % fname
         print cmds
 
     @line_magic
     def pastebin(self, parameter_s=''):
         """Upload code to Github's Gist paste bin, returning the URL.
 
         Usage:\\
           %pastebin [-d "Custom description"] 1-7
 
         The argument can be an input history range, a filename, or the name of a
         string or macro.
 
         Options:
 
           -d: Pass a custom description for the gist. The default will say
               "Pasted from IPython".
         """
         opts, args = self.parse_options(parameter_s, 'd:')
 
         try:
             code = self.shell.find_user_code(args)
         except (ValueError, TypeError) as e:
             print e.args[0]
             return
 
         post_data = json.dumps({
           "description": opts.get('d', "Pasted from IPython"),
           "public": True,
           "files": {
             "file1.py": {
               "content": code
             }
           }
         }).encode('utf-8')
 
         response = urlopen("https://api.github.com/gists", post_data)
         response_data = json.loads(response.read().decode('utf-8'))
         return response_data['html_url']
 
     @line_magic
     def loadpy(self, arg_s):
         """Alias of `%load`
 
         `%loadpy` has gained some flexibility and droped the requirement of a `.py`
         extension. So it has been renamed simply into %load. You can look at
         `%load`'s docstring for more info.
         """
         self.load(arg_s)
 
     @line_magic
     def load(self, arg_s):
         """Load code into the current frontend.
 
         Usage:\\
           %load [options] source
 
           where source can be a filename, URL, input history range or macro
 
         Options:
         --------
           -y : Don't ask confirmation for loading source above 200 000 characters.
 
         This magic command can either take a local filename, a URL, an history
         range (see %history) or a macro as argument, it will prompt for
         confirmation before loading source with more than 200 000 characters, unless
         -y flag is passed or if the frontend does not support raw_input::
 
         %load myscript.py
         %load 7-27
         %load myMacro
         %load http://www.example.com/myscript.py
         """
         opts,args = self.parse_options(arg_s,'y')
 
         contents = self.shell.find_user_code(args)
         l = len(contents)
 
         # 200 000 is ~ 2500 full 80 caracter lines
         # so in average, more than 5000 lines
         if l > 200000 and 'y' not in opts:
             try:
                 ans = self.shell.ask_yes_no(("The text you're trying to load seems pretty big"\
                 " (%d characters). Continue (y/[N]) ?" % l), default='n' )
             except StdinNotImplementedError:
                 #asume yes if raw input not implemented
                 ans = True
 
             if ans is False :
                 print 'Operation cancelled.'
                 return
 
         self.shell.set_next_input(contents)
 
     @staticmethod
     def _find_edit_target(shell, args, opts, last_call):
         """Utility method used by magic_edit to find what to edit."""
 
         def make_filename(arg):
             "Make a filename from the given args"
             arg = unquote_filename(arg)
             try:
                 filename = get_py_filename(arg)
             except IOError:
                 # If it ends with .py but doesn't already exist, assume we want
                 # a new file.
                 if arg.endswith('.py'):
                     filename = arg
                 else:
                     filename = None
             return filename
 
         # Set a few locals from the options for convenience:
         opts_prev = 'p' in opts
         opts_raw = 'r' in opts
 
         # custom exceptions
         class DataIsObject(Exception): pass
 
         # Default line number value
         lineno = opts.get('n',None)
 
         if opts_prev:
             args = '_%s' % last_call[0]
             if not shell.user_ns.has_key(args):
                 args = last_call[1]
 
         # use last_call to remember the state of the previous call, but don't
         # let it be clobbered by successive '-p' calls.
         try:
             last_call[0] = shell.displayhook.prompt_count
             if not opts_prev:
                 last_call[1] = args
         except:
             pass
 
         # by default this is done with temp files, except when the given
         # arg is a filename
         use_temp = True
 
         data = ''
 
         # First, see if the arguments should be a filename.
         filename = make_filename(args)
         if filename:
             use_temp = False
         elif args:
             # Mode where user specifies ranges of lines, like in %macro.
             data = shell.extract_input_lines(args, opts_raw)
             if not data:
                 try:
                     # Load the parameter given as a variable. If not a string,
                     # process it as an object instead (below)
 
                     #print '*** args',args,'type',type(args)  # dbg
                     data = eval(args, shell.user_ns)
                     if not isinstance(data, basestring):
                         raise DataIsObject
 
                 except (NameError,SyntaxError):
                     # given argument is not a variable, try as a filename
                     filename = make_filename(args)
                     if filename is None:
                         warn("Argument given (%s) can't be found as a variable "
                              "or as a filename." % args)
                         return
                     use_temp = False
 
                 except DataIsObject:
                     # macros have a special edit function
                     if isinstance(data, Macro):
                         raise MacroToEdit(data)
 
                     # For objects, try to edit the file where they are defined
                     filename = find_file(data)
                     if filename:
                         if 'fakemodule' in filename.lower() and \
                             inspect.isclass(data):
                             # class created by %edit? Try to find source
                             # by looking for method definitions instead, the
                             # __module__ in those classes is FakeModule.
                             attrs = [getattr(data, aname) for aname in dir(data)]
                             for attr in attrs:
                                 if not inspect.ismethod(attr):
                                     continue
                                 filename = find_file(attr)
                                 if filename and \
                                   'fakemodule' not in filename.lower():
                                     # change the attribute to be the edit
                                     # target instead
                                     data = attr
                                     break
 
                         datafile = 1
                     if filename is None:
                         filename = make_filename(args)
                         datafile = 1
                         warn('Could not find file where `%s` is defined.\n'
                              'Opening a file named `%s`' % (args, filename))
                     # Now, make sure we can actually read the source (if it was
                     # in a temp file it's gone by now).
                     if datafile:
                         if lineno is None:
                             lineno = find_source_lines(data)
                         if lineno is None:
                             filename = make_filename(args)
                             if filename is None:
                                 warn('The file `%s` where `%s` was defined '
                                      'cannot be read.' % (filename, data))
                                 return
                     use_temp = False
 
         if use_temp:
             filename = shell.mktempfile(data)
             print 'IPython will make a temporary file named:',filename
 
         return filename, lineno, use_temp
 
     def _edit_macro(self,mname,macro):
         """open an editor with the macro data in a file"""
         filename = self.shell.mktempfile(macro.value)
         self.shell.hooks.editor(filename)
 
         # and make a new macro object, to replace the old one
         mfile = open(filename)
         mvalue = mfile.read()
         mfile.close()
         self.shell.user_ns[mname] = Macro(mvalue)
 
     @line_magic
     def ed(self, parameter_s=''):
         """Alias to %edit."""
         return self.edit(parameter_s)
 
     @skip_doctest
     @line_magic
     def edit(self, parameter_s='',last_call=['','']):
         """Bring up an editor and execute the resulting code.
 
         Usage:
           %edit [options] [args]
 
         %edit runs IPython's editor hook. The default version of this hook is
         set to call the editor specified by your $EDITOR environment variable.
         If this isn't found, it will default to vi under Linux/Unix and to
         notepad under Windows. See the end of this docstring for how to change
         the editor hook.
 
         You can also set the value of this editor via the
         ``TerminalInteractiveShell.editor`` option in your configuration file.
         This is useful if you wish to use a different editor from your typical
         default with IPython (and for Windows users who typically don't set
         environment variables).
 
         This command allows you to conveniently edit multi-line code right in
         your IPython session.
 
         If called without arguments, %edit opens up an empty editor with a
         temporary file and will execute the contents of this file when you
         close it (don't forget to save it!).
 
 
         Options:
 
         -n <number>: open the editor at a specified line number.  By default,
         the IPython editor hook uses the unix syntax 'editor +N filename', but
         you can configure this by providing your own modified hook if your
         favorite editor supports line-number specifications with a different
         syntax.
 
         -p: this will call the editor with the same data as the previous time
         it was used, regardless of how long ago (in your current session) it
         was.
 
         -r: use 'raw' input.  This option only applies to input taken from the
         user's history.  By default, the 'processed' history is used, so that
         magics are loaded in their transformed version to valid Python.  If
         this option is given, the raw input as typed as the command line is
         used instead.  When you exit the editor, it will be executed by
         IPython's own processor.
 
         -x: do not execute the edited code immediately upon exit. This is
         mainly useful if you are editing programs which need to be called with
         command line arguments, which you can then do using %run.
 
 
         Arguments:
 
         If arguments are given, the following possibilities exist:
 
         - If the argument is a filename, IPython will load that into the
           editor. It will execute its contents with execfile() when you exit,
           loading any code in the file into your interactive namespace.
 
         - The arguments are ranges of input history,  e.g. "7 ~1/4-6".
           The syntax is the same as in the %history magic.
 
         - If the argument is a string variable, its contents are loaded
           into the editor. You can thus edit any string which contains
           python code (including the result of previous edits).
 
         - If the argument is the name of an object (other than a string),
           IPython will try to locate the file where it was defined and open the
           editor at the point where it is defined. You can use `%edit function`
           to load an editor exactly at the point where 'function' is defined,
           edit it and have the file be executed automatically.
 
         - If the object is a macro (see %macro for details), this opens up your
           specified editor with a temporary file containing the macro's data.
           Upon exit, the macro is reloaded with the contents of the file.
 
         Note: opening at an exact line is only supported under Unix, and some
         editors (like kedit and gedit up to Gnome 2.8) do not understand the
         '+NUMBER' parameter necessary for this feature. Good editors like
         (X)Emacs, vi, jed, pico and joe all do.
 
         After executing your code, %edit will return as output the code you
         typed in the editor (except when it was an existing file). This way
         you can reload the code in further invocations of %edit as a variable,
         via _<NUMBER> or Out[<NUMBER>], where <NUMBER> is the prompt number of
         the output.
 
         Note that %edit is also available through the alias %ed.
 
         This is an example of creating a simple function inside the editor and
         then modifying it. First, start up the editor::
 
           In [1]: ed
           Editing... done. Executing edited code...
           Out[1]: 'def foo():\\n    print "foo() was defined in an editing
           session"\\n'
 
         We can then call the function foo()::
 
           In [2]: foo()
           foo() was defined in an editing session
 
         Now we edit foo.  IPython automatically loads the editor with the
         (temporary) file where foo() was previously defined::
 
           In [3]: ed foo
           Editing... done. Executing edited code...
 
         And if we call foo() again we get the modified version::
 
           In [4]: foo()
           foo() has now been changed!
 
         Here is an example of how to edit a code snippet successive
         times. First we call the editor::
 
           In [5]: ed
           Editing... done. Executing edited code...
           hello
           Out[5]: "print 'hello'\\n"
 
         Now we call it again with the previous output (stored in _)::
 
           In [6]: ed _
           Editing... done. Executing edited code...
           hello world
           Out[6]: "print 'hello world'\\n"
 
         Now we call it with the output #8 (stored in _8, also as Out[8])::
 
           In [7]: ed _8
           Editing... done. Executing edited code...
           hello again
           Out[7]: "print 'hello again'\\n"
 
 
         Changing the default editor hook:
 
         If you wish to write your own editor hook, you can put it in a
         configuration file which you load at startup time.  The default hook
         is defined in the IPython.core.hooks module, and you can use that as a
         starting example for further modifications.  That file also has
         general instructions on how to set a new hook for use once you've
         defined it."""
         opts,args = self.parse_options(parameter_s,'prxn:')
 
         try:
             filename, lineno, is_temp = self._find_edit_target(self.shell, 
                                                        args, opts, last_call)
         except MacroToEdit as e:
             self._edit_macro(args, e.args[0])
             return
 
         # do actual editing here
         print 'Editing...',
         sys.stdout.flush()
         try:
             # Quote filenames that may have spaces in them
             if ' ' in filename:
                 filename = "'%s'" % filename
             self.shell.hooks.editor(filename,lineno)
         except TryNext:
             warn('Could not open editor')
             return
 
         # XXX TODO: should this be generalized for all string vars?
         # For now, this is special-cased to blocks created by cpaste
         if args.strip() == 'pasted_block':
             self.shell.user_ns['pasted_block'] = file_read(filename)
 
         if 'x' in opts:  # -x prevents actual execution
             print
         else:
             print 'done. Executing edited code...'
             if 'r' in opts:    # Untranslated IPython code
                 self.shell.run_cell(file_read(filename),
                                                     store_history=False)
             else:
                 self.shell.safe_execfile(filename, self.shell.user_ns,
                                          self.shell.user_ns)
 
         if is_temp:
             try:
                 return open(filename).read()
-            except IOError,msg:
+            except IOError as msg:
                 if msg.filename == filename:
                     warn('File not found. Did you forget to save?')
                     return
                 else:
                     self.shell.showtraceback()

IPython/core/magics/namespace.py

@@ -1,700 +1,700 b''
 """Implementation of namespace-related magic functions.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import gc
 import re
 import sys
 
 # Our own packages
 from IPython.core import page
 from IPython.core.error import StdinNotImplementedError
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils.encoding import DEFAULT_ENCODING
 from IPython.utils.path import get_py_filename
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
 #-----------------------------------------------------------------------------
 
 @magics_class
 class NamespaceMagics(Magics):
     """Magics to manage various aspects of the user's namespace.
 
     These include listing variables, introspecting into them, etc.
     """
 
     @line_magic
     def pinfo(self, parameter_s='', namespaces=None):
         """Provide detailed information about an object.
 
         '%pinfo object' is just a synonym for object? or ?object."""
 
         #print 'pinfo par: <%s>' % parameter_s  # dbg
         # detail_level: 0 -> obj? , 1 -> obj??
         detail_level = 0
         # We need to detect if we got called as 'pinfo pinfo foo', which can
         # happen if the user types 'pinfo foo?' at the cmd line.
         pinfo,qmark1,oname,qmark2 = \
                re.match('(pinfo )?(\?*)(.*?)(\??$)',parameter_s).groups()
         if pinfo or qmark1 or qmark2:
             detail_level = 1
         if "*" in oname:
             self.psearch(oname)
         else:
             self.shell._inspect('pinfo', oname, detail_level=detail_level,
                                 namespaces=namespaces)
 
     @line_magic
     def pinfo2(self, parameter_s='', namespaces=None):
         """Provide extra detailed information about an object.
 
         '%pinfo2 object' is just a synonym for object?? or ??object."""
         self.shell._inspect('pinfo', parameter_s, detail_level=1,
                             namespaces=namespaces)
 
     @skip_doctest
     @line_magic
     def pdef(self, parameter_s='', namespaces=None):
         """Print the definition header for any callable object.
 
         If the object is a class, print the constructor information.
 
         Examples
         --------
         ::
 
           In [3]: %pdef urllib.urlopen
           urllib.urlopen(url, data=None, proxies=None)
         """
         self.shell._inspect('pdef',parameter_s, namespaces)
 
     @line_magic
     def pdoc(self, parameter_s='', namespaces=None):
         """Print the docstring for an object.
 
         If the given object is a class, it will print both the class and the
         constructor docstrings."""
         self.shell._inspect('pdoc',parameter_s, namespaces)
 
     @line_magic
     def psource(self, parameter_s='', namespaces=None):
         """Print (or run through pager) the source code for an object."""
         self.shell._inspect('psource',parameter_s, namespaces)
 
     @line_magic
     def pfile(self, parameter_s=''):
         """Print (or run through pager) the file where an object is defined.
 
         The file opens at the line where the object definition begins. IPython
         will honor the environment variable PAGER if set, and otherwise will
         do its best to print the file in a convenient form.
 
         If the given argument is not an object currently defined, IPython will
         try to interpret it as a filename (automatically adding a .py extension
         if needed). You can thus use %pfile as a syntax highlighting code
         viewer."""
 
         # first interpret argument as an object name
         out = self.shell._inspect('pfile',parameter_s)
         # if not, try the input as a filename
         if out == 'not found':
             try:
                 filename = get_py_filename(parameter_s)
-            except IOError,msg:
+            except IOError as msg:
                 print msg
                 return
             page.page(self.shell.inspector.format(open(filename).read()))
 
     @line_magic
     def psearch(self, parameter_s=''):
         """Search for object in namespaces by wildcard.
 
         %psearch [options] PATTERN [OBJECT TYPE]
 
         Note: ? can be used as a synonym for %psearch, at the beginning or at
         the end: both a*? and ?a* are equivalent to '%psearch a*'.  Still, the
         rest of the command line must be unchanged (options come first), so
         for example the following forms are equivalent
 
         %psearch -i a* function
         -i a* function?
         ?-i a* function
 
         Arguments:
 
           PATTERN
 
           where PATTERN is a string containing * as a wildcard similar to its
           use in a shell.  The pattern is matched in all namespaces on the
           search path. By default objects starting with a single _ are not
           matched, many IPython generated objects have a single
           underscore. The default is case insensitive matching. Matching is
           also done on the attributes of objects and not only on the objects
           in a module.
 
           [OBJECT TYPE]
 
           Is the name of a python type from the types module. The name is
           given in lowercase without the ending type, ex. StringType is
           written string. By adding a type here only objects matching the
           given type are matched. Using all here makes the pattern match all
           types (this is the default).
 
         Options:
 
           -a: makes the pattern match even objects whose names start with a
           single underscore.  These names are normally omitted from the
           search.
 
           -i/-c: make the pattern case insensitive/sensitive.  If neither of
           these options are given, the default is read from your configuration
           file, with the option ``InteractiveShell.wildcards_case_sensitive``.
           If this option is not specified in your configuration file, IPython's
           internal default is to do a case sensitive search.
 
           -e/-s NAMESPACE: exclude/search a given namespace.  The pattern you
           specify can be searched in any of the following namespaces:
           'builtin', 'user', 'user_global','internal', 'alias', where
           'builtin' and 'user' are the search defaults.  Note that you should
           not use quotes when specifying namespaces.
 
           'Builtin' contains the python module builtin, 'user' contains all
           user data, 'alias' only contain the shell aliases and no python
           objects, 'internal' contains objects used by IPython.  The
           'user_global' namespace is only used by embedded IPython instances,
           and it contains module-level globals.  You can add namespaces to the
           search with -s or exclude them with -e (these options can be given
           more than once).
 
         Examples
         --------
         ::
 
           %psearch a*            -> objects beginning with an a
           %psearch -e builtin a* -> objects NOT in the builtin space starting in a
           %psearch a* function   -> all functions beginning with an a
           %psearch re.e*         -> objects beginning with an e in module re
           %psearch r*.e*         -> objects that start with e in modules starting in r
           %psearch r*.* string   -> all strings in modules beginning with r
 
         Case sensitive search::
 
           %psearch -c a*         list all object beginning with lower case a
 
         Show objects beginning with a single _::
 
           %psearch -a _*         list objects beginning with a single underscore
         """
         try:
             parameter_s.encode('ascii')
         except UnicodeEncodeError:
             print 'Python identifiers can only contain ascii characters.'
             return
 
         # default namespaces to be searched
         def_search = ['user_local', 'user_global', 'builtin']
 
         # Process options/args
         opts,args = self.parse_options(parameter_s,'cias:e:',list_all=True)
         opt = opts.get
         shell = self.shell
         psearch = shell.inspector.psearch
 
         # select case options
         if opts.has_key('i'):
             ignore_case = True
         elif opts.has_key('c'):
             ignore_case = False
         else:
             ignore_case = not shell.wildcards_case_sensitive
 
         # Build list of namespaces to search from user options
         def_search.extend(opt('s',[]))
         ns_exclude = ns_exclude=opt('e',[])
         ns_search = [nm for nm in def_search if nm not in ns_exclude]
 
         # Call the actual search
         try:
             psearch(args,shell.ns_table,ns_search,
                     show_all=opt('a'),ignore_case=ignore_case)
         except:
             shell.showtraceback()
 
     @skip_doctest
     @line_magic
     def who_ls(self, parameter_s=''):
         """Return a sorted list of all interactive variables.
 
         If arguments are given, only variables of types matching these
         arguments are returned.
 
         Examples
         --------
 
         Define two variables and list them with who_ls::
 
           In [1]: alpha = 123
 
           In [2]: beta = 'test'
 
           In [3]: %who_ls
           Out[3]: ['alpha', 'beta']
 
           In [4]: %who_ls int
           Out[4]: ['alpha']
 
           In [5]: %who_ls str
           Out[5]: ['beta']
         """
 
         user_ns = self.shell.user_ns
         user_ns_hidden = self.shell.user_ns_hidden
         out = [ i for i in user_ns
                 if not i.startswith('_') \
                 and not i in user_ns_hidden ]
 
         typelist = parameter_s.split()
         if typelist:
             typeset = set(typelist)
             out = [i for i in out if type(user_ns[i]).__name__ in typeset]
 
         out.sort()
         return out
 
     @skip_doctest
     @line_magic
     def who(self, parameter_s=''):
         """Print all interactive variables, with some minimal formatting.
 
         If any arguments are given, only variables whose type matches one of
         these are printed.  For example::
 
           %who function str
 
         will only list functions and strings, excluding all other types of
         variables.  To find the proper type names, simply use type(var) at a
         command line to see how python prints type names.  For example:
 
         ::
 
           In [1]: type('hello')\\
           Out[1]: <type 'str'>
 
         indicates that the type name for strings is 'str'.
 
         ``%who`` always excludes executed names loaded through your configuration
         file and things which are internal to IPython.
 
         This is deliberate, as typically you may load many modules and the
         purpose of %who is to show you only what you've manually defined.
 
         Examples
         --------
 
         Define two variables and list them with who::
 
           In [1]: alpha = 123
 
           In [2]: beta = 'test'
 
           In [3]: %who
           alpha   beta
 
           In [4]: %who int
           alpha
 
           In [5]: %who str
           beta
         """
 
         varlist = self.who_ls(parameter_s)
         if not varlist:
             if parameter_s:
                 print 'No variables match your requested type.'
             else:
                 print 'Interactive namespace is empty.'
             return
 
         # if we have variables, move on...
         count = 0
         for i in varlist:
             print i+'\t',
             count += 1
             if count > 8:
                 count = 0
                 print
         print
 
     @skip_doctest
     @line_magic
     def whos(self, parameter_s=''):
         """Like %who, but gives some extra information about each variable.
 
         The same type filtering of %who can be applied here.
 
         For all variables, the type is printed. Additionally it prints:
 
           - For {},[],(): their length.
 
           - For numpy arrays, a summary with shape, number of
           elements, typecode and size in memory.
 
           - Everything else: a string representation, snipping their middle if
           too long.
 
         Examples
         --------
 
         Define two variables and list them with whos::
 
           In [1]: alpha = 123
 
           In [2]: beta = 'test'
 
           In [3]: %whos
           Variable   Type        Data/Info
           --------------------------------
           alpha      int         123
           beta       str         test
         """
 
         varnames = self.who_ls(parameter_s)
         if not varnames:
             if parameter_s:
                 print 'No variables match your requested type.'
             else:
                 print 'Interactive namespace is empty.'
             return
 
         # if we have variables, move on...
 
         # for these types, show len() instead of data:
         seq_types = ['dict', 'list', 'tuple']
 
         # for numpy arrays, display summary info
         ndarray_type = None
         if 'numpy' in sys.modules:
             try:
                 from numpy import ndarray
             except ImportError:
                 pass
             else:
                 ndarray_type = ndarray.__name__
 
         # Find all variable names and types so we can figure out column sizes
         def get_vars(i):
             return self.shell.user_ns[i]
 
         # some types are well known and can be shorter
         abbrevs = {'IPython.core.macro.Macro' : 'Macro'}
         def type_name(v):
             tn = type(v).__name__
             return abbrevs.get(tn,tn)
 
         varlist = map(get_vars,varnames)
 
         typelist = []
         for vv in varlist:
             tt = type_name(vv)
 
             if tt=='instance':
                 typelist.append( abbrevs.get(str(vv.__class__),
                                              str(vv.__class__)))
             else:
                 typelist.append(tt)
 
         # column labels and # of spaces as separator
         varlabel = 'Variable'
         typelabel = 'Type'
         datalabel = 'Data/Info'
         colsep = 3
         # variable format strings
         vformat    = "{0:<{varwidth}}{1:<{typewidth}}"
         aformat    = "%s: %s elems, type `%s`, %s bytes"
         # find the size of the columns to format the output nicely
         varwidth = max(max(map(len,varnames)), len(varlabel)) + colsep
         typewidth = max(max(map(len,typelist)), len(typelabel)) + colsep
         # table header
         print varlabel.ljust(varwidth) + typelabel.ljust(typewidth) + \
               ' '+datalabel+'\n' + '-'*(varwidth+typewidth+len(datalabel)+1)
         # and the table itself
         kb = 1024
         Mb = 1048576  # kb**2
         for vname,var,vtype in zip(varnames,varlist,typelist):
             print vformat.format(vname, vtype, varwidth=varwidth, typewidth=typewidth),
             if vtype in seq_types:
                 print "n="+str(len(var))
             elif vtype == ndarray_type:
                 vshape = str(var.shape).replace(',','').replace(' ','x')[1:-1]
                 if vtype==ndarray_type:
                     # numpy
                     vsize  = var.size
                     vbytes = vsize*var.itemsize
                     vdtype = var.dtype
 
                 if vbytes < 100000:
                     print aformat % (vshape, vsize, vdtype, vbytes)
                 else:
                     print aformat % (vshape, vsize, vdtype, vbytes),
                     if vbytes < Mb:
                         print '(%s kb)' % (vbytes/kb,)
                     else:
                         print '(%s Mb)' % (vbytes/Mb,)
             else:
                 try:
                     vstr = str(var)
                 except UnicodeEncodeError:
                     vstr = unicode(var).encode(DEFAULT_ENCODING,
                                                'backslashreplace')
                 except:
                     vstr = "<object with id %d (str() failed)>" % id(var)
                 vstr = vstr.replace('\n', '\\n')
                 if len(vstr) < 50:
                     print vstr
                 else:
                     print vstr[:25] + "<...>" + vstr[-25:]
 
     @line_magic
     def reset(self, parameter_s=''):
         """Resets the namespace by removing all names defined by the user, if
         called without arguments, or by removing some types of objects, such
         as everything currently in IPython's In[] and Out[] containers (see
         the parameters for details).
 
         Parameters
         ----------
         -f : force reset without asking for confirmation.
 
         -s : 'Soft' reset: Only clears your namespace, leaving history intact.
             References to objects may be kept. By default (without this option),
             we do a 'hard' reset, giving you a new session and removing all
             references to objects from the current session.
 
         in : reset input history
 
         out : reset output history
 
         dhist : reset directory history
 
         array : reset only variables that are NumPy arrays
 
         See Also
         --------
         magic_reset_selective : invoked as ``%reset_selective``
 
         Examples
         --------
         ::
 
           In [6]: a = 1
 
           In [7]: a
           Out[7]: 1
 
           In [8]: 'a' in _ip.user_ns
           Out[8]: True
 
           In [9]: %reset -f
 
           In [1]: 'a' in _ip.user_ns
           Out[1]: False
 
           In [2]: %reset -f in
           Flushing input history
 
           In [3]: %reset -f dhist in
           Flushing directory history
           Flushing input history
 
         Notes
         -----
         Calling this magic from clients that do not implement standard input,
         such as the ipython notebook interface, will reset the namespace
         without confirmation.
         """
         opts, args = self.parse_options(parameter_s,'sf', mode='list')
         if 'f' in opts:
             ans = True
         else:
             try:
                 ans = self.shell.ask_yes_no(
                 "Once deleted, variables cannot be recovered. Proceed (y/[n])?",
                 default='n')
             except StdinNotImplementedError:
                 ans = True
         if not ans:
             print 'Nothing done.'
             return
 
         if 's' in opts:                     # Soft reset
             user_ns = self.shell.user_ns
             for i in self.who_ls():
                 del(user_ns[i])
         elif len(args) == 0:                # Hard reset
             self.shell.reset(new_session = False)
 
         # reset in/out/dhist/array: previously extensinions/clearcmd.py
         ip = self.shell
         user_ns = self.shell.user_ns  # local lookup, heavily used
 
         for target in args:
             target = target.lower() # make matches case insensitive
             if target == 'out':
                 print "Flushing output cache (%d entries)" % len(user_ns['_oh'])
                 self.shell.displayhook.flush()
 
             elif target == 'in':
                 print "Flushing input history"
                 pc = self.shell.displayhook.prompt_count + 1
                 for n in range(1, pc):
                     key = '_i'+repr(n)
                     user_ns.pop(key,None)
                 user_ns.update(dict(_i=u'',_ii=u'',_iii=u''))
                 hm = ip.history_manager
                 # don't delete these, as %save and %macro depending on the
                 # length of these lists to be preserved
                 hm.input_hist_parsed[:] = [''] * pc
                 hm.input_hist_raw[:] = [''] * pc
                 # hm has internal machinery for _i,_ii,_iii, clear it out
                 hm._i = hm._ii = hm._iii = hm._i00 =  u''
 
             elif target == 'array':
                 # Support cleaning up numpy arrays
                 try:
                     from numpy import ndarray
                     # This must be done with items and not iteritems because
                     # we're going to modify the dict in-place.
                     for x,val in user_ns.items():
                         if isinstance(val,ndarray):
                             del user_ns[x]
                 except ImportError:
                     print "reset array only works if Numpy is available."
 
             elif target == 'dhist':
                 print "Flushing directory history"
                 del user_ns['_dh'][:]
 
             else:
                 print "Don't know how to reset ",
                 print target + ", please run `%reset?` for details"
 
         gc.collect()
 
     @line_magic
     def reset_selective(self, parameter_s=''):
         """Resets the namespace by removing names defined by the user.
 
         Input/Output history are left around in case you need them.
 
         %reset_selective [-f] regex
 
         No action is taken if regex is not included
 
         Options
           -f : force reset without asking for confirmation.
 
         See Also
         --------
         magic_reset : invoked as ``%reset``
 
         Examples
         --------
 
         We first fully reset the namespace so your output looks identical to
         this example for pedagogical reasons; in practice you do not need a
         full reset::
 
           In [1]: %reset -f
 
         Now, with a clean namespace we can make a few variables and use
         ``%reset_selective`` to only delete names that match our regexp::
 
           In [2]: a=1; b=2; c=3; b1m=4; b2m=5; b3m=6; b4m=7; b2s=8
 
           In [3]: who_ls
           Out[3]: ['a', 'b', 'b1m', 'b2m', 'b2s', 'b3m', 'b4m', 'c']
 
           In [4]: %reset_selective -f b[2-3]m
 
           In [5]: who_ls
           Out[5]: ['a', 'b', 'b1m', 'b2s', 'b4m', 'c']
 
           In [6]: %reset_selective -f d
 
           In [7]: who_ls
           Out[7]: ['a', 'b', 'b1m', 'b2s', 'b4m', 'c']
 
           In [8]: %reset_selective -f c
 
           In [9]: who_ls
           Out[9]: ['a', 'b', 'b1m', 'b2s', 'b4m']
 
           In [10]: %reset_selective -f b
 
           In [11]: who_ls
           Out[11]: ['a']
 
         Notes
         -----
         Calling this magic from clients that do not implement standard input,
         such as the ipython notebook interface, will reset the namespace
         without confirmation.
         """
 
         opts, regex = self.parse_options(parameter_s,'f')
 
         if opts.has_key('f'):
             ans = True
         else:
             try:
                 ans = self.shell.ask_yes_no(
                 "Once deleted, variables cannot be recovered. Proceed (y/[n])? ",
                 default='n')
             except StdinNotImplementedError:
                 ans = True
         if not ans:
             print 'Nothing done.'
             return
         user_ns = self.shell.user_ns
         if not regex:
             print 'No regex pattern specified. Nothing done.'
             return
         else:
             try:
                 m = re.compile(regex)
             except TypeError:
                 raise TypeError('regex must be a string or compiled pattern')
             for i in self.who_ls():
                 if m.search(i):
                     del(user_ns[i])
 
     @line_magic
     def xdel(self, parameter_s=''):
         """Delete a variable, trying to clear it from anywhere that
         IPython's machinery has references to it. By default, this uses
         the identity of the named object in the user namespace to remove
         references held under other names. The object is also removed
         from the output history.
 
         Options
           -n : Delete the specified name from all namespaces, without
           checking their identity.
         """
         opts, varname = self.parse_options(parameter_s,'n')
         try:
             self.shell.del_var(varname, ('n' in opts))
         except (NameError, ValueError) as e:
             print type(e).__name__ +": "+ str(e)

IPython/core/page.py

@@ -1,340 +1,340 b''
 # encoding: utf-8
 """
 Paging capabilities for IPython.core
 
 Authors:
 
 * Brian Granger
 * Fernando Perez
 
 Notes
 -----
 
 For now this uses ipapi, so it can't be in IPython.utils.  If we can get
 rid of that dependency, we could move it there.
 -----
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import re
 import sys
 import tempfile
 
 from io import UnsupportedOperation
 
 from IPython.core import ipapi
 from IPython.core.error import TryNext
 from IPython.utils.cursesimport import use_curses
 from IPython.utils.data import chop
 from IPython.utils import io
 from IPython.utils.process import system
 from IPython.utils.terminal import get_terminal_size
 
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 esc_re = re.compile(r"(\x1b[^m]+m)")
 
 def page_dumb(strng, start=0, screen_lines=25):
     """Very dumb 'pager' in Python, for when nothing else works.
 
     Only moves forward, same interface as page(), except for pager_cmd and
     mode."""
 
     out_ln  = strng.splitlines()[start:]
     screens = chop(out_ln,screen_lines-1)
     if len(screens) == 1:
         print >>io.stdout, os.linesep.join(screens[0])
     else:
         last_escape = ""
         for scr in screens[0:-1]:
             hunk = os.linesep.join(scr)
             print >>io.stdout, last_escape + hunk
             if not page_more():
                 return
             esc_list = esc_re.findall(hunk)
             if len(esc_list) > 0:
                 last_escape = esc_list[-1]
         print >>io.stdout, last_escape + os.linesep.join(screens[-1])
 
 def _detect_screen_size(use_curses, screen_lines_def):
     """Attempt to work out the number of lines on the screen.
     
     This is called by page(). It can raise an error (e.g. when run in the
     test suite), so it's separated out so it can easily be called in a try block.
     """
     TERM = os.environ.get('TERM',None)
     if (TERM=='xterm' or TERM=='xterm-color') and sys.platform != 'sunos5':
         local_use_curses = use_curses
     else:
         # curses causes problems on many terminals other than xterm, and
         # some termios calls lock up on Sun OS5.
         local_use_curses = False
     if local_use_curses:
         import termios
         import curses
         # There is a bug in curses, where *sometimes* it fails to properly
         # initialize, and then after the endwin() call is made, the
         # terminal is left in an unusable state.  Rather than trying to
         # check everytime for this (by requesting and comparing termios
         # flags each time), we just save the initial terminal state and
         # unconditionally reset it every time.  It's cheaper than making
         # the checks.
         term_flags = termios.tcgetattr(sys.stdout)
 
         # Curses modifies the stdout buffer size by default, which messes
         # up Python's normal stdout buffering.  This would manifest itself
         # to IPython users as delayed printing on stdout after having used
         # the pager.
         #
         # We can prevent this by manually setting the NCURSES_NO_SETBUF
         # environment variable.  For more details, see:
         # http://bugs.python.org/issue10144
         NCURSES_NO_SETBUF = os.environ.get('NCURSES_NO_SETBUF', None)
         os.environ['NCURSES_NO_SETBUF'] = ''
         
         # Proceed with curses initialization
         scr = curses.initscr()
         screen_lines_real,screen_cols = scr.getmaxyx()
         curses.endwin()
 
         # Restore environment
         if NCURSES_NO_SETBUF is None:
             del os.environ['NCURSES_NO_SETBUF']
         else:
             os.environ['NCURSES_NO_SETBUF'] = NCURSES_NO_SETBUF
             
         # Restore terminal state in case endwin() didn't.
         termios.tcsetattr(sys.stdout,termios.TCSANOW,term_flags)
         # Now we have what we needed: the screen size in rows/columns
         return screen_lines_real
         #print '***Screen size:',screen_lines_real,'lines x',\
         #screen_cols,'columns.' # dbg
     else:
         return screen_lines_def
 
 def page(strng, start=0, screen_lines=0, pager_cmd=None):
     """Print a string, piping through a pager after a certain length.
 
     The screen_lines parameter specifies the number of *usable* lines of your
     terminal screen (total lines minus lines you need to reserve to show other
     information).
 
     If you set screen_lines to a number <=0, page() will try to auto-determine
     your screen size and will only use up to (screen_size+screen_lines) for
     printing, paging after that. That is, if you want auto-detection but need
     to reserve the bottom 3 lines of the screen, use screen_lines = -3, and for
     auto-detection without any lines reserved simply use screen_lines = 0.
 
     If a string won't fit in the allowed lines, it is sent through the
     specified pager command. If none given, look for PAGER in the environment,
     and ultimately default to less.
 
     If no system pager works, the string is sent through a 'dumb pager'
     written in python, very simplistic.
     """
 
     # Some routines may auto-compute start offsets incorrectly and pass a
     # negative value.  Offset to 0 for robustness.
     start = max(0, start)
 
     # first, try the hook
     ip = ipapi.get()
     if ip:
         try:
             ip.hooks.show_in_pager(strng)
             return
         except TryNext:
             pass
 
     # Ugly kludge, but calling curses.initscr() flat out crashes in emacs
     TERM = os.environ.get('TERM','dumb')
     if TERM in ['dumb','emacs'] and os.name != 'nt':
         print strng
         return
     # chop off the topmost part of the string we don't want to see
     str_lines = strng.splitlines()[start:]
     str_toprint = os.linesep.join(str_lines)
     num_newlines = len(str_lines)
     len_str = len(str_toprint)
 
     # Dumb heuristics to guesstimate number of on-screen lines the string
     # takes.  Very basic, but good enough for docstrings in reasonable
     # terminals. If someone later feels like refining it, it's not hard.
     numlines = max(num_newlines,int(len_str/80)+1)
 
     screen_lines_def = get_terminal_size()[1]
 
     # auto-determine screen size
     if screen_lines <= 0:
         try:
             screen_lines += _detect_screen_size(use_curses, screen_lines_def)
         except (TypeError, UnsupportedOperation):
             print >>io.stdout, str_toprint
             return
 
     #print 'numlines',numlines,'screenlines',screen_lines  # dbg
     if numlines <= screen_lines :
         #print '*** normal print'  # dbg
         print >>io.stdout, str_toprint
     else:
         # Try to open pager and default to internal one if that fails.
         # All failure modes are tagged as 'retval=1', to match the return
         # value of a failed system command.  If any intermediate attempt
         # sets retval to 1, at the end we resort to our own page_dumb() pager.
         pager_cmd = get_pager_cmd(pager_cmd)
         pager_cmd += ' ' + get_pager_start(pager_cmd,start)
         if os.name == 'nt':
             if pager_cmd.startswith('type'):
                 # The default WinXP 'type' command is failing on complex strings.
                 retval = 1
             else:
                 tmpname = tempfile.mktemp('.txt')
                 tmpfile = open(tmpname,'wt')
                 tmpfile.write(strng)
                 tmpfile.close()
                 cmd = "%s < %s" % (pager_cmd,tmpname)
                 if os.system(cmd):
                   retval = 1
                 else:
                   retval = None
                 os.remove(tmpname)
         else:
             try:
                 retval = None
                 # if I use popen4, things hang. No idea why.
                 #pager,shell_out = os.popen4(pager_cmd)
                 pager = os.popen(pager_cmd,'w')
                 pager.write(strng)
                 pager.close()
                 retval = pager.close()  # success returns None
-            except IOError,msg:  # broken pipe when user quits
+            except IOError as msg:  # broken pipe when user quits
                 if msg.args == (32,'Broken pipe'):
                     retval = None
                 else:
                     retval = 1
             except OSError:
                 # Other strange problems, sometimes seen in Win2k/cygwin
                 retval = 1
         if retval is not None:
             page_dumb(strng,screen_lines=screen_lines)
 
 
 def page_file(fname, start=0, pager_cmd=None):
     """Page a file, using an optional pager command and starting line.
     """
 
     pager_cmd = get_pager_cmd(pager_cmd)
     pager_cmd += ' ' + get_pager_start(pager_cmd,start)
 
     try:
         if os.environ['TERM'] in ['emacs','dumb']:
             raise EnvironmentError
         system(pager_cmd + ' ' + fname)
     except:
         try:
             if start > 0:
                 start -= 1
             page(open(fname).read(),start)
         except:
             print 'Unable to show file',`fname`
 
 
 def get_pager_cmd(pager_cmd=None):
     """Return a pager command.
 
     Makes some attempts at finding an OS-correct one.
     """
     if os.name == 'posix':
         default_pager_cmd = 'less -r'  # -r for color control sequences
     elif os.name in ['nt','dos']:
         default_pager_cmd = 'type'
 
     if pager_cmd is None:
         try:
             pager_cmd = os.environ['PAGER']
         except:
             pager_cmd = default_pager_cmd
     return pager_cmd
 
 
 def get_pager_start(pager, start):
     """Return the string for paging files with an offset.
 
     This is the '+N' argument which less and more (under Unix) accept.
     """
 
     if pager in ['less','more']:
         if start:
             start_string = '+' + str(start)
         else:
             start_string = ''
     else:
         start_string = ''
     return start_string
 
 
 # (X)emacs on win32 doesn't like to be bypassed with msvcrt.getch()
 if os.name == 'nt' and os.environ.get('TERM','dumb') != 'emacs':
     import msvcrt
     def page_more():
         """ Smart pausing between pages
 
         @return:    True if need print more lines, False if quit
         """
         io.stdout.write('---Return to continue, q to quit--- ')
         ans = msvcrt.getch()
         if ans in ("q", "Q"):
             result = False
         else:
             result = True
         io.stdout.write("\b"*37 + " "*37 + "\b"*37)
         return result
 else:
     def page_more():
         ans = raw_input('---Return to continue, q to quit--- ')
         if ans.lower().startswith('q'):
             return False
         else:
             return True
 
 
 def snip_print(str,width = 75,print_full = 0,header = ''):
     """Print a string snipping the midsection to fit in width.
 
     print_full: mode control:
       - 0: only snip long strings
       - 1: send to page() directly.
       - 2: snip long strings and ask for full length viewing with page()
     Return 1 if snipping was necessary, 0 otherwise."""
 
     if print_full == 1:
         page(header+str)
         return 0
 
     print header,
     if len(str) < width:
         print str
         snip = 0
     else:
         whalf = int((width -5)/2)
         print str[:whalf] + ' <...> ' + str[-whalf:]
         snip = 1
     if snip and print_full == 2:
         if raw_input(header+' Snipped. View (y/n)? [N]').lower() == 'y':
             page(str)
     return snip
 

IPython/core/tests/test_run.py

@@ -1,250 +1,250 b''
 # encoding: utf-8
 """Tests for code execution (%run and related), which is particularly tricky.
 
 Because of how %run manages namespaces, and the fact that we are trying here to
 verify subtle object deletion and reference counting issues, the %run tests
 will be kept in this separate file.  This makes it easier to aggregate in one
 place the tricks needed to handle it; most other magics are much easier to test
 and we do so in a common test_magic file.
 """
 from __future__ import absolute_import
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import sys
 import tempfile
 
 import nose.tools as nt
 from nose import SkipTest
 
 from IPython.testing import decorators as dec
 from IPython.testing import tools as tt
 from IPython.utils import py3compat
 
 #-----------------------------------------------------------------------------
 # Test functions begin
 #-----------------------------------------------------------------------------
 
 def doctest_refbug():
     """Very nasty problem with references held by multiple runs of a script.
     See: https://github.com/ipython/ipython/issues/141
 
     In [1]: _ip.clear_main_mod_cache()
     # random
 
     In [2]: %run refbug
 
     In [3]: call_f()
     lowercased: hello
 
     In [4]: %run refbug
 
     In [5]: call_f()
     lowercased: hello
     lowercased: hello
     """
 
 
 def doctest_run_builtins():
     r"""Check that %run doesn't damage __builtins__.
 
     In [1]: import tempfile
 
     In [2]: bid1 = id(__builtins__)
 
     In [3]: fname = tempfile.mkstemp('.py')[1]
 
     In [3]: f = open(fname,'w')
 
     In [4]: dummy= f.write('pass\n')
 
     In [5]: f.flush()
 
     In [6]: t1 = type(__builtins__)
 
     In [7]: %run $fname
 
     In [7]: f.close()
 
     In [8]: bid2 = id(__builtins__)
 
     In [9]: t2 = type(__builtins__)
 
     In [10]: t1 == t2
     Out[10]: True
 
     In [10]: bid1 == bid2
     Out[10]: True
 
     In [12]: try:
        ....:     os.unlink(fname)
        ....: except:
        ....:     pass
        ....:
     """
 
 @py3compat.doctest_refactor_print
 def doctest_reset_del():
     """Test that resetting doesn't cause errors in __del__ methods.
 
     In [2]: class A(object):
        ...:     def __del__(self):
        ...:         print str("Hi")
        ...:
 
     In [3]: a = A()
 
     In [4]: get_ipython().reset()
     Hi
 
     In [5]: 1+1
     Out[5]: 2
     """
 
 # For some tests, it will be handy to organize them in a class with a common
 # setup that makes a temp file
 
 class TestMagicRunPass(tt.TempFileMixin):
 
     def setup(self):
         """Make a valid python temp file."""
         self.mktmp('pass\n')
         
     def run_tmpfile(self):
         _ip = get_ipython()
         # This fails on Windows if self.tmpfile.name has spaces or "~" in it.
         # See below and ticket https://bugs.launchpad.net/bugs/366353
         _ip.magic('run %s' % self.fname)
         
     def run_tmpfile_p(self):
         _ip = get_ipython()
         # This fails on Windows if self.tmpfile.name has spaces or "~" in it.
         # See below and ticket https://bugs.launchpad.net/bugs/366353
         _ip.magic('run -p %s' % self.fname)
 
     def test_builtins_id(self):
         """Check that %run doesn't damage __builtins__ """
         _ip = get_ipython()
         # Test that the id of __builtins__ is not modified by %run
         bid1 = id(_ip.user_ns['__builtins__'])
         self.run_tmpfile()
         bid2 = id(_ip.user_ns['__builtins__'])
         tt.assert_equals(bid1, bid2)
 
     def test_builtins_type(self):
         """Check that the type of __builtins__ doesn't change with %run.
 
         However, the above could pass if __builtins__ was already modified to
         be a dict (it should be a module) by a previous use of %run.  So we
         also check explicitly that it really is a module:
         """
         _ip = get_ipython()
         self.run_tmpfile()
         tt.assert_equals(type(_ip.user_ns['__builtins__']),type(sys))
 
     def test_prompts(self):
         """Test that prompts correctly generate after %run"""
         self.run_tmpfile()
         _ip = get_ipython()
         p2 = _ip.prompt_manager.render('in2').strip()
         nt.assert_equals(p2[:3], '...')
         
     def test_run_profile( self ):
         """Test that the option -p, which invokes the profiler, do not
         crash by invoking execfile"""
         _ip = get_ipython()
         self.run_tmpfile_p()
 
 
 class TestMagicRunSimple(tt.TempFileMixin):
 
     def test_simpledef(self):
         """Test that simple class definitions work."""
         src = ("class foo: pass\n"
                "def f(): return foo()")
         self.mktmp(src)
         _ip.magic('run %s' % self.fname)
         _ip.run_cell('t = isinstance(f(), foo)')
         nt.assert_true(_ip.user_ns['t'])
 
     def test_obj_del(self):
         """Test that object's __del__ methods are called on exit."""
         if sys.platform == 'win32':
             try:
                 import win32api
             except ImportError:
                 raise SkipTest("Test requires pywin32")
         src = ("class A(object):\n"
                "    def __del__(self):\n"
                "        print 'object A deleted'\n"
                "a = A()\n")
         self.mktmp(py3compat.doctest_refactor_print(src))
         if dec.module_not_available('sqlite3'):
             err = 'WARNING: IPython History requires SQLite, your history will not be saved\n'
         else:
             err = None
         tt.ipexec_validate(self.fname, 'object A deleted', err)
     
     @dec.skip_known_failure 
     def test_aggressive_namespace_cleanup(self):
         """Test that namespace cleanup is not too aggressive GH-238
 
         Returning from another run magic deletes the namespace"""
         # see ticket https://github.com/ipython/ipython/issues/238
         class secondtmp(tt.TempFileMixin): pass
         empty = secondtmp()
         empty.mktmp('')
         src = ("ip = get_ipython()\n"
                "for i in range(5):\n"
                "   try:\n"
                "       ip.magic('run %s')\n"
-               "   except NameError, e:\n"
+               "   except NameError as e:\n"
                "       print i;break\n" % empty.fname)
         self.mktmp(py3compat.doctest_refactor_print(src))
         _ip.magic('run %s' % self.fname)
         _ip.run_cell('ip == get_ipython()')
         tt.assert_equals(_ip.user_ns['i'], 5)
 
     @dec.skip_win32
     def test_tclass(self):
         mydir = os.path.dirname(__file__)
         tc = os.path.join(mydir, 'tclass')
         src = ("%%run '%s' C-first\n"
                "%%run '%s' C-second\n"
                "%%run '%s' C-third\n") % (tc, tc, tc)
         self.mktmp(src, '.ipy')
         out = """\
 ARGV 1-: ['C-first']
 ARGV 1-: ['C-second']
 tclass.py: deleting object: C-first
 ARGV 1-: ['C-third']
 tclass.py: deleting object: C-second
 tclass.py: deleting object: C-third
 """
         if dec.module_not_available('sqlite3'):
             err = 'WARNING: IPython History requires SQLite, your history will not be saved\n'
         else:
             err = None
         tt.ipexec_validate(self.fname, out, err)
 
     def test_run_i_after_reset(self):
         """Check that %run -i still works after %reset (gh-693)"""
         src = "yy = zz\n"
         self.mktmp(src)
         _ip.run_cell("zz = 23")
         _ip.magic('run -i %s' % self.fname)
         tt.assert_equals(_ip.user_ns['yy'], 23)
         _ip.magic('reset -f')
         _ip.run_cell("zz = 23")
         _ip.magic('run -i %s' % self.fname)
         tt.assert_equals(_ip.user_ns['yy'], 23)
     
     def test_unicode(self):
         """Check that files in odd encodings are accepted."""
         mydir = os.path.dirname(__file__)
         na = os.path.join(mydir, 'nonascii.py')
         _ip.magic('run "%s"' % na)
         tt.assert_equals(_ip.user_ns['u'], u'Ўт№Ф')

IPython/core/ultratb.py

@@ -1,1244 +1,1244 b''
 # -*- coding: utf-8 -*-
 """
 ultratb.py -- Spice up your tracebacks!
 
 * ColorTB
 I've always found it a bit hard to visually parse tracebacks in Python.  The
 ColorTB class is a solution to that problem.  It colors the different parts of a
 traceback in a manner similar to what you would expect from a syntax-highlighting
 text editor.
 
 Installation instructions for ColorTB:
     import sys,ultratb
     sys.excepthook = ultratb.ColorTB()
 
 * VerboseTB
 I've also included a port of Ka-Ping Yee's "cgitb.py" that produces all kinds
 of useful info when a traceback occurs.  Ping originally had it spit out HTML
 and intended it for CGI programmers, but why should they have all the fun?  I
 altered it to spit out colored text to the terminal.  It's a bit overwhelming,
 but kind of neat, and maybe useful for long-running programs that you believe
 are bug-free.  If a crash *does* occur in that type of program you want details.
 Give it a shot--you'll love it or you'll hate it.
 
 Note:
 
   The Verbose mode prints the variables currently visible where the exception
   happened (shortening their strings if too long). This can potentially be
   very slow, if you happen to have a huge data structure whose string
   representation is complex to compute. Your computer may appear to freeze for
   a while with cpu usage at 100%. If this occurs, you can cancel the traceback
   with Ctrl-C (maybe hitting it more than once).
 
   If you encounter this kind of situation often, you may want to use the
   Verbose_novars mode instead of the regular Verbose, which avoids formatting
   variables (but otherwise includes the information and context given by
   Verbose).
 
 
 Installation instructions for ColorTB:
     import sys,ultratb
     sys.excepthook = ultratb.VerboseTB()
 
 Note:  Much of the code in this module was lifted verbatim from the standard
 library module 'traceback.py' and Ka-Ping Yee's 'cgitb.py'.
 
 * Color schemes
 The colors are defined in the class TBTools through the use of the
 ColorSchemeTable class. Currently the following exist:
 
   - NoColor: allows all of this module to be used in any terminal (the color
   escapes are just dummy blank strings).
 
   - Linux: is meant to look good in a terminal like the Linux console (black
   or very dark background).
 
   - LightBG: similar to Linux but swaps dark/light colors to be more readable
   in light background terminals.
 
 You can implement other color schemes easily, the syntax is fairly
 self-explanatory. Please send back new schemes you develop to the author for
 possible inclusion in future releases.
 """
 
 #*****************************************************************************
 #       Copyright (C) 2001 Nathaniel Gray <[e-mail]>
 #       Copyright (C) 2001-2004 Fernando Perez <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 from __future__ import with_statement
 
 import inspect
 import keyword
 import linecache
 import os
 import pydoc
 import re
 import sys
 import time
 import tokenize
 import traceback
 import types
 
 try:                           # Python 2
     generate_tokens = tokenize.generate_tokens
 except AttributeError:         # Python 3
     generate_tokens = tokenize.tokenize
 
 # For purposes of monkeypatching inspect to fix a bug in it.
 from inspect import getsourcefile, getfile, getmodule,\
      ismodule, isclass, ismethod, isfunction, istraceback, isframe, iscode
 
 # IPython's own modules
 # Modified pdb which doesn't damage IPython's readline handling
 from IPython.core import debugger, ipapi
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.excolors import exception_colors
 from IPython.utils import PyColorize
 from IPython.utils import io
 from IPython.utils import py3compat
 from IPython.utils import pyfile
 from IPython.utils.data import uniq_stable
 from IPython.utils.warn import info, error
 
 # Globals
 # amount of space to put line numbers before verbose tracebacks
 INDENT_SIZE = 8
 
 # Default color scheme.  This is used, for example, by the traceback
 # formatter.  When running in an actual IPython instance, the user's rc.colors
 # value is used, but havinga module global makes this functionality available
 # to users of ultratb who are NOT running inside ipython.
 DEFAULT_SCHEME = 'NoColor'
 
 #---------------------------------------------------------------------------
 # Code begins
 
 # Utility functions
 def inspect_error():
     """Print a message about internal inspect errors.
 
     These are unfortunately quite common."""
 
     error('Internal Python error in the inspect module.\n'
           'Below is the traceback from this internal error.\n')
 
 
 # N.B. This function is a monkeypatch we are currently not applying.
 # It was written some time ago, to fix an apparent Python bug with
 # codeobj.co_firstlineno . Unfortunately, we don't know under what conditions
 # the bug occurred, so we can't tell if it has been fixed. If it reappears, we
 # will apply the monkeypatch again. Also, note that findsource() is not called
 # by our code at this time - we don't know if it was when the monkeypatch was
 # written, or if the monkeypatch is needed for some other code (like a debugger).
 # For the discussion about not applying it, see gh-1229. TK, Jan 2011.
 def findsource(object):
     """Return the entire source file and starting line number for an object.
 
     The argument may be a module, class, method, function, traceback, frame,
     or code object.  The source code is returned as a list of all the lines
     in the file and the line number indexes a line in that list.  An IOError
     is raised if the source code cannot be retrieved.
 
     FIXED version with which we monkeypatch the stdlib to work around a bug."""
 
     file = getsourcefile(object) or getfile(object)
     # If the object is a frame, then trying to get the globals dict from its
     # module won't work. Instead, the frame object itself has the globals
     # dictionary.
     globals_dict = None
     if inspect.isframe(object):
         # XXX: can this ever be false?
         globals_dict = object.f_globals
     else:
         module = getmodule(object, file)
         if module:
             globals_dict = module.__dict__
     lines = linecache.getlines(file, globals_dict)
     if not lines:
         raise IOError('could not get source code')
 
     if ismodule(object):
         return lines, 0
 
     if isclass(object):
         name = object.__name__
         pat = re.compile(r'^(\s*)class\s*' + name + r'\b')
         # make some effort to find the best matching class definition:
         # use the one with the least indentation, which is the one
         # that's most probably not inside a function definition.
         candidates = []
         for i in range(len(lines)):
             match = pat.match(lines[i])
             if match:
                 # if it's at toplevel, it's already the best one
                 if lines[i][0] == 'c':
                     return lines, i
                 # else add whitespace to candidate list
                 candidates.append((match.group(1), i))
         if candidates:
             # this will sort by whitespace, and by line number,
             # less whitespace first
             candidates.sort()
             return lines, candidates[0][1]
         else:
             raise IOError('could not find class definition')
 
     if ismethod(object):
         object = object.im_func
     if isfunction(object):
         object = object.func_code
     if istraceback(object):
         object = object.tb_frame
     if isframe(object):
         object = object.f_code
     if iscode(object):
         if not hasattr(object, 'co_firstlineno'):
             raise IOError('could not find function definition')
         pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
         pmatch = pat.match
         # fperez - fix: sometimes, co_firstlineno can give a number larger than
         # the length of lines, which causes an error.  Safeguard against that.
         lnum = min(object.co_firstlineno,len(lines))-1
         while lnum > 0:
             if pmatch(lines[lnum]): break
             lnum -= 1
 
         return lines, lnum
     raise IOError('could not find code object')
 
 # Not applying the monkeypatch - see above the function for details. TK, Jan 2012
 # Monkeypatch inspect to apply our bugfix.  This code only works with py25
 #if sys.version_info[:2] >= (2,5):
 #    inspect.findsource = findsource
 
 def fix_frame_records_filenames(records):
     """Try to fix the filenames in each record from inspect.getinnerframes().
 
     Particularly, modules loaded from within zip files have useless filenames
     attached to their code object, and inspect.getinnerframes() just uses it.
     """
     fixed_records = []
     for frame, filename, line_no, func_name, lines, index in records:
         # Look inside the frame's globals dictionary for __file__, which should
         # be better.
         better_fn = frame.f_globals.get('__file__', None)
         if isinstance(better_fn, str):
             # Check the type just in case someone did something weird with
             # __file__. It might also be None if the error occurred during
             # import.
             filename = better_fn
         fixed_records.append((frame, filename, line_no, func_name, lines, index))
     return fixed_records
 
 
 def _fixed_getinnerframes(etb, context=1,tb_offset=0):
     import linecache
     LNUM_POS, LINES_POS, INDEX_POS =  2, 4, 5
 
     records  = fix_frame_records_filenames(inspect.getinnerframes(etb, context))
 
     # If the error is at the console, don't build any context, since it would
     # otherwise produce 5 blank lines printed out (there is no file at the
     # console)
     rec_check = records[tb_offset:]
     try:
         rname = rec_check[0][1]
         if rname == '<ipython console>' or rname.endswith('<string>'):
             return rec_check
     except IndexError:
         pass
 
     aux = traceback.extract_tb(etb)
     assert len(records) == len(aux)
     for i, (file, lnum, _, _) in zip(range(len(records)), aux):
         maybeStart = lnum-1 - context//2
         start =  max(maybeStart, 0)
         end   = start + context
         lines = linecache.getlines(file)[start:end]
         buf = list(records[i])
         buf[LNUM_POS] = lnum
         buf[INDEX_POS] = lnum - 1 - start
         buf[LINES_POS] = lines
         records[i] = tuple(buf)
     return records[tb_offset:]
 
 # Helper function -- largely belongs to VerboseTB, but we need the same
 # functionality to produce a pseudo verbose TB for SyntaxErrors, so that they
 # can be recognized properly by ipython.el's py-traceback-line-re
 # (SyntaxErrors have to be treated specially because they have no traceback)
 
 _parser = PyColorize.Parser()
 
 def _format_traceback_lines(lnum, index, lines, Colors, lvals=None,scheme=None):
     numbers_width = INDENT_SIZE - 1
     res = []
     i = lnum - index
 
     # This lets us get fully syntax-highlighted tracebacks.
     if scheme is None:
         ipinst = ipapi.get()
         if ipinst is not None:
             scheme = ipinst.colors
         else:
             scheme = DEFAULT_SCHEME
 
     _line_format = _parser.format2
 
     for line in lines:
         # FIXME: we need to ensure the source is a pure string at this point,
         # else the coloring code makes a  royal mess.  This is in need of a
         # serious refactoring, so that all of the ultratb and PyColorize code
         # is unicode-safe.  So for now this is rather an ugly hack, but
         # necessary to at least have readable tracebacks. Improvements welcome!
         line = py3compat.cast_bytes_py2(line, 'utf-8')
 
         new_line, err = _line_format(line, 'str', scheme)
         if not err: line = new_line
 
         if i == lnum:
             # This is the line with the error
             pad = numbers_width - len(str(i))
             if pad >= 3:
                 marker = '-'*(pad-3) + '-> '
             elif pad == 2:
                 marker = '> '
             elif pad == 1:
                 marker = '>'
             else:
                 marker = ''
             num = marker + str(i)
             line = '%s%s%s %s%s' %(Colors.linenoEm, num,
                                    Colors.line, line, Colors.Normal)
         else:
             num = '%*s' % (numbers_width,i)
             line = '%s%s%s %s' %(Colors.lineno, num,
                                  Colors.Normal, line)
 
         res.append(line)
         if lvals and i == lnum:
             res.append(lvals + '\n')
         i = i + 1
     return res
 
 
 #---------------------------------------------------------------------------
 # Module classes
 class TBTools(object):
     """Basic tools used by all traceback printer classes."""
 
     # Number of frames to skip when reporting tracebacks
     tb_offset = 0
 
     def __init__(self, color_scheme='NoColor', call_pdb=False, ostream=None):
         # Whether to call the interactive pdb debugger after printing
         # tracebacks or not
         self.call_pdb = call_pdb
 
         # Output stream to write to.  Note that we store the original value in
         # a private attribute and then make the public ostream a property, so
         # that we can delay accessing io.stdout until runtime.  The way
         # things are written now, the io.stdout object is dynamically managed
         # so a reference to it should NEVER be stored statically.  This
         # property approach confines this detail to a single location, and all
         # subclasses can simply access self.ostream for writing.
         self._ostream = ostream
 
         # Create color table
         self.color_scheme_table = exception_colors()
 
         self.set_colors(color_scheme)
         self.old_scheme = color_scheme  # save initial value for toggles
 
         if call_pdb:
             self.pdb = debugger.Pdb(self.color_scheme_table.active_scheme_name)
         else:
             self.pdb = None
 
     def _get_ostream(self):
         """Output stream that exceptions are written to.
 
         Valid values are:
 
         - None: the default, which means that IPython will dynamically resolve
         to io.stdout.  This ensures compatibility with most tools, including
         Windows (where plain stdout doesn't recognize ANSI escapes).
 
         - Any object with 'write' and 'flush' attributes.
         """
         return io.stdout if self._ostream is None else self._ostream
 
     def _set_ostream(self, val):
         assert val is None or (hasattr(val, 'write') and hasattr(val, 'flush'))
         self._ostream = val
 
     ostream = property(_get_ostream, _set_ostream)
 
     def set_colors(self,*args,**kw):
         """Shorthand access to the color table scheme selector method."""
 
         # Set own color table
         self.color_scheme_table.set_active_scheme(*args,**kw)
         # for convenience, set Colors to the active scheme
         self.Colors = self.color_scheme_table.active_colors
         # Also set colors of debugger
         if hasattr(self,'pdb') and self.pdb is not None:
             self.pdb.set_colors(*args,**kw)
 
     def color_toggle(self):
         """Toggle between the currently active color scheme and NoColor."""
 
         if self.color_scheme_table.active_scheme_name == 'NoColor':
             self.color_scheme_table.set_active_scheme(self.old_scheme)
             self.Colors = self.color_scheme_table.active_colors
         else:
             self.old_scheme = self.color_scheme_table.active_scheme_name
             self.color_scheme_table.set_active_scheme('NoColor')
             self.Colors = self.color_scheme_table.active_colors
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return '\n'.join(stb)
 
     def text(self, etype, value, tb, tb_offset=None, context=5):
         """Return formatted traceback.
 
         Subclasses may override this if they add extra arguments.
         """
         tb_list = self.structured_traceback(etype, value, tb,
                                             tb_offset, context)
         return self.stb2text(tb_list)
 
     def structured_traceback(self, etype, evalue, tb, tb_offset=None,
                              context=5, mode=None):
         """Return a list of traceback frames.
 
         Must be implemented by each class.
         """
         raise NotImplementedError()
 
 
 #---------------------------------------------------------------------------
 class ListTB(TBTools):
     """Print traceback information from a traceback list, with optional color.
 
     Calling: requires 3 arguments:
       (etype, evalue, elist)
     as would be obtained by:
       etype, evalue, tb = sys.exc_info()
       if tb:
         elist = traceback.extract_tb(tb)
       else:
         elist = None
 
     It can thus be used by programs which need to process the traceback before
     printing (such as console replacements based on the code module from the
     standard library).
 
     Because they are meant to be called without a full traceback (only a
     list), instances of this class can't call the interactive pdb debugger."""
 
     def __init__(self,color_scheme = 'NoColor', call_pdb=False, ostream=None):
         TBTools.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                          ostream=ostream)
 
     def __call__(self, etype, value, elist):
         self.ostream.flush()
         self.ostream.write(self.text(etype, value, elist))
         self.ostream.write('\n')
 
     def structured_traceback(self, etype, value, elist, tb_offset=None,
                              context=5):
         """Return a color formatted string with the traceback info.
 
         Parameters
         ----------
         etype : exception type
           Type of the exception raised.
 
         value : object
           Data stored in the exception
 
         elist : list
           List of frames, see class docstring for details.
 
         tb_offset : int, optional
           Number of frames in the traceback to skip.  If not given, the
           instance value is used (set in constructor).
 
         context : int, optional
           Number of lines of context information to print.
 
         Returns
         -------
         String with formatted exception.
         """
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
         Colors = self.Colors
         out_list = []
         if elist:
 
             if tb_offset and len(elist) > tb_offset:
                 elist = elist[tb_offset:]
 
             out_list.append('Traceback %s(most recent call last)%s:' %
                                 (Colors.normalEm, Colors.Normal) + '\n')
             out_list.extend(self._format_list(elist))
         # The exception info should be a single entry in the list.
         lines = ''.join(self._format_exception_only(etype, value))
         out_list.append(lines)
 
         # Note: this code originally read:
 
         ## for line in lines[:-1]:
         ##     out_list.append(" "+line)
         ## out_list.append(lines[-1])
 
         # This means it was indenting everything but the last line by a little
         # bit.  I've disabled this for now, but if we see ugliness somewhre we
         # can restore it.
 
         return out_list
 
     def _format_list(self, extracted_list):
         """Format a list of traceback entry tuples for printing.
 
         Given a list of tuples as returned by extract_tb() or
         extract_stack(), return a list of strings ready for printing.
         Each string in the resulting list corresponds to the item with the
         same index in the argument list.  Each string ends in a newline;
         the strings may contain internal newlines as well, for those items
         whose source text line is not None.
 
         Lifted almost verbatim from traceback.py
         """
 
         Colors = self.Colors
         list = []
         for filename, lineno, name, line in extracted_list[:-1]:
             item = '  File %s"%s"%s, line %s%d%s, in %s%s%s\n' % \
                     (Colors.filename, filename, Colors.Normal,
                      Colors.lineno, lineno, Colors.Normal,
                      Colors.name, name, Colors.Normal)
             if line:
                 item += '    %s\n' % line.strip()
             list.append(item)
         # Emphasize the last entry
         filename, lineno, name, line = extracted_list[-1]
         item = '%s  File %s"%s"%s, line %s%d%s, in %s%s%s%s\n' % \
                 (Colors.normalEm,
                  Colors.filenameEm, filename, Colors.normalEm,
                  Colors.linenoEm, lineno, Colors.normalEm,
                  Colors.nameEm, name, Colors.normalEm,
                  Colors.Normal)
         if line:
             item += '%s    %s%s\n' % (Colors.line, line.strip(),
                                             Colors.Normal)
         list.append(item)
         #from pprint import pformat; print 'LISTTB', pformat(list) # dbg
         return list
 
     def _format_exception_only(self, etype, value):
         """Format the exception part of a traceback.
 
         The arguments are the exception type and value such as given by
         sys.exc_info()[:2]. The return value is a list of strings, each ending
         in a newline.  Normally, the list contains a single string; however,
         for SyntaxError exceptions, it contains several lines that (when
         printed) display detailed information about where the syntax error
         occurred.  The message indicating which exception occurred is the
         always last string in the list.
 
         Also lifted nearly verbatim from traceback.py
         """
 
         have_filedata = False
         Colors = self.Colors
         list = []
         stype = Colors.excName + etype.__name__ + Colors.Normal
         if value is None:
             # Not sure if this can still happen in Python 2.6 and above
             list.append( str(stype) + '\n')
         else:
             if etype is SyntaxError:
                 have_filedata = True
                 #print 'filename is',filename  # dbg
                 if not value.filename: value.filename = "<string>"
                 list.append('%s  File %s"%s"%s, line %s%d%s\n' % \
                         (Colors.normalEm,
                          Colors.filenameEm, value.filename, Colors.normalEm,
                          Colors.linenoEm, value.lineno, Colors.Normal  ))
                 if value.text is not None:
                     i = 0
                     while i < len(value.text) and value.text[i].isspace():
                         i += 1
                     list.append('%s    %s%s\n' % (Colors.line,
                                                   value.text.strip(),
                                                   Colors.Normal))
                     if value.offset is not None:
                         s = '    '
                         for c in value.text[i:value.offset-1]:
                             if c.isspace():
                                 s += c
                             else:
                                 s += ' '
                         list.append('%s%s^%s\n' % (Colors.caret, s,
                                                    Colors.Normal) )
 
             try:
                 s = value.msg
             except Exception:
                 s = self._some_str(value)
             if s:
                 list.append('%s%s:%s %s\n' % (str(stype), Colors.excName,
                                               Colors.Normal, s))
             else:
                 list.append('%s\n' % str(stype))
 
         # sync with user hooks
         if have_filedata:
             ipinst = ipapi.get()
             if ipinst is not None:
                 ipinst.hooks.synchronize_with_editor(value.filename, value.lineno, 0)
 
         return list
 
     def get_exception_only(self, etype, value):
         """Only print the exception type and message, without a traceback.
 
         Parameters
         ----------
         etype : exception type
         value : exception value
         """
         return ListTB.structured_traceback(self, etype, value, [])
 
 
     def show_exception_only(self, etype, evalue):
         """Only print the exception type and message, without a traceback.
 
         Parameters
         ----------
         etype : exception type
         value : exception value
         """
         # This method needs to use __call__ from *this* class, not the one from
         # a subclass whose signature or behavior may be different
         ostream = self.ostream
         ostream.flush()
         ostream.write('\n'.join(self.get_exception_only(etype, evalue)))
         ostream.flush()
 
     def _some_str(self, value):
         # Lifted from traceback.py
         try:
             return str(value)
         except:
             return '<unprintable %s object>' % type(value).__name__
 
 #----------------------------------------------------------------------------
 class VerboseTB(TBTools):
     """A port of Ka-Ping Yee's cgitb.py module that outputs color text instead
     of HTML.  Requires inspect and pydoc.  Crazy, man.
 
     Modified version which optionally strips the topmost entries from the
     traceback, to be used with alternate interpreters (because their own code
     would appear in the traceback)."""
 
     def __init__(self,color_scheme = 'Linux', call_pdb=False, ostream=None,
                  tb_offset=0, long_header=False, include_vars=True,
                  check_cache=None):
         """Specify traceback offset, headers and color scheme.
 
         Define how many frames to drop from the tracebacks. Calling it with
         tb_offset=1 allows use of this handler in interpreters which will have
         their own code at the top of the traceback (VerboseTB will first
         remove that frame before printing the traceback info)."""
         TBTools.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                          ostream=ostream)
         self.tb_offset = tb_offset
         self.long_header = long_header
         self.include_vars = include_vars
         # By default we use linecache.checkcache, but the user can provide a
         # different check_cache implementation.  This is used by the IPython
         # kernel to provide tracebacks for interactive code that is cached,
         # by a compiler instance that flushes the linecache but preserves its
         # own code cache.
         if check_cache is None:
             check_cache = linecache.checkcache
         self.check_cache = check_cache
 
     def structured_traceback(self, etype, evalue, etb, tb_offset=None,
                              context=5):
         """Return a nice text document describing the traceback."""
 
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
 
         # some locals
         try:
             etype = etype.__name__
         except AttributeError:
             pass
         Colors        = self.Colors   # just a shorthand + quicker name lookup
         ColorsNormal  = Colors.Normal  # used a lot
         col_scheme    = self.color_scheme_table.active_scheme_name
         indent        = ' '*INDENT_SIZE
         em_normal     = '%s\n%s%s' % (Colors.valEm, indent,ColorsNormal)
         undefined     = '%sundefined%s' % (Colors.em, ColorsNormal)
         exc = '%s%s%s' % (Colors.excName,etype,ColorsNormal)
 
         # some internal-use functions
         def text_repr(value):
             """Hopefully pretty robust repr equivalent."""
             # this is pretty horrible but should always return *something*
             try:
                 return pydoc.text.repr(value)
             except KeyboardInterrupt:
                 raise
             except:
                 try:
                     return repr(value)
                 except KeyboardInterrupt:
                     raise
                 except:
                     try:
                         # all still in an except block so we catch
                         # getattr raising
                         name = getattr(value, '__name__', None)
                         if name:
                             # ick, recursion
                             return text_repr(name)
                         klass = getattr(value, '__class__', None)
                         if klass:
                             return '%s instance' % text_repr(klass)
                     except KeyboardInterrupt:
                         raise
                     except:
                         return 'UNRECOVERABLE REPR FAILURE'
         def eqrepr(value, repr=text_repr): return '=%s' % repr(value)
         def nullrepr(value, repr=text_repr): return ''
 
         # meat of the code begins
         try:
             etype = etype.__name__
         except AttributeError:
             pass
 
         if self.long_header:
             # Header with the exception type, python version, and date
             pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
             date = time.ctime(time.time())
 
             head = '%s%s%s\n%s%s%s\n%s' % (Colors.topline, '-'*75, ColorsNormal,
                                            exc, ' '*(75-len(str(etype))-len(pyver)),
                                            pyver, date.rjust(75) )
             head += "\nA problem occured executing Python code.  Here is the sequence of function"\
                     "\ncalls leading up to the error, with the most recent (innermost) call last."
         else:
             # Simplified header
             head = '%s%s%s\n%s%s' % (Colors.topline, '-'*75, ColorsNormal,exc,
                                      'Traceback (most recent call last)'.\
                                                   rjust(75 - len(str(etype)) ) )
         frames = []
         # Flush cache before calling inspect.  This helps alleviate some of the
         # problems with python 2.3's inspect.py.
         ##self.check_cache()
         # Drop topmost frames if requested
         try:
             # Try the default getinnerframes and Alex's: Alex's fixes some
             # problems, but it generates empty tracebacks for console errors
             # (5 blanks lines) where none should be returned.
             #records = inspect.getinnerframes(etb, context)[tb_offset:]
             #print 'python records:', records # dbg
             records = _fixed_getinnerframes(etb, context, tb_offset)
             #print 'alex   records:', records # dbg
         except:
 
             # FIXME: I've been getting many crash reports from python 2.3
             # users, traceable to inspect.py.  If I can find a small test-case
             # to reproduce this, I should either write a better workaround or
             # file a bug report against inspect (if that's the real problem).
             # So far, I haven't been able to find an isolated example to
             # reproduce the problem.
             inspect_error()
             traceback.print_exc(file=self.ostream)
             info('\nUnfortunately, your original traceback can not be constructed.\n')
             return ''
 
         # build some color string templates outside these nested loops
         tpl_link       = '%s%%s%s' % (Colors.filenameEm,ColorsNormal)
         tpl_call       = 'in %s%%s%s%%s%s' % (Colors.vName, Colors.valEm,
                                               ColorsNormal)
         tpl_call_fail  = 'in %s%%s%s(***failed resolving arguments***)%s' % \
                          (Colors.vName, Colors.valEm, ColorsNormal)
         tpl_local_var  = '%s%%s%s' % (Colors.vName, ColorsNormal)
         tpl_global_var = '%sglobal%s %s%%s%s' % (Colors.em, ColorsNormal,
                                                  Colors.vName, ColorsNormal)
         tpl_name_val   = '%%s %s= %%s%s' % (Colors.valEm, ColorsNormal)
         tpl_line       = '%s%%s%s %%s' % (Colors.lineno, ColorsNormal)
         tpl_line_em    = '%s%%s%s %%s%s' % (Colors.linenoEm,Colors.line,
                                             ColorsNormal)
 
         # now, loop over all records printing context and info
         abspath = os.path.abspath
         for frame, file, lnum, func, lines, index in records:
             #print '*** record:',file,lnum,func,lines,index  # dbg
 
             if not file:
                 file = '?'
             elif not(file.startswith("<") and file.endswith(">")):
                 # Guess that filenames like <string> aren't real filenames, so
                 # don't call abspath on them.                    
                 try:
                     file = abspath(file)
                 except OSError:
                     # Not sure if this can still happen: abspath now works with
                     # file names like <string>
                     pass
 
             link = tpl_link % file
             args, varargs, varkw, locals = inspect.getargvalues(frame)
 
             if func == '?':
                 call = ''
             else:
                 # Decide whether to include variable details or not
                 var_repr = self.include_vars and eqrepr or nullrepr
                 try:
                     call = tpl_call % (func,inspect.formatargvalues(args,
                                                 varargs, varkw,
                                                 locals,formatvalue=var_repr))
                 except KeyError:
                     # This happens in situations like errors inside generator
                     # expressions, where local variables are listed in the
                     # line, but can't be extracted from the frame.  I'm not
                     # 100% sure this isn't actually a bug in inspect itself,
                     # but since there's no info for us to compute with, the
                     # best we can do is report the failure and move on.  Here
                     # we must *not* call any traceback construction again,
                     # because that would mess up use of %debug later on.  So we
                     # simply report the failure and move on.  The only
                     # limitation will be that this frame won't have locals
                     # listed in the call signature.  Quite subtle problem...
                     # I can't think of a good way to validate this in a unit
                     # test, but running a script consisting of:
                     #  dict( (k,v.strip()) for (k,v) in range(10) )
                     # will illustrate the error, if this exception catch is
                     # disabled.
                     call = tpl_call_fail % func
             
             # Don't attempt to tokenize binary files.
             if file.endswith(('.so', '.pyd', '.dll')):
                 frames.append('%s %s\n' % (link,call))
                 continue
             elif file.endswith(('.pyc','.pyo')):
                 # Look up the corresponding source file.
                 file = pyfile.source_from_cache(file)
 
             def linereader(file=file, lnum=[lnum], getline=linecache.getline):
                 line = getline(file, lnum[0])
                 lnum[0] += 1
                 return line
 
             # Build the list of names on this line of code where the exception
             # occurred.
             try:
                 names = []
                 name_cont = False
                 
                 for token_type, token, start, end, line in generate_tokens(linereader):
                     # build composite names
                     if token_type == tokenize.NAME and token not in keyword.kwlist:
                         if name_cont:
                             # Continuation of a dotted name
                             try:
                                 names[-1].append(token)
                             except IndexError:
                                 names.append([token])
                             name_cont = False
                         else:
                             # Regular new names.  We append everything, the caller
                             # will be responsible for pruning the list later.  It's
                             # very tricky to try to prune as we go, b/c composite
                             # names can fool us.  The pruning at the end is easy
                             # to do (or the caller can print a list with repeated
                             # names if so desired.
                             names.append([token])
                     elif token == '.':
                         name_cont = True
                     elif token_type == tokenize.NEWLINE:
                         break
                         
             except (IndexError, UnicodeDecodeError):
                 # signals exit of tokenizer
                 pass
-            except tokenize.TokenError,msg:
+            except tokenize.TokenError as msg:
                 _m = ("An unexpected error occurred while tokenizing input\n"
                       "The following traceback may be corrupted or invalid\n"
                       "The error message is: %s\n" % msg)
                 error(_m)
 
             # Join composite names (e.g. "dict.fromkeys")
             names = ['.'.join(n) for n in names]
             # prune names list of duplicates, but keep the right order
             unique_names = uniq_stable(names)
 
             # Start loop over vars
             lvals = []
             if self.include_vars:
                 for name_full in unique_names:
                     name_base = name_full.split('.',1)[0]
                     if name_base in frame.f_code.co_varnames:
                         if locals.has_key(name_base):
                             try:
                                 value = repr(eval(name_full,locals))
                             except:
                                 value = undefined
                         else:
                             value = undefined
                         name = tpl_local_var % name_full
                     else:
                         if frame.f_globals.has_key(name_base):
                             try:
                                 value = repr(eval(name_full,frame.f_globals))
                             except:
                                 value = undefined
                         else:
                             value = undefined
                         name = tpl_global_var % name_full
                     lvals.append(tpl_name_val % (name,value))
             if lvals:
                 lvals = '%s%s' % (indent,em_normal.join(lvals))
             else:
                 lvals = ''
 
             level = '%s %s\n' % (link,call)
 
             if index is None:
                 frames.append(level)
             else:
                 frames.append('%s%s' % (level,''.join(
                     _format_traceback_lines(lnum,index,lines,Colors,lvals,
                                             col_scheme))))
 
         # Get (safely) a string form of the exception info
         try:
             etype_str,evalue_str = map(str,(etype,evalue))
         except:
             # User exception is improperly defined.
             etype,evalue = str,sys.exc_info()[:2]
             etype_str,evalue_str = map(str,(etype,evalue))
         # ... and format it
         exception = ['%s%s%s: %s' % (Colors.excName, etype_str,
                                      ColorsNormal, evalue_str)]
         if (not py3compat.PY3) and type(evalue) is types.InstanceType:
             try:
                 names = [w for w in dir(evalue) if isinstance(w, basestring)]
             except:
                 # Every now and then, an object with funny inernals blows up
                 # when dir() is called on it.  We do the best we can to report
                 # the problem and continue
                 _m = '%sException reporting error (object with broken dir())%s:'
                 exception.append(_m % (Colors.excName,ColorsNormal))
                 etype_str,evalue_str = map(str,sys.exc_info()[:2])
                 exception.append('%s%s%s: %s' % (Colors.excName,etype_str,
                                      ColorsNormal, evalue_str))
                 names = []
             for name in names:
                 value = text_repr(getattr(evalue, name))
                 exception.append('\n%s%s = %s' % (indent, name, value))
 
         # vds: >>
         if records:
              filepath, lnum = records[-1][1:3]
              #print "file:", str(file), "linenb", str(lnum) # dbg
              filepath = os.path.abspath(filepath)
              ipinst = ipapi.get()
              if ipinst is not None:
                  ipinst.hooks.synchronize_with_editor(filepath, lnum, 0)
         # vds: <<
 
         # return all our info assembled as a single string
         # return '%s\n\n%s\n%s' % (head,'\n'.join(frames),''.join(exception[0]) )
         return [head] + frames + [''.join(exception[0])]
 
     def debugger(self,force=False):
         """Call up the pdb debugger if desired, always clean up the tb
         reference.
 
         Keywords:
 
           - force(False): by default, this routine checks the instance call_pdb
           flag and does not actually invoke the debugger if the flag is false.
           The 'force' option forces the debugger to activate even if the flag
           is false.
 
         If the call_pdb flag is set, the pdb interactive debugger is
         invoked. In all cases, the self.tb reference to the current traceback
         is deleted to prevent lingering references which hamper memory
         management.
 
         Note that each call to pdb() does an 'import readline', so if your app
         requires a special setup for the readline completers, you'll have to
         fix that by hand after invoking the exception handler."""
 
         if force or self.call_pdb:
             if self.pdb is None:
                 self.pdb = debugger.Pdb(
                     self.color_scheme_table.active_scheme_name)
             # the system displayhook may have changed, restore the original
             # for pdb
             display_trap = DisplayTrap(hook=sys.__displayhook__)
             with display_trap:
                 self.pdb.reset()
                 # Find the right frame so we don't pop up inside ipython itself
                 if hasattr(self,'tb') and self.tb is not None:
                     etb = self.tb
                 else:
                     etb = self.tb = sys.last_traceback
                 while self.tb is not None and self.tb.tb_next is not None:
                     self.tb = self.tb.tb_next
                 if etb and etb.tb_next:
                     etb = etb.tb_next
                 self.pdb.botframe = etb.tb_frame
                 self.pdb.interaction(self.tb.tb_frame, self.tb)
 
         if hasattr(self,'tb'):
             del self.tb
 
     def handler(self, info=None):
         (etype, evalue, etb) = info or sys.exc_info()
         self.tb = etb
         ostream = self.ostream
         ostream.flush()
         ostream.write(self.text(etype, evalue, etb))
         ostream.write('\n')
         ostream.flush()
 
     # Changed so an instance can just be called as VerboseTB_inst() and print
     # out the right info on its own.
     def __call__(self, etype=None, evalue=None, etb=None):
         """This hook can replace sys.excepthook (for Python 2.1 or higher)."""
         if etb is None:
             self.handler()
         else:
             self.handler((etype, evalue, etb))
         try:
             self.debugger()
         except KeyboardInterrupt:
             print "\nKeyboardInterrupt"
 
 #----------------------------------------------------------------------------
 class FormattedTB(VerboseTB, ListTB):
     """Subclass ListTB but allow calling with a traceback.
 
     It can thus be used as a sys.excepthook for Python > 2.1.
 
     Also adds 'Context' and 'Verbose' modes, not available in ListTB.
 
     Allows a tb_offset to be specified. This is useful for situations where
     one needs to remove a number of topmost frames from the traceback (such as
     occurs with python programs that themselves execute other python code,
     like Python shells).  """
 
     def __init__(self, mode='Plain', color_scheme='Linux', call_pdb=False,
                  ostream=None,
                  tb_offset=0, long_header=False, include_vars=False,
                  check_cache=None):
 
         # NEVER change the order of this list. Put new modes at the end:
         self.valid_modes = ['Plain','Context','Verbose']
         self.verbose_modes = self.valid_modes[1:3]
 
         VerboseTB.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                            ostream=ostream, tb_offset=tb_offset,
                            long_header=long_header, include_vars=include_vars,
                            check_cache=check_cache)
 
         # Different types of tracebacks are joined with different separators to
         # form a single string.  They are taken from this dict
         self._join_chars = dict(Plain='', Context='\n', Verbose='\n')
         # set_mode also sets the tb_join_char attribute
         self.set_mode(mode)
 
     def _extract_tb(self,tb):
         if tb:
             return traceback.extract_tb(tb)
         else:
             return None
 
     def structured_traceback(self, etype, value, tb, tb_offset=None, context=5):
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
         mode = self.mode
         if mode in self.verbose_modes:
             # Verbose modes need a full traceback
             return VerboseTB.structured_traceback(
                 self, etype, value, tb, tb_offset, context
             )
         else:
             # We must check the source cache because otherwise we can print
             # out-of-date source code.
             self.check_cache()
             # Now we can extract and format the exception
             elist = self._extract_tb(tb)
             return ListTB.structured_traceback(
                 self, etype, value, elist, tb_offset, context
             )
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return self.tb_join_char.join(stb)
 
 
     def set_mode(self,mode=None):
         """Switch to the desired mode.
 
         If mode is not specified, cycles through the available modes."""
 
         if not mode:
             new_idx = ( self.valid_modes.index(self.mode) + 1 ) % \
                       len(self.valid_modes)
             self.mode = self.valid_modes[new_idx]
         elif mode not in self.valid_modes:
             raise ValueError, 'Unrecognized mode in FormattedTB: <'+mode+'>\n'\
                   'Valid modes: '+str(self.valid_modes)
         else:
             self.mode = mode
         # include variable details only in 'Verbose' mode
         self.include_vars = (self.mode == self.valid_modes[2])
         # Set the join character for generating text tracebacks
         self.tb_join_char = self._join_chars[self.mode]
 
     # some convenient shorcuts
     def plain(self):
         self.set_mode(self.valid_modes[0])
 
     def context(self):
         self.set_mode(self.valid_modes[1])
 
     def verbose(self):
         self.set_mode(self.valid_modes[2])
 
 #----------------------------------------------------------------------------
 class AutoFormattedTB(FormattedTB):
     """A traceback printer which can be called on the fly.
 
     It will find out about exceptions by itself.
 
     A brief example:
 
     AutoTB = AutoFormattedTB(mode = 'Verbose',color_scheme='Linux')
     try:
       ...
     except:
       AutoTB()  # or AutoTB(out=logfile) where logfile is an open file object
     """
 
     def __call__(self,etype=None,evalue=None,etb=None,
                  out=None,tb_offset=None):
         """Print out a formatted exception traceback.
 
         Optional arguments:
           - out: an open file-like object to direct output to.
 
           - tb_offset: the number of frames to skip over in the stack, on a
           per-call basis (this overrides temporarily the instance's tb_offset
           given at initialization time.  """
 
 
         if out is None:
             out = self.ostream
         out.flush()
         out.write(self.text(etype, evalue, etb, tb_offset))
         out.write('\n')
         out.flush()
         # FIXME: we should remove the auto pdb behavior from here and leave
         # that to the clients.
         try:
             self.debugger()
         except KeyboardInterrupt:
             print "\nKeyboardInterrupt"
 
     def structured_traceback(self, etype=None, value=None, tb=None,
                              tb_offset=None, context=5):
         if etype is None:
             etype,value,tb = sys.exc_info()
         self.tb = tb
         return FormattedTB.structured_traceback(
             self, etype, value, tb, tb_offset, context)
 
 #---------------------------------------------------------------------------
 
 # A simple class to preserve Nathan's original functionality.
 class ColorTB(FormattedTB):
     """Shorthand to initialize a FormattedTB in Linux colors mode."""
     def __init__(self,color_scheme='Linux',call_pdb=0):
         FormattedTB.__init__(self,color_scheme=color_scheme,
                              call_pdb=call_pdb)
 
 
 class SyntaxTB(ListTB):
     """Extension which holds some state: the last exception value"""
 
     def __init__(self,color_scheme = 'NoColor'):
         ListTB.__init__(self,color_scheme)
         self.last_syntax_error = None
 
     def __call__(self, etype, value, elist):
         self.last_syntax_error = value
         ListTB.__call__(self,etype,value,elist)
 
     def clear_err_state(self):
         """Return the current error state and clear it"""
         e = self.last_syntax_error
         self.last_syntax_error = None
         return e
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return ''.join(stb)
 
 
 #----------------------------------------------------------------------------
 # module testing (minimal)
 if __name__ == "__main__":
     def spam(c, (d, e)):
         x = c + d
         y = c * d
         foo(x, y)
 
     def foo(a, b, bar=1):
         eggs(a, b + bar)
 
     def eggs(f, g, z=globals()):
         h = f + g
         i = f - g
         return h / i
 
     print ''
     print '*** Before ***'
     try:
         print spam(1, (2, 3))
     except:
         traceback.print_exc()
     print ''
 
     handler = ColorTB()
     print '*** ColorTB ***'
     try:
         print spam(1, (2, 3))
     except:
         apply(handler, sys.exc_info() )
     print ''
 
     handler = VerboseTB()
     print '*** VerboseTB ***'
     try:
         print spam(1, (2, 3))
     except:
         apply(handler, sys.exc_info() )
     print ''
 

IPython/deathrow/ibrowse.py

@@ -1,1767 +1,1767 b''
 # -*- coding: iso-8859-1 -*-
 
 import curses, fcntl, signal, struct, tty, textwrap, inspect
 
 from IPython.core import ipapi
 
 import astyle, ipipe
 
 
 # Python 2.3 compatibility
 try:
     set
 except NameError:
     import sets
     set = sets.Set
 
 # Python 2.3 compatibility
 try:
     sorted
 except NameError:
     from ipipe import sorted
 
 
 class UnassignedKeyError(Exception):
     """
     Exception that is used for reporting unassigned keys.
     """
 
 
 class UnknownCommandError(Exception):
     """
     Exception that is used for reporting unknown commands (this should never
     happen).
     """
 
 
 class CommandError(Exception):
     """
     Exception that is used for reporting that a command can't be executed.
     """
 
 
 class Keymap(dict):
     """
     Stores mapping of keys to commands.
     """
     def __init__(self):
         self._keymap = {}
 
     def __setitem__(self, key, command):
         if isinstance(key, str):
             for c in key:
                 dict.__setitem__(self, ord(c), command)
         else:
             dict.__setitem__(self, key, command)
 
     def __getitem__(self, key):
         if isinstance(key, str):
             key = ord(key)
         return dict.__getitem__(self, key)
 
     def __detitem__(self, key):
         if isinstance(key, str):
             key = ord(key)
         dict.__detitem__(self, key)
 
     def register(self, command, *keys):
         for key in keys:
             self[key] = command
 
     def get(self, key, default=None):
         if isinstance(key, str):
             key = ord(key)
         return dict.get(self, key, default)
 
     def findkey(self, command, default=ipipe.noitem):
         for (key, commandcandidate) in self.iteritems():
             if commandcandidate == command:
                 return key
         if default is ipipe.noitem:
             raise KeyError(command)
         return default
 
 
 class _BrowserCachedItem(object):
     # This is used internally by ``ibrowse`` to store a item together with its
     # marked status.
     __slots__ = ("item", "marked")
 
     def __init__(self, item):
         self.item = item
         self.marked = False
 
 
 class _BrowserHelp(object):
     style_header = astyle.Style.fromstr("yellow:black:bold")
     # This is used internally by ``ibrowse`` for displaying the help screen.
     def __init__(self, browser):
         self.browser = browser
 
     def __xrepr__(self, mode):
         yield (-1, True)
         if mode == "header" or mode == "footer":
             yield (astyle.style_default, "ibrowse help screen")
         else:
             yield (astyle.style_default, repr(self))
 
     def __iter__(self):
         # Get reverse key mapping
         allkeys = {}
         for (key, cmd) in self.browser.keymap.iteritems():
             allkeys.setdefault(cmd, []).append(key)
 
         fields = ("key", "description")
 
         commands = []
         for name in dir(self.browser):
             if name.startswith("cmd_"):
                 command = getattr(self.browser, name)
                 commands.append((inspect.getsourcelines(command)[-1], name[4:], command))
         commands.sort()
         commands = [(c[1], c[2]) for c in commands]
         for (i, (name, command)) in enumerate(commands):
             if i:
                 yield ipipe.Fields(fields, key="", description="")
 
             description = command.__doc__
             if description is None:
                 lines = []
             else:
                 lines = [l.strip() for l in description.splitlines() if l.strip()]
                 description = "\n".join(lines)
                 lines = textwrap.wrap(description, 60)
             keys = allkeys.get(name, [])
 
             yield ipipe.Fields(fields, key="", description=astyle.Text((self.style_header, name)))
             for i in xrange(max(len(keys), len(lines))):
                 try:
                     key = self.browser.keylabel(keys[i])
                 except IndexError:
                     key = ""
                 try:
                     line = lines[i]
                 except IndexError:
                     line = ""
                 yield ipipe.Fields(fields, key=key, description=line)
 
 
 class _BrowserLevel(object):
     # This is used internally to store the state (iterator, fetch items,
     # position of cursor and screen, etc.) of one browser level
     # An ``ibrowse`` object keeps multiple ``_BrowserLevel`` objects in
     # a stack.
     def __init__(self, browser, input, mainsizey, *attrs):
         self.browser = browser
         self.input = input
         self.header = [x for x in ipipe.xrepr(input, "header") if not isinstance(x[0], int)]
         # iterator for the input
         self.iterator = ipipe.xiter(input)
 
         # is the iterator exhausted?
         self.exhausted = False
 
         # attributes to be display (autodetected if empty)
         self.attrs = attrs
 
         # fetched items (+ marked flag)
         self.items = ipipe.deque()
 
         # Number of marked objects
         self.marked = 0
 
         # Vertical cursor position
         self.cury = 0
 
         # Horizontal cursor position
         self.curx = 0
 
         # Index of first data column
         self.datastartx = 0
 
         # Index of first data line
         self.datastarty = 0
 
         # height of the data display area
         self.mainsizey = mainsizey
 
         # width of the data display area (changes when scrolling)
         self.mainsizex = 0
 
         # Size of row number (changes when scrolling)
         self.numbersizex = 0
 
         # Attributes to display (in this order)
         self.displayattrs = []
 
         # index and attribute under the cursor
         self.displayattr = (None, ipipe.noitem)
 
         # Maps attributes to column widths
         self.colwidths = {}
 
         # Set of hidden attributes
         self.hiddenattrs = set()
 
         # This takes care of all the caches etc.
         self.moveto(0, 0, refresh=True)
 
     def fetch(self, count):
         # Try to fill ``self.items`` with at least ``count`` objects.
         have = len(self.items)
         while not self.exhausted and have < count:
             try:
                 item = self.iterator.next()
             except StopIteration:
                 self.exhausted = True
                 break
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except Exception, exc:
+            except Exception as exc:
                 have += 1
                 self.items.append(_BrowserCachedItem(exc))
                 self.exhausted = True
                 break
             else:
                 have += 1
                 self.items.append(_BrowserCachedItem(item))
 
     def calcdisplayattrs(self):
         # Calculate which attributes are available from the objects that are
         # currently visible on screen (and store it in ``self.displayattrs``)
 
         attrs = set()
         self.displayattrs = []
         if self.attrs:
             # If the browser object specifies a fixed list of attributes,
             # simply use it (removing hidden attributes).
             for attr in self.attrs:
                 attr = ipipe.upgradexattr(attr)
                 if attr not in attrs and attr not in self.hiddenattrs:
                     self.displayattrs.append(attr)
                     attrs.add(attr)
         else:
             endy = min(self.datastarty+self.mainsizey, len(self.items))
             for i in xrange(self.datastarty, endy):
                 for attr in ipipe.xattrs(self.items[i].item, "default"):
                     if attr not in attrs and attr not in self.hiddenattrs:
                         self.displayattrs.append(attr)
                         attrs.add(attr)
 
     def getrow(self, i):
         # Return a dictionary with the attributes for the object
         # ``self.items[i]``. Attribute names are taken from
         # ``self.displayattrs`` so ``calcdisplayattrs()`` must have been
         # called before.
         row = {}
         item = self.items[i].item
         for attr in self.displayattrs:
             try:
                 value = attr.value(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except Exception, exc:
+            except Exception as exc:
                 value = exc
             # only store attribute if it exists (or we got an exception)
             if value is not ipipe.noitem:
                 # remember alignment, length and colored text
                 row[attr] = ipipe.xformat(value, "cell", self.browser.maxattrlength)
         return row
 
     def calcwidths(self):
         # Recalculate the displayed fields and their widths.
         # ``calcdisplayattrs()'' must have been called and the cache
         # for attributes of the objects on screen (``self.displayrows``)
         # must have been filled. This sets ``self.colwidths`` which maps
         # attribute descriptors to widths.
         self.colwidths = {}
         for row in self.displayrows:
             for attr in self.displayattrs:
                 try:
                     length = row[attr][1]
                 except KeyError:
                     length = 0
                 # always add attribute to colwidths, even if it doesn't exist
                 if attr not in self.colwidths:
                     self.colwidths[attr] = len(attr.name())
                 newwidth = max(self.colwidths[attr], length)
                 self.colwidths[attr] = newwidth
 
         # How many characters do we need to paint the largest item number?
         self.numbersizex = len(str(self.datastarty+self.mainsizey-1))
         # How must space have we got to display data?
         self.mainsizex = self.browser.scrsizex-self.numbersizex-3
         # width of all columns
         self.datasizex = sum(self.colwidths.itervalues()) + len(self.colwidths)
 
     def calcdisplayattr(self):
         # Find out which attribute the cursor is on and store this
         # information in ``self.displayattr``.
         pos = 0
         for (i, attr) in enumerate(self.displayattrs):
             if pos+self.colwidths[attr] >= self.curx:
                 self.displayattr = (i, attr)
                 break
             pos += self.colwidths[attr]+1
         else:
             self.displayattr = (None, ipipe.noitem)
 
     def moveto(self, x, y, refresh=False):
         # Move the cursor to the position ``(x,y)`` (in data coordinates,
         # not in screen coordinates). If ``refresh`` is true, all cached
         # values will be recalculated (e.g. because the list has been
         # resorted, so screen positions etc. are no longer valid).
         olddatastarty = self.datastarty
         oldx = self.curx
         oldy = self.cury
         x = int(x+0.5)
         y = int(y+0.5)
         newx = x # remember where we wanted to move
         newy = y # remember where we wanted to move
 
         scrollbordery = min(self.browser.scrollbordery, self.mainsizey//2)
         scrollborderx = min(self.browser.scrollborderx, self.mainsizex//2)
 
         # Make sure that the cursor didn't leave the main area vertically
         if y < 0:
             y = 0
         # try to get enough items to fill the screen
         self.fetch(max(y+scrollbordery+1, self.mainsizey))
         if y >= len(self.items):
             y = max(0, len(self.items)-1)
 
         # Make sure that the cursor stays on screen vertically
         if y < self.datastarty+scrollbordery:
             self.datastarty = max(0, y-scrollbordery)
         elif y >= self.datastarty+self.mainsizey-scrollbordery:
             self.datastarty = max(0, min(y-self.mainsizey+scrollbordery+1,
                                          len(self.items)-self.mainsizey))
 
         if refresh: # Do we need to refresh the complete display?
             self.calcdisplayattrs()
             endy = min(self.datastarty+self.mainsizey, len(self.items))
             self.displayrows = map(self.getrow, xrange(self.datastarty, endy))
             self.calcwidths()
         # Did we scroll vertically => update displayrows
         # and various other attributes
         elif self.datastarty != olddatastarty:
             # Recalculate which attributes we have to display
             olddisplayattrs = self.displayattrs
             self.calcdisplayattrs()
             # If there are new attributes, recreate the cache
             if self.displayattrs != olddisplayattrs:
                 endy = min(self.datastarty+self.mainsizey, len(self.items))
                 self.displayrows = map(self.getrow, xrange(self.datastarty, endy))
             elif self.datastarty<olddatastarty: # we did scroll up
                 # drop rows from the end
                 del self.displayrows[self.datastarty-olddatastarty:]
                 # fetch new items
                 for i in xrange(min(olddatastarty, self.datastarty+self.mainsizey)-1,
                                 self.datastarty-1, -1):
                     try:
                         row = self.getrow(i)
                     except IndexError:
                         # we didn't have enough objects to fill the screen
                         break
                     self.displayrows.insert(0, row)
             else: # we did scroll down
                 # drop rows from the start
                 del self.displayrows[:self.datastarty-olddatastarty]
                 # fetch new items
                 for i in xrange(max(olddatastarty+self.mainsizey, self.datastarty),
                                 self.datastarty+self.mainsizey):
                     try:
                         row = self.getrow(i)
                     except IndexError:
                         # we didn't have enough objects to fill the screen
                         break
                     self.displayrows.append(row)
             self.calcwidths()
 
         # Make sure that the cursor didn't leave the data area horizontally
         if x < 0:
             x = 0
         elif x >= self.datasizex:
             x = max(0, self.datasizex-1)
 
         # Make sure that the cursor stays on screen horizontally
         if x < self.datastartx+scrollborderx:
             self.datastartx = max(0, x-scrollborderx)
         elif x >= self.datastartx+self.mainsizex-scrollborderx:
             self.datastartx = max(0, min(x-self.mainsizex+scrollborderx+1,
                                          self.datasizex-self.mainsizex))
 
         if x == oldx and y == oldy and (x != newx or y != newy): # couldn't move
             self.browser.beep()
         else:
             self.curx = x
             self.cury = y
             self.calcdisplayattr()
 
     def sort(self, key, reverse=False):
         """
         Sort the currently list of items using the key function ``key``. If
         ``reverse`` is true the sort order is reversed.
         """
         curitem = self.items[self.cury] # Remember where the cursor is now
 
         # Sort items
         def realkey(item):
             return key(item.item)
         self.items = ipipe.deque(sorted(self.items, key=realkey, reverse=reverse))
 
         # Find out where the object under the cursor went
         cury = self.cury
         for (i, item) in enumerate(self.items):
             if item is curitem:
                 cury = i
                 break
 
         self.moveto(self.curx, cury, refresh=True)
 
     def refresh(self):
         """
         Restart iterating the input.
         """
         self.iterator = ipipe.xiter(self.input)
         self.items.clear()
         self.exhausted = False
         self.datastartx = self.datastarty = 0
         self.moveto(0, 0, refresh=True)
 
     def refreshfind(self):
         """
         Restart iterating the input and go back to the same object as before
         (if it can be found in the new iterator).
         """
         try:
             oldobject = self.items[self.cury].item
         except IndexError:
             oldobject = ipipe.noitem
         self.iterator = ipipe.xiter(self.input)
         self.items.clear()
         self.exhausted = False
         while True:
             self.fetch(len(self.items)+1)
             if self.exhausted:
                 curses.beep()
                 self.datastartx = self.datastarty = 0
                 self.moveto(self.curx, 0, refresh=True)
                 break
             if self.items[-1].item == oldobject:
                 self.datastartx = self.datastarty = 0
                 self.moveto(self.curx, len(self.items)-1, refresh=True)
                 break
 
 
 class _CommandInput(object):
     keymap = Keymap()
     keymap.register("left", curses.KEY_LEFT)
     keymap.register("right", curses.KEY_RIGHT)
     keymap.register("home", curses.KEY_HOME, "\x01") # Ctrl-A
     keymap.register("end", curses.KEY_END, "\x05") # Ctrl-E
     # FIXME: What's happening here?
     keymap.register("backspace", curses.KEY_BACKSPACE, "\x08\x7f")
     keymap.register("delete", curses.KEY_DC)
     keymap.register("delend", 0x0b) # Ctrl-K
     keymap.register("execute", "\r\n")
     keymap.register("up", curses.KEY_UP)
     keymap.register("down", curses.KEY_DOWN)
     keymap.register("incsearchup", curses.KEY_PPAGE)
     keymap.register("incsearchdown", curses.KEY_NPAGE)
     keymap.register("exit", "\x18"), # Ctrl-X
 
     def __init__(self, prompt):
         self.prompt = prompt
         self.history = []
         self.maxhistory = 100
         self.input = ""
         self.curx = 0
         self.cury = -1 # blank line
 
     def start(self):
         self.input = ""
         self.curx = 0
         self.cury = -1 # blank line
 
     def handlekey(self, browser, key):
         cmdname = self.keymap.get(key, None)
         if cmdname is not None:
             cmdfunc = getattr(self, "cmd_%s" % cmdname, None)
             if cmdfunc is not None:
                 return cmdfunc(browser)
             curses.beep()
         elif key != -1:
             try:
                 char = chr(key)
             except ValueError:
                 curses.beep()
             else:
                 return self.handlechar(browser, char)
 
     def handlechar(self, browser, char):
         self.input = self.input[:self.curx] + char + self.input[self.curx:]
         self.curx += 1
         return True
 
     def dohistory(self):
         self.history.insert(0, self.input)
         del self.history[:-self.maxhistory]
 
     def cmd_backspace(self, browser):
         if self.curx:
             self.input = self.input[:self.curx-1] + self.input[self.curx:]
             self.curx -= 1
             return True
         else:
             curses.beep()
 
     def cmd_delete(self, browser):
         if self.curx<len(self.input):
             self.input = self.input[:self.curx] + self.input[self.curx+1:]
             return True
         else:
             curses.beep()
 
     def cmd_delend(self, browser):
         if self.curx<len(self.input):
             self.input = self.input[:self.curx]
             return True
 
     def cmd_left(self, browser):
         if self.curx:
             self.curx -= 1
             return True
         else:
             curses.beep()
 
     def cmd_right(self, browser):
         if self.curx < len(self.input):
             self.curx += 1
             return True
         else:
             curses.beep()
 
     def cmd_home(self, browser):
         if self.curx:
             self.curx = 0
             return True
         else:
             curses.beep()
 
     def cmd_end(self, browser):
         if self.curx < len(self.input):
             self.curx = len(self.input)
             return True
         else:
             curses.beep()
 
     def cmd_up(self, browser):
         if self.cury < len(self.history)-1:
             self.cury += 1
             self.input = self.history[self.cury]
             self.curx = len(self.input)
             return True
         else:
             curses.beep()
 
     def cmd_down(self, browser):
         if self.cury >= 0:
             self.cury -= 1
             if self.cury>=0:
                 self.input = self.history[self.cury]
             else:
                 self.input = ""
             self.curx = len(self.input)
             return True
         else:
             curses.beep()
 
     def cmd_incsearchup(self, browser):
         prefix = self.input[:self.curx]
         cury = self.cury
         while True:
             cury += 1
             if cury >= len(self.history):
                 break
             if self.history[cury].startswith(prefix):
                 self.input = self.history[cury]
                 self.cury = cury
                 return True
         curses.beep()
 
     def cmd_incsearchdown(self, browser):
         prefix = self.input[:self.curx]
         cury = self.cury
         while True:
             cury -= 1
             if cury <= 0:
                 break
             if self.history[cury].startswith(prefix):
                 self.input = self.history[self.cury]
                 self.cury = cury
                 return True
         curses.beep()
 
     def cmd_exit(self, browser):
         browser.mode = "default"
         return True
 
     def cmd_execute(self, browser):
         raise NotImplementedError
 
 
 class _CommandGoto(_CommandInput):
     def __init__(self):
         _CommandInput.__init__(self, "goto object #")
 
     def handlechar(self, browser, char):
         # Only accept digits
         if not "0" <= char <= "9":
             curses.beep()
         else:
             return _CommandInput.handlechar(self, browser, char)
 
     def cmd_execute(self, browser):
         level = browser.levels[-1]
         if self.input:
             self.dohistory()
             level.moveto(level.curx, int(self.input))
         browser.mode = "default"
         return True
 
 
 class _CommandFind(_CommandInput):
     def __init__(self):
         _CommandInput.__init__(self, "find expression")
 
     def cmd_execute(self, browser):
         level = browser.levels[-1]
         if self.input:
             self.dohistory()
             while True:
                 cury = level.cury
                 level.moveto(level.curx, cury+1)
                 if cury == level.cury:
                     curses.beep()
                     break # hit end
                 item = level.items[level.cury].item
                 try:
                     globals = ipipe.getglobals(None)
                     if eval(self.input, globals, ipipe.AttrNamespace(item)):
                         break # found something
                 except (KeyboardInterrupt, SystemExit):
                     raise
-                except Exception, exc:
+                except Exception as exc:
                     browser.report(exc)
                     curses.beep()
                     break  # break on error
         browser.mode = "default"
         return True
 
 
 class _CommandFindBackwards(_CommandInput):
     def __init__(self):
         _CommandInput.__init__(self, "find backwards expression")
 
     def cmd_execute(self, browser):
         level = browser.levels[-1]
         if self.input:
             self.dohistory()
             while level.cury:
                 level.moveto(level.curx, level.cury-1)
                 item = level.items[level.cury].item
                 try:
                     globals = ipipe.getglobals(None)
                     if eval(self.input, globals, ipipe.AttrNamespace(item)):
                         break # found something
                 except (KeyboardInterrupt, SystemExit):
                     raise
-                except Exception, exc:
+                except Exception as exc:
                     browser.report(exc)
                     curses.beep()
                     break # break on error
             else:
                 curses.beep()
         browser.mode = "default"
         return True
 
 
 class ibrowse(ipipe.Display):
     # Show this many lines from the previous screen when paging horizontally
     pageoverlapx = 1
 
     # Show this many lines from the previous screen when paging vertically
     pageoverlapy = 1
 
     # Start scrolling when the cursor is less than this number of columns
     # away from the left or right screen edge
     scrollborderx = 10
 
     # Start scrolling when the cursor is less than this number of lines
     # away from the top or bottom screen edge
     scrollbordery = 5
 
     # Accelerate by this factor when scrolling horizontally
     acceleratex = 1.05
 
     # Accelerate by this factor when scrolling vertically
     acceleratey = 1.05
 
     # The maximum horizontal scroll speed
     # (as a factor of the screen width (i.e. 0.5 == half a screen width)
     maxspeedx = 0.5
 
     # The maximum vertical scroll speed
     # (as a factor of the screen height (i.e. 0.5 == half a screen height)
     maxspeedy = 0.5
 
     # The maximum number of header lines for browser level
     # if the nesting is deeper, only the innermost levels are displayed
     maxheaders = 5
 
     # The approximate maximum length of a column entry
     maxattrlength = 200
 
     # Styles for various parts of the GUI
     style_objheadertext = astyle.Style.fromstr("white:black:bold|reverse")
     style_objheadernumber = astyle.Style.fromstr("white:blue:bold|reverse")
     style_objheaderobject = astyle.Style.fromstr("white:black:reverse")
     style_colheader = astyle.Style.fromstr("blue:white:reverse")
     style_colheaderhere = astyle.Style.fromstr("green:black:bold|reverse")
     style_colheadersep = astyle.Style.fromstr("blue:black:reverse")
     style_number = astyle.Style.fromstr("blue:white:reverse")
     style_numberhere = astyle.Style.fromstr("green:black:bold|reverse")
     style_sep = astyle.Style.fromstr("blue:black")
     style_data = astyle.Style.fromstr("white:black")
     style_datapad = astyle.Style.fromstr("blue:black:bold")
     style_footer = astyle.Style.fromstr("black:white")
     style_report = astyle.Style.fromstr("white:black")
 
     # Column separator in header
     headersepchar = "|"
 
     # Character for padding data cell entries
     datapadchar = "."
 
     # Column separator in data area
     datasepchar = "|"
 
     # Character to use for "empty" cell (i.e. for non-existing attributes)
     nodatachar = "-"
 
     # Prompts for modes that require keyboard input
     prompts = {
         "goto": _CommandGoto(),
         "find": _CommandFind(),
         "findbackwards": _CommandFindBackwards()
     }
 
     # Maps curses key codes to "function" names
     keymap = Keymap()
     keymap.register("quit", "q")
     keymap.register("up", curses.KEY_UP)
     keymap.register("down", curses.KEY_DOWN)
     keymap.register("pageup", curses.KEY_PPAGE)
     keymap.register("pagedown", curses.KEY_NPAGE)
     keymap.register("left", curses.KEY_LEFT)
     keymap.register("right", curses.KEY_RIGHT)
     keymap.register("home", curses.KEY_HOME, "\x01")
     keymap.register("end", curses.KEY_END, "\x05")
     keymap.register("prevattr", "<\x1b")
     keymap.register("nextattr", ">\t")
     keymap.register("pick", "p")
     keymap.register("pickattr", "P")
     keymap.register("pickallattrs", "C")
     keymap.register("pickmarked", "m")
     keymap.register("pickmarkedattr", "M")
     keymap.register("pickinput", "i")
     keymap.register("pickinputattr", "I")
     keymap.register("hideattr", "h")
     keymap.register("unhideattrs", "H")
     keymap.register("help", "?")
     keymap.register("enter", "\r\n")
     keymap.register("enterattr", "E")
     # FIXME: What's happening here?
     keymap.register("leave", curses.KEY_BACKSPACE, "x\x08\x7f")
     keymap.register("detail", "d")
     keymap.register("detailattr", "D")
     keymap.register("tooglemark", " ")
     keymap.register("markrange", "%")
     keymap.register("sortattrasc", "v")
     keymap.register("sortattrdesc", "V")
     keymap.register("goto", "g")
     keymap.register("find", "f")
     keymap.register("findbackwards", "b")
     keymap.register("refresh", "r")
     keymap.register("refreshfind", "R")
 
     def __init__(self, input=None, *attrs):
         """
         Create a new browser. If ``attrs`` is not empty, it is the list
         of attributes that will be displayed in the browser, otherwise
         these will be determined by the objects on screen.
         """
         ipipe.Display.__init__(self, input)
 
         self.attrs = attrs
 
         # Stack of browser levels
         self.levels = []
         # how many colums to scroll (Changes when accelerating)
         self.stepx = 1.
 
         # how many rows to scroll (Changes when accelerating)
         self.stepy = 1.
 
         # Beep on the edges of the data area? (Will be set to ``False``
         # once the cursor hits the edge of the screen, so we don't get
         # multiple beeps).
         self._dobeep = True
 
         # Cache for registered ``curses`` colors and styles.
         self._styles = {}
         self._colors = {}
         self._maxcolor = 1
 
         # How many header lines do we want to paint (the numbers of levels
         # we have, but with an upper bound)
         self._headerlines = 1
 
         # Index of first header line
         self._firstheaderline = 0
 
         # curses window
         self.scr = None
         # report in the footer line (error, executed command etc.)
         self._report = None
 
         # value to be returned to the caller (set by commands)
         self.returnvalue = None
 
         # The mode the browser is in
         # e.g. normal browsing or entering an argument for a command
         self.mode = "default"
 
         # set by the SIGWINCH signal handler
         self.resized = False
 
     def nextstepx(self, step):
         """
         Accelerate horizontally.
         """
         return max(1., min(step*self.acceleratex,
                            self.maxspeedx*self.levels[-1].mainsizex))
 
     def nextstepy(self, step):
         """
         Accelerate vertically.
         """
         return max(1., min(step*self.acceleratey,
                            self.maxspeedy*self.levels[-1].mainsizey))
 
     def getstyle(self, style):
         """
         Register the ``style`` with ``curses`` or get it from the cache,
         if it has been registered before.
         """
         try:
             return self._styles[style.fg, style.bg, style.attrs]
         except KeyError:
             attrs = 0
             for b in astyle.A2CURSES:
                 if style.attrs & b:
                     attrs |= astyle.A2CURSES[b]
             try:
                 color = self._colors[style.fg, style.bg]
             except KeyError:
                 curses.init_pair(
                     self._maxcolor,
                     astyle.COLOR2CURSES[style.fg],
                     astyle.COLOR2CURSES[style.bg]
                 )
                 color = curses.color_pair(self._maxcolor)
                 self._colors[style.fg, style.bg] = color
                 self._maxcolor += 1
             c = color | attrs
             self._styles[style.fg, style.bg, style.attrs] = c
             return c
 
     def addstr(self, y, x, begx, endx, text, style):
         """
         A version of ``curses.addstr()`` that can handle ``x`` coordinates
         that are outside the screen.
         """
         text2 = text[max(0, begx-x):max(0, endx-x)]
         if text2:
             self.scr.addstr(y, max(x, begx), text2, self.getstyle(style))
         return len(text)
 
     def addchr(self, y, x, begx, endx, c, l, style):
         x0 = max(x, begx)
         x1 = min(x+l, endx)
         if x1>x0:
             self.scr.addstr(y, x0, c*(x1-x0), self.getstyle(style))
         return l
 
     def _calcheaderlines(self, levels):
         # Calculate how many headerlines do we have to display, if we have
         # ``levels`` browser levels
         if levels is None:
             levels = len(self.levels)
         self._headerlines = min(self.maxheaders, levels)
         self._firstheaderline = levels-self._headerlines
 
     def getstylehere(self, style):
         """
         Return a style for displaying the original style ``style``
         in the row the cursor is on.
         """
         return astyle.Style(style.fg, astyle.COLOR_BLUE, style.attrs | astyle.A_BOLD)
 
     def report(self, msg):
         """
         Store the message ``msg`` for display below the footer line. This
         will be displayed as soon as the screen is redrawn.
         """
         self._report = msg
 
     def enter(self, item, *attrs):
         """
         Enter the object ``item``. If ``attrs`` is specified, it will be used
         as a fixed list of attributes to display.
         """
         if self.levels and item is self.levels[-1].input:
             curses.beep()
             self.report(CommandError("Recursion on input object"))
         else:
             oldlevels = len(self.levels)
             self._calcheaderlines(oldlevels+1)
             try:
                 level = _BrowserLevel(
                     self,
                     item,
                     self.scrsizey-1-self._headerlines-2,
                     *attrs
                 )
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except Exception, exc:
+            except Exception as exc:
                 if not self.levels:
                     raise
                 self._calcheaderlines(oldlevels)
                 curses.beep()
                 self.report(exc)
             else:
                 self.levels.append(level)
 
     def startkeyboardinput(self, mode):
         """
         Enter mode ``mode``, which requires keyboard input.
         """
         self.mode = mode
         self.prompts[mode].start()
 
     def keylabel(self, keycode):
         """
         Return a pretty name for the ``curses`` key ``keycode`` (used in the
         help screen and in reports about unassigned keys).
         """
         if keycode <= 0xff:
             specialsnames = {
                 ord("\n"): "RETURN",
                 ord(" "): "SPACE",
                 ord("\t"): "TAB",
                 ord("\x7f"): "DELETE",
                 ord("\x08"): "BACKSPACE",
             }
             if keycode in specialsnames:
                 return specialsnames[keycode]
             elif 0x00 < keycode < 0x20:
                 return "CTRL-%s" % chr(keycode + 64)
             return repr(chr(keycode))
         for name in dir(curses):
             if name.startswith("KEY_") and getattr(curses, name) == keycode:
                 return name
         return str(keycode)
 
     def beep(self, force=False):
         if force or self._dobeep:
             curses.beep()
             # don't beep again (as long as the same key is pressed)
             self._dobeep = False
 
     def cmd_up(self):
         """
         Move the cursor to the previous row.
         """
         level = self.levels[-1]
         self.report("up")
         level.moveto(level.curx, level.cury-self.stepy)
 
     def cmd_down(self):
         """
         Move the cursor to the next row.
         """
         level = self.levels[-1]
         self.report("down")
         level.moveto(level.curx, level.cury+self.stepy)
 
     def cmd_pageup(self):
         """
         Move the cursor up one page.
         """
         level = self.levels[-1]
         self.report("page up")
         level.moveto(level.curx, level.cury-level.mainsizey+self.pageoverlapy)
 
     def cmd_pagedown(self):
         """
         Move the cursor down one page.
         """
         level = self.levels[-1]
         self.report("page down")
         level.moveto(level.curx, level.cury+level.mainsizey-self.pageoverlapy)
 
     def cmd_left(self):
         """
         Move the cursor left.
         """
         level = self.levels[-1]
         self.report("left")
         level.moveto(level.curx-self.stepx, level.cury)
 
     def cmd_right(self):
         """
         Move the cursor right.
         """
         level = self.levels[-1]
         self.report("right")
         level.moveto(level.curx+self.stepx, level.cury)
 
     def cmd_home(self):
         """
         Move the cursor to the first column.
         """
         level = self.levels[-1]
         self.report("home")
         level.moveto(0, level.cury)
 
     def cmd_end(self):
         """
         Move the cursor to the last column.
         """
         level = self.levels[-1]
         self.report("end")
         level.moveto(level.datasizex+level.mainsizey-self.pageoverlapx, level.cury)
 
     def cmd_prevattr(self):
         """
         Move the cursor one attribute column to the left.
         """
         level = self.levels[-1]
         if level.displayattr[0] is None or level.displayattr[0] == 0:
             self.beep()
         else:
             self.report("prevattr")
             pos = 0
             for (i, attrname) in enumerate(level.displayattrs):
                 if i == level.displayattr[0]-1:
                     break
                 pos += level.colwidths[attrname] + 1
             level.moveto(pos, level.cury)
 
     def cmd_nextattr(self):
         """
         Move the cursor one attribute column to the right.
         """
         level = self.levels[-1]
         if level.displayattr[0] is None or level.displayattr[0] == len(level.displayattrs)-1:
             self.beep()
         else:
             self.report("nextattr")
             pos = 0
             for (i, attrname) in enumerate(level.displayattrs):
                 if i == level.displayattr[0]+1:
                     break
                 pos += level.colwidths[attrname] + 1
             level.moveto(pos, level.cury)
 
     def cmd_pick(self):
         """
         'Pick' the object under the cursor (i.e. the row the cursor is on).
         This leaves the browser and returns the picked object to the caller.
         (In IPython this object will be available as the ``_`` variable.)
         """
         level = self.levels[-1]
         self.returnvalue = level.items[level.cury].item
         return True
 
     def cmd_pickattr(self):
         """
         'Pick' the attribute under the cursor (i.e. the row/column the
         cursor is on).
         """
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no column under cursor"))
             return
         value = attr.value(level.items[level.cury].item)
         if value is ipipe.noitem:
             curses.beep()
             self.report(AttributeError(attr.name()))
         else:
             self.returnvalue = value
             return True
 
     def cmd_pickallattrs(self):
         """
         Pick' the complete column under the cursor (i.e. the attribute under
         the cursor) from all currently fetched objects. These attributes
         will be returned as a list.
         """
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no column under cursor"))
             return
         result = []
         for cache in level.items:
             value = attr.value(cache.item)
             if value is not ipipe.noitem:
                 result.append(value)
         self.returnvalue = result
         return True
 
     def cmd_pickmarked(self):
         """
         'Pick' marked objects. Marked objects will be returned as a list.
         """
         level = self.levels[-1]
         self.returnvalue = [cache.item for cache in level.items if cache.marked]
         return True
 
     def cmd_pickmarkedattr(self):
         """
         'Pick' the attribute under the cursor from all marked objects
         (This returns a list).
         """
 
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no column under cursor"))
             return
         result = []
         for cache in level.items:
             if cache.marked:
                 value = attr.value(cache.item)
                 if value is not ipipe.noitem:
                     result.append(value)
         self.returnvalue = result
         return True
 
     def cmd_pickinput(self):
         """
         Use the object under the cursor (i.e. the row the cursor is on) as
         the next input line. This leaves the browser and puts the picked object
         in the input.
         """
         level = self.levels[-1]
         value = level.items[level.cury].item
         self.returnvalue = None
         api = ipapi.get()
         api.set_next_input(str(value))
         return True
 
     def cmd_pickinputattr(self):
         """
         Use the attribute under the cursor i.e. the row/column the cursor is on)
         as the next input line. This leaves the browser and puts the picked
         object in the input.
         """
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no column under cursor"))
             return
         value = attr.value(level.items[level.cury].item)
         if value is ipipe.noitem:
             curses.beep()
             self.report(AttributeError(attr.name()))
         self.returnvalue = None
         api = ipapi.get()
         api.set_next_input(str(value))
         return True
 
     def cmd_markrange(self):
         """
         Mark all objects from the last marked object before the current cursor
         position to the cursor position.
         """
         level = self.levels[-1]
         self.report("markrange")
         start = None
         if level.items:
             for i in xrange(level.cury, -1, -1):
                 if level.items[i].marked:
                     start = i
                     break
         if start is None:
             self.report(CommandError("no mark before cursor"))
             curses.beep()
         else:
             for i in xrange(start, level.cury+1):
                 cache = level.items[i]
                 if not cache.marked:
                     cache.marked = True
                     level.marked += 1
 
     def cmd_enter(self):
         """
         Enter the object under the cursor. (what this mean depends on the object
         itself (i.e. how it implements iteration). This opens a new browser 'level'.
         """
         level = self.levels[-1]
         try:
             item = level.items[level.cury].item
         except IndexError:
             self.report(CommandError("No object"))
             curses.beep()
         else:
             self.report("entering object...")
             self.enter(item)
 
     def cmd_leave(self):
         """
         Leave the current browser level and go back to the previous one.
         """
         self.report("leave")
         if len(self.levels) > 1:
             self._calcheaderlines(len(self.levels)-1)
             self.levels.pop(-1)
         else:
             self.report(CommandError("This is the last level"))
             curses.beep()
 
     def cmd_enterattr(self):
         """
         Enter the attribute under the cursor.
         """
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no column under cursor"))
             return
         try:
             item = level.items[level.cury].item
         except IndexError:
             self.report(CommandError("No object"))
             curses.beep()
         else:
             value = attr.value(item)
             name = attr.name()
             if value is ipipe.noitem:
                 self.report(AttributeError(name))
             else:
                 self.report("entering object attribute %s..." % name)
                 self.enter(value)
 
     def cmd_detail(self):
         """
         Show a detail view of the object under the cursor. This shows the
         name, type, doc string and value of the object attributes (and it
         might show more attributes than in the list view, depending on
         the object).
         """
         level = self.levels[-1]
         try:
             item = level.items[level.cury].item
         except IndexError:
             self.report(CommandError("No object"))
             curses.beep()
         else:
             self.report("entering detail view for object...")
             attrs = [ipipe.AttributeDetail(item, attr) for attr in ipipe.xattrs(item, "detail")]
             self.enter(attrs)
 
     def cmd_detailattr(self):
         """
         Show a detail view of the attribute under the cursor.
         """
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no attribute"))
             return
         try:
             item = level.items[level.cury].item
         except IndexError:
             self.report(CommandError("No object"))
             curses.beep()
         else:
             try:
                 item = attr.value(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except Exception, exc:
+            except Exception as exc:
                 self.report(exc)
             else:
                 self.report("entering detail view for attribute %s..." % attr.name())
                 attrs = [ipipe.AttributeDetail(item, attr) for attr in ipipe.xattrs(item, "detail")]
                 self.enter(attrs)
 
     def cmd_tooglemark(self):
         """
         Mark/unmark the object under the cursor. Marked objects have a '!'
         after the row number).
         """
         level = self.levels[-1]
         self.report("toggle mark")
         try:
             item = level.items[level.cury]
         except IndexError: # no items?
             pass
         else:
             if item.marked:
                 item.marked = False
                 level.marked -= 1
             else:
                 item.marked = True
                 level.marked += 1
 
     def cmd_sortattrasc(self):
         """
         Sort the objects (in ascending order) using the attribute under
         the cursor as the sort key.
         """
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no column under cursor"))
             return
         self.report("sort by %s (ascending)" % attr.name())
         def key(item):
             try:
                 return attr.value(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
             except Exception:
                 return None
         level.sort(key)
 
     def cmd_sortattrdesc(self):
         """
         Sort the objects (in descending order) using the attribute under
         the cursor as the sort key.
         """
         level = self.levels[-1]
         attr = level.displayattr[1]
         if attr is ipipe.noitem:
             curses.beep()
             self.report(CommandError("no column under cursor"))
             return
         self.report("sort by %s (descending)" % attr.name())
         def key(item):
             try:
                 return attr.value(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
             except Exception:
                 return None
         level.sort(key, reverse=True)
 
     def cmd_hideattr(self):
         """
         Hide the attribute under the cursor.
         """
         level = self.levels[-1]
         if level.displayattr[0] is None:
             self.beep()
         else:
             self.report("hideattr")
             level.hiddenattrs.add(level.displayattr[1])
             level.moveto(level.curx, level.cury, refresh=True)
 
     def cmd_unhideattrs(self):
         """
         Make all attributes visible again.
         """
         level = self.levels[-1]
         self.report("unhideattrs")
         level.hiddenattrs.clear()
         level.moveto(level.curx, level.cury, refresh=True)
 
     def cmd_goto(self):
         """
         Jump to a row. The row number can be entered at the
         bottom of the screen.
         """
         self.startkeyboardinput("goto")
 
     def cmd_find(self):
         """
         Search forward for a row. The search condition can be entered at the
         bottom of the screen.
         """
         self.startkeyboardinput("find")
 
     def cmd_findbackwards(self):
         """
         Search backward for a row. The search condition can be entered at the
         bottom of the screen.
         """
         self.startkeyboardinput("findbackwards")
 
     def cmd_refresh(self):
         """
         Refreshes the display by restarting the iterator.
         """
         level = self.levels[-1]
         self.report("refresh")
         level.refresh()
 
     def cmd_refreshfind(self):
         """
         Refreshes the display by restarting the iterator and goes back to the
         same object the cursor was on before restarting (if this object can't be
         found the cursor jumps back to the first object).
         """
         level = self.levels[-1]
         self.report("refreshfind")
         level.refreshfind()
 
     def cmd_help(self):
         """
         Opens the help screen as a new browser level, describing keyboard
         shortcuts.
         """
         for level in self.levels:
             if isinstance(level.input, _BrowserHelp):
                 curses.beep()
                 self.report(CommandError("help already active"))
                 return
 
         self.enter(_BrowserHelp(self))
 
     def cmd_quit(self):
         """
         Quit the browser and return to the IPython prompt.
         """
         self.returnvalue = None
         return True
 
     def sigwinchhandler(self, signal, frame):
         self.resized = True
 
     def _dodisplay(self, scr):
         """
         This method is the workhorse of the browser. It handles screen
         drawing and the keyboard.
         """
         self.scr = scr
         curses.halfdelay(1)
         footery = 2
 
         keys = []
         for cmd in ("quit", "help"):
             key = self.keymap.findkey(cmd, None)
             if key is not None:
                 keys.append("%s=%s" % (self.keylabel(key), cmd))
         helpmsg = " | %s" % " ".join(keys)
 
         scr.clear()
         msg = "Fetching first batch of objects..."
         (self.scrsizey, self.scrsizex) = scr.getmaxyx()
         scr.addstr(self.scrsizey//2, (self.scrsizex-len(msg))//2, msg)
         scr.refresh()
 
         lastc = -1
 
         self.levels = []
         # enter the first level
         self.enter(self.input, *self.attrs)
 
         self._calcheaderlines(None)
 
         while True:
             level = self.levels[-1]
             (self.scrsizey, self.scrsizex) = scr.getmaxyx()
             level.mainsizey = self.scrsizey-1-self._headerlines-footery
 
             # Paint object header
             for i in xrange(self._firstheaderline, self._firstheaderline+self._headerlines):
                 lv = self.levels[i]
                 posx = 0
                 posy = i-self._firstheaderline
                 endx = self.scrsizex
                 if i: # not the first level
                     msg = " (%d/%d" % (self.levels[i-1].cury, len(self.levels[i-1].items))
                     if not self.levels[i-1].exhausted:
                         msg += "+"
                     msg += ") "
                     endx -= len(msg)+1
                 posx += self.addstr(posy, posx, 0, endx, " ibrowse #%d: " % i, self.style_objheadertext)
                 for (style, text) in lv.header:
                     posx += self.addstr(posy, posx, 0, endx, text, self.style_objheaderobject)
                     if posx >= endx:
                         break
                 if i:
                     posx += self.addstr(posy, posx, 0, self.scrsizex, msg, self.style_objheadernumber)
                 posx += self.addchr(posy, posx, 0, self.scrsizex, " ", self.scrsizex-posx, self.style_objheadernumber)
 
             if not level.items:
                 self.addchr(self._headerlines, 0, 0, self.scrsizex, " ", self.scrsizex, self.style_colheader)
                 self.addstr(self._headerlines+1, 0, 0, self.scrsizex, " <empty>", astyle.style_error)
                 scr.clrtobot()
             else:
                 # Paint column headers
                 scr.move(self._headerlines, 0)
                 scr.addstr(" %*s " % (level.numbersizex, "#"), self.getstyle(self.style_colheader))
                 scr.addstr(self.headersepchar, self.getstyle(self.style_colheadersep))
                 begx = level.numbersizex+3
                 posx = begx-level.datastartx
                 for attr in level.displayattrs:
                     attrname = attr.name()
                     cwidth = level.colwidths[attr]
                     header = attrname.ljust(cwidth)
                     if attr is level.displayattr[1]:
                         style = self.style_colheaderhere
                     else:
                         style = self.style_colheader
                     posx += self.addstr(self._headerlines, posx, begx, self.scrsizex, header, style)
                     posx += self.addstr(self._headerlines, posx, begx, self.scrsizex, self.headersepchar, self.style_colheadersep)
                     if posx >= self.scrsizex:
                         break
                 else:
                     scr.addstr(" "*(self.scrsizex-posx), self.getstyle(self.style_colheader))
 
                 # Paint rows
                 posy = self._headerlines+1+level.datastarty
                 for i in xrange(level.datastarty, min(level.datastarty+level.mainsizey, len(level.items))):
                     cache = level.items[i]
                     if i == level.cury:
                         style = self.style_numberhere
                     else:
                         style = self.style_number
 
                     posy = self._headerlines+1+i-level.datastarty
                     posx = begx-level.datastartx
 
                     scr.move(posy, 0)
                     scr.addstr(" %*d%s" % (level.numbersizex, i, " !"[cache.marked]), self.getstyle(style))
                     scr.addstr(self.headersepchar, self.getstyle(self.style_sep))
 
                     for attrname in level.displayattrs:
                         cwidth = level.colwidths[attrname]
                         try:
                             (align, length, parts) = level.displayrows[i-level.datastarty][attrname]
                         except KeyError:
                             align = 2
                             style = astyle.style_nodata
                             if i == level.cury:
                                 style = self.getstylehere(style)
                         padstyle = self.style_datapad
                         sepstyle = self.style_sep
                         if i == level.cury:
                             padstyle = self.getstylehere(padstyle)
                             sepstyle = self.getstylehere(sepstyle)
                         if align == 2:
                             posx += self.addchr(posy, posx, begx, self.scrsizex, self.nodatachar, cwidth, style)
                         else:
                             if align == 1:
                                 posx += self.addchr(posy, posx, begx, self.scrsizex, self.datapadchar, cwidth-length, padstyle)
                             elif align == 0:
                                 pad1 = (cwidth-length)//2
                                 pad2 = cwidth-length-len(pad1)
                                 posx += self.addchr(posy, posx, begx, self.scrsizex, self.datapadchar, pad1, padstyle)
                             for (style, text) in parts:
                                 if i == level.cury:
                                     style = self.getstylehere(style)
                                 posx += self.addstr(posy, posx, begx, self.scrsizex, text, style)
                                 if posx >= self.scrsizex:
                                     break
                             if align == -1:
                                 posx += self.addchr(posy, posx, begx, self.scrsizex, self.datapadchar, cwidth-length, padstyle)
                             elif align == 0:
                                 posx += self.addchr(posy, posx, begx, self.scrsizex, self.datapadchar, pad2, padstyle)
                         posx += self.addstr(posy, posx, begx, self.scrsizex, self.datasepchar, sepstyle)
                     else:
                         scr.clrtoeol()
 
                 # Add blank row headers for the rest of the screen
                 for posy in xrange(posy+1, self.scrsizey-2):
                     scr.addstr(posy, 0, " " * (level.numbersizex+2), self.getstyle(self.style_colheader))
                     scr.clrtoeol()
 
             posy = self.scrsizey-footery
             # Display footer
             scr.addstr(posy, 0, " "*self.scrsizex, self.getstyle(self.style_footer))
 
             if level.exhausted:
                 flag = ""
             else:
                 flag = "+"
 
             endx = self.scrsizex-len(helpmsg)-1
             scr.addstr(posy, endx, helpmsg, self.getstyle(self.style_footer))
 
             posx = 0
             msg = " %d%s objects (%d marked): " % (len(level.items), flag, level.marked)
             posx += self.addstr(posy, posx, 0, endx, msg, self.style_footer)
             try:
                 item = level.items[level.cury].item
             except IndexError: # empty
                 pass
             else:
                 for (nostyle, text) in ipipe.xrepr(item, "footer"):
                     if not isinstance(nostyle, int):
                         posx += self.addstr(posy, posx, 0, endx, text, self.style_footer)
                         if posx >= endx:
                             break
 
                 attrstyle = [(astyle.style_default, "no attribute")]
                 attr = level.displayattr[1]
                 if attr is not ipipe.noitem and not isinstance(attr, ipipe.SelfDescriptor):
                     posx += self.addstr(posy, posx, 0, endx, " | ", self.style_footer)
                     posx += self.addstr(posy, posx, 0, endx, attr.name(), self.style_footer)
                     posx += self.addstr(posy, posx, 0, endx, ": ", self.style_footer)
                     try:
                         value = attr.value(item)
                     except (SystemExit, KeyboardInterrupt):
                         raise
-                    except Exception, exc:
+                    except Exception as exc:
                         value = exc
                     if value is not ipipe.noitem:
                         attrstyle = ipipe.xrepr(value, "footer")
                     for (nostyle, text) in attrstyle:
                         if not isinstance(nostyle, int):
                             posx += self.addstr(posy, posx, 0, endx, text, self.style_footer)
                             if posx >= endx:
                                 break
 
             try:
                 # Display input prompt
                 if self.mode in self.prompts:
                     history = self.prompts[self.mode]
                     posx = 0
                     posy = self.scrsizey-1
                     posx += self.addstr(posy, posx, 0, endx, history.prompt, astyle.style_default)
                     posx += self.addstr(posy, posx, 0, endx, " [", astyle.style_default)
                     if history.cury==-1:
                         text = "new"
                     else:
                         text = str(history.cury+1)
                     posx += self.addstr(posy, posx, 0, endx, text, astyle.style_type_number)
                     if history.history:
                         posx += self.addstr(posy, posx, 0, endx, "/", astyle.style_default)
                         posx += self.addstr(posy, posx, 0, endx, str(len(history.history)), astyle.style_type_number)
                     posx += self.addstr(posy, posx, 0, endx, "]: ", astyle.style_default)
                     inputstartx = posx
                     posx += self.addstr(posy, posx, 0, endx, history.input, astyle.style_default)
                 # Display report
                 else:
                     if self._report is not None:
                         if isinstance(self._report, Exception):
                             style = self.getstyle(astyle.style_error)
                             if self._report.__class__.__module__ == "exceptions":
                                 msg = "%s: %s" % \
                                       (self._report.__class__.__name__, self._report)
                             else:
                                 msg = "%s.%s: %s" % \
                                       (self._report.__class__.__module__,
                                        self._report.__class__.__name__, self._report)
                         else:
                             style = self.getstyle(self.style_report)
                             msg = self._report
                         scr.addstr(self.scrsizey-1, 0, msg[:self.scrsizex], style)
                         self._report = None
                     else:
                         scr.move(self.scrsizey-1, 0)
             except curses.error:
                 # Protect against errors from writing to the last line
                 pass
             scr.clrtoeol()
 
             # Position cursor
             if self.mode in self.prompts:
                 history = self.prompts[self.mode]
                 scr.move(self.scrsizey-1, inputstartx+history.curx)
             else:
                 scr.move(
                     1+self._headerlines+level.cury-level.datastarty,
                     level.numbersizex+3+level.curx-level.datastartx
                 )
             scr.refresh()
 
             # Check keyboard
             while True:
                 c = scr.getch()
                 if self.resized:
                     size = fcntl.ioctl(0, tty.TIOCGWINSZ, "12345678")
                     size = struct.unpack("4H", size)
                     oldsize = scr.getmaxyx()
                     scr.erase()
                     curses.resize_term(size[0], size[1])
                     newsize = scr.getmaxyx()
                     scr.erase()
                     for l in self.levels:
                         l.mainsizey += newsize[0]-oldsize[0]
                         l.moveto(l.curx, l.cury, refresh=True)
                     scr.refresh()
                     self.resized = False
                     break # Redisplay
                 if self.mode in self.prompts:
                     if self.prompts[self.mode].handlekey(self, c):
                        break # Redisplay
                 else:
                     # if no key is pressed slow down and beep again
                     if c == -1:
                         self.stepx = 1.
                         self.stepy = 1.
                         self._dobeep = True
                     else:
                         # if a different key was pressed slow down and beep too
                         if c != lastc:
                             lastc = c
                             self.stepx = 1.
                             self.stepy = 1.
                             self._dobeep = True
                         cmdname = self.keymap.get(c, None)
                         if cmdname is None:
                             self.report(
                                 UnassignedKeyError("Unassigned key %s" %
                                                    self.keylabel(c)))
                         else:
                             cmdfunc = getattr(self, "cmd_%s" % cmdname, None)
                             if cmdfunc is None:
                                 self.report(
                                     UnknownCommandError("Unknown command %r" %
                                                         (cmdname,)))
                             elif cmdfunc():
                                 returnvalue = self.returnvalue
                                 self.returnvalue = None
                                 return returnvalue
                         self.stepx = self.nextstepx(self.stepx)
                         self.stepy = self.nextstepy(self.stepy)
                         curses.flushinp() # get rid of type ahead
                         break # Redisplay
         self.scr = None
 
     def display(self):
         if hasattr(curses, "resize_term") and hasattr(signal, 'SIGWINCH'):
             oldhandler = signal.signal(signal.SIGWINCH, self.sigwinchhandler)
             try:
                 return curses.wrapper(self._dodisplay)
             finally:
                 signal.signal(signal.SIGWINCH, oldhandler)
         else:
             return curses.wrapper(self._dodisplay)

IPython/deathrow/igrid.py

@@ -1,1126 +1,1126 b''
 # -*- coding: iso-8859-1 -*-
 
 import ipipe, os, webbrowser, urllib
 from IPython.core import ipapi
 import wx
 import wx.grid, wx.html
 
 try:
     sorted
 except NameError:
     from ipipe import sorted
 try:
     set
 except:
     from sets import Set as set
 
 
 __all__ = ["igrid"]
 
 
 help = """
 <?xml version='1.0' encoding='iso-8859-1'?>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html>
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
 <link rel="stylesheet" href="igrid_help.css" type="text/css" />
 <title>igrid help</title>
 </head>
 <body>
 <h1>igrid help</h1>
 
 
 <h2>Commands</h2>
 
 
 <h3>pick (P)</h3>
 <p>Pick the whole row (object is available as "_")</p>
 
 <h3>pickattr (Shift-P)</h3>
 <p>Pick the attribute under the cursor</p>
 
 <h3>pickallattrs (Shift-C)</h3>
 <p>Pick the complete column under the cursor (i.e. the attribute under the
 cursor) from all currently fetched objects. These attributes will be returned
 as a list.</p>
 
 <h3>pickinput (I)</h3>
 <p>Pick the current row as next input line in IPython. Additionally the row is stored as "_"</p>
 
 <h3>pickinputattr (Shift-I)</h3>
 <p>Pick the attribute under the cursor as next input line in IPython. Additionally the row is stored as "_"</p>
 
 <h3>enter (E)</h3>
 <p>Enter the object under the cursor. (what this mean depends on the object
 itself, i.e. how it implements iteration). This opens a new browser 'level'.</p>
 
 <h3>enterattr (Shift-E)</h3>
 <p>Enter the attribute under the cursor.</p>
 
 <h3>detail (D)</h3>
 <p>Show a detail view of the object under the cursor. This shows the name,
 type, doc string and value of the object attributes (and it might show more
 attributes than in the list view, depending on the object).</p>
 
 <h3>detailattr (Shift-D)</h3>
 <p>Show a detail view of the attribute under the cursor.</p>
 
 <h3>pickrows (M)</h3>
 <p>Pick multiple selected rows (M)</p>
 
 <h3>pickrowsattr (CTRL-M)</h3>
 <p>From multiple selected rows pick the cells matching the attribute the cursor is in (CTRL-M)</p>
 
 <h3>find (CTRL-F)</h3>
 <p>Find text</p>
 
 <h3>find_expression (CTRL-Shift-F)</h3>
 <p>Find entries matching an expression</p>
 
 <h3>find_next (F3)</h3>
 <p>Find next occurrence</p>
 
 <h3>find_previous (Shift-F3)</h3>
 <p>Find previous occurrence</p>
 
 <h3>sortattrasc (V)</h3>
 <p>Sort the objects (in ascending order) using the attribute under the cursor as the sort key.</p>
 
 <h3>sortattrdesc (Shift-V)</h3>
 <p>Sort the objects (in descending order) using the attribute under the cursor as the sort key.</p>
 
 <h3>refresh_once (R, F5)</h3>
 <p>Refreshes the display by restarting the iterator</p>
 
 <h3>refresh_every_second</h3>
 <p>Refreshes the display by restarting the iterator every second until stopped by stop_refresh.</p>
 
 <h3>refresh_interval</h3>
 <p>Refreshes the display by restarting the iterator every X ms (X is a custom interval set by the user) until stopped by stop_refresh.</p>
 
 <h3>stop_refresh</h3>
 <p>Stops all refresh timers.</p>
 
 <h3>leave (Backspace, DEL, X)</h3>
 <p>Close current tab (and all the tabs to the right of the current one).</h3>
 
 <h3>quit (ESC,Q)</h3>
 <p>Quit igrid and return to the IPython prompt.</p>
 
 
 <h2>Navigation</h2>
 
 
 <h3>Jump to the last column of the current row (END, CTRL-E, CTRL-Right)</h3>
 
 <h3>Jump to the first column of the current row (HOME, CTRL-A, CTRL-Left)</h3>
 
 <h3>Move the cursor one column to the left (&lt;)</h3>
 
 <h3>Move the cursor one column to the right (&gt;)</h3>
 
 <h3>Jump to the first row in the current column (CTRL-Up)</h3>
 
 <h3>Jump to the last row in the current column (CTRL-Down)</h3>
 
 </body>
 </html>
 
 """
 
 
 class IGridRenderer(wx.grid.PyGridCellRenderer):
     """
     This is a custom renderer for our IGridGrid
     """
     def __init__(self, table):
         self.maxchars = 200
         self.table = table
         self.colormap = (
             (  0,   0,   0),
             (174,   0,   0),
             (  0, 174,   0),
             (174, 174,   0),
             (  0,   0, 174),
             (174,   0, 174),
             (  0, 174, 174),
             ( 64,  64,  64)
         )
 
         wx.grid.PyGridCellRenderer.__init__(self)
 
     def _getvalue(self, row, col):
         try:
             value = self.table._displayattrs[col].value(self.table.items[row])
             (align, width, text) = ipipe.xformat(value, "cell", self.maxchars)
-        except Exception, exc:
+        except Exception as exc:
             (align, width, text) = ipipe.xformat(exc, "cell", self.maxchars)
         return (align, text)
 
     def GetBestSize(self, grid, attr, dc, row, col):
         text = grid.GetCellValue(row, col)
         (align, text) = self._getvalue(row, col)
         dc.SetFont(attr.GetFont())
         (w, h) = dc.GetTextExtent(str(text))
         return wx.Size(min(w+2, 600), h+2) # add border
 
     def Draw(self, grid, attr, dc, rect, row, col, isSelected):
         """
         Takes care of drawing everything in the cell; aligns the text
         """
         text = grid.GetCellValue(row, col)
         (align, text) = self._getvalue(row, col)
         if isSelected:
             bg = grid.GetSelectionBackground()
         else:
             bg = ["white", (240, 240, 240)][row%2]
         dc.SetTextBackground(bg)
         dc.SetBrush(wx.Brush(bg, wx.SOLID))
         dc.SetPen(wx.TRANSPARENT_PEN)
         dc.SetFont(attr.GetFont())
         dc.DrawRectangleRect(rect)
         dc.SetClippingRect(rect)
         # Format the text
         if align == -1: # left alignment
             (width, height) = dc.GetTextExtent(str(text))
             x = rect[0]+1
             y = rect[1]+0.5*(rect[3]-height)
 
             for (style, part) in text:
                 if isSelected:
                     fg = grid.GetSelectionForeground()
                 else:
                     fg = self.colormap[style.fg]
                 dc.SetTextForeground(fg)
                 (w, h) = dc.GetTextExtent(part)
                 dc.DrawText(part, x, y)
                 x += w
         elif align == 0: # center alignment
             (width, height) = dc.GetTextExtent(str(text))
             x = rect[0]+0.5*(rect[2]-width)
             y = rect[1]+0.5*(rect[3]-height)
             for (style, part) in text:
                 if isSelected:
                     fg = grid.GetSelectionForeground()
                 else:
                     fg = self.colormap[style.fg]
                 dc.SetTextForeground(fg)
                 (w, h) = dc.GetTextExtent(part)
                 dc.DrawText(part, x, y)
                 x += w
         else:  # right alignment
             (width, height) = dc.GetTextExtent(str(text))
             x = rect[0]+rect[2]-1
             y = rect[1]+0.5*(rect[3]-height)
             for (style, part) in reversed(text):
                 (w, h) = dc.GetTextExtent(part)
                 x -= w
                 if isSelected:
                     fg = grid.GetSelectionForeground()
                 else:
                     fg = self.colormap[style.fg]
                 dc.SetTextForeground(fg)
                 dc.DrawText(part, x, y)
         dc.DestroyClippingRegion()
 
     def Clone(self):
         return IGridRenderer(self.table)
 
 
 class IGridTable(wx.grid.PyGridTableBase):
     # The data table for the ``IGridGrid``. Some dirty tricks were used here:
     # ``GetValue()`` does not get any values (or at least it does not return
     # anything, accessing the values is done by the renderer)
     # but rather tries to fetch the objects which were requested into the table.
     # General behaviour is: Fetch the first X objects. If the user scrolls down
     # to the last object another bunch of X objects is fetched (if possible)
     def __init__(self, input, fontsize, *attrs):
         wx.grid.PyGridTableBase.__init__(self)
         self.input = input
         self.iterator = ipipe.xiter(input)
         self.items = []
         self.attrs = [ipipe.upgradexattr(attr) for attr in attrs]
         self._displayattrs = self.attrs[:]
         self._displayattrset = set(self.attrs)
         self.fontsize = fontsize
         self._fetch(1)
         self.timer = wx.Timer()
         self.timer.Bind(wx.EVT_TIMER, self.refresh_content)
 
     def GetAttr(self, *args):
         attr = wx.grid.GridCellAttr()
         attr.SetFont(wx.Font(self.fontsize, wx.TELETYPE, wx.NORMAL, wx.NORMAL))
         return attr
 
     def GetNumberRows(self):
         return len(self.items)
 
     def GetNumberCols(self):
         return len(self._displayattrs)
 
     def GetColLabelValue(self, col):
         if col < len(self._displayattrs):
             return self._displayattrs[col].name()
         else:
             return ""
 
     def GetRowLabelValue(self, row):
         return str(row)
 
     def IsEmptyCell(self, row, col):
         return False
 
     def _append(self, item):
         self.items.append(item)
         # Nothing to do if the set of attributes has been fixed by the user
         if not self.attrs:
             for attr in ipipe.xattrs(item):
                 attr = ipipe.upgradexattr(attr)
                 if attr not in self._displayattrset:
                     self._displayattrs.append(attr)
                     self._displayattrset.add(attr)
 
     def _fetch(self, count):
         # Try to fill ``self.items`` with at least ``count`` objects.
         have = len(self.items)
         while self.iterator is not None and have < count:
             try:
                 item = self.iterator.next()
             except StopIteration:
                 self.iterator = None
                 break
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except Exception, exc:
+            except Exception as exc:
                 have += 1
                 self._append(exc)
                 self.iterator = None
                 break
             else:
                 have += 1
                 self._append(item)
 
     def GetValue(self, row, col):
         # some kind of dummy-function: does not return anything but "";
         # (The value isn't use anyway)
         # its main task is to trigger the fetch of new objects
         sizing_needed = False
         had_cols = len(self._displayattrs)
         had_rows = len(self.items)
         if row == had_rows - 1 and self.iterator is not None:
             self._fetch(row + 20)
             sizing_needed = True
         have_rows = len(self.items)
         have_cols = len(self._displayattrs)
         if have_rows > had_rows:
             msg = wx.grid.GridTableMessage(self, wx.grid.GRIDTABLE_NOTIFY_ROWS_APPENDED, have_rows - had_rows)
             self.GetView().ProcessTableMessage(msg)
             sizing_needed = True
         if row >= have_rows:
             return ""
         if have_cols != had_cols:
             msg = wx.grid.GridTableMessage(self, wx.grid.GRIDTABLE_NOTIFY_COLS_APPENDED, have_cols - had_cols)
             self.GetView().ProcessTableMessage(msg)
             sizing_needed = True
         if sizing_needed:
             self.GetView().AutoSizeColumns(False)
         return ""
 
     def SetValue(self, row, col, value):
         pass
 
     def refresh_content(self, event):
         msg = wx.grid.GridTableMessage(self, wx.grid.GRIDTABLE_NOTIFY_ROWS_DELETED, 0, self.GetNumberRows())
         self.GetView().ProcessTableMessage(msg)
         self.iterator = ipipe.xiter(self.input)
         self.items = []
         self.attrs = [] # _append will calculate new displayattrs
         self._fetch(1) # fetch one...
         if self.items:
             msg = wx.grid.GridTableMessage(self, wx.grid.GRIDTABLE_NOTIFY_ROWS_APPENDED, 1)
             self.GetView().ProcessTableMessage(msg)
             self.GetValue(0, 0) # and trigger "fetch next 20"
             item = self.items[0]
             self.GetView().AutoSizeColumns(False)
             panel = self.GetView().GetParent()
             nb = panel.GetParent()
             current = nb.GetSelection()
             if nb.GetPage(current) == panel:
                 self.GetView().set_footer(item)
 
 class IGridGrid(wx.grid.Grid):
     # The actual grid
     # all methods for selecting/sorting/picking/... data are implemented here
     def __init__(self, panel, input, *attrs):
         wx.grid.Grid.__init__(self, panel)
         fontsize = 9
         self.input = input
         self.table = IGridTable(self.input, fontsize, *attrs)
         self.SetTable(self.table, True)
         self.SetSelectionMode(wx.grid.Grid.wxGridSelectRows)
         self.SetDefaultRenderer(IGridRenderer(self.table))
         self.EnableEditing(False)
         self.Bind(wx.EVT_KEY_DOWN, self.key_pressed)
         self.Bind(wx.grid.EVT_GRID_CELL_LEFT_DCLICK, self.cell_doubleclicked)
         self.Bind(wx.grid.EVT_GRID_CELL_LEFT_CLICK, self.cell_leftclicked)
         self.Bind(wx.grid.EVT_GRID_LABEL_LEFT_DCLICK, self.label_doubleclicked)
         self.Bind(wx.grid.EVT_GRID_LABEL_LEFT_CLICK, self.on_label_leftclick)
         self.Bind(wx.grid.EVT_GRID_RANGE_SELECT, self._on_selected_range)
         self.Bind(wx.grid.EVT_GRID_SELECT_CELL, self._on_selected_cell)
         self.current_selection = set()
         self.maxchars = 200
 
     def on_label_leftclick(self, event):
         event.Skip()
 
     def error_output(self, text):
         wx.Bell()
         frame = self.GetParent().GetParent().GetParent()
         frame.SetStatusText(str(text))
 
     def _on_selected_range(self, event):
         # Internal update to the selection tracking lists
         if event.Selecting():
             # adding to the list...
             self.current_selection.update(xrange(event.GetTopRow(), event.GetBottomRow()+1))
         else:
             # removal from list
             for index in xrange(event.GetTopRow(), event.GetBottomRow()+1):
                 self.current_selection.discard(index)
         event.Skip()
 
     def _on_selected_cell(self, event):
         # Internal update to the selection tracking list
         self.current_selection = set([event.GetRow()])
         event.Skip()
 
     def sort(self, key, reverse=False):
         """
         Sort the current list of items using the key function ``key``. If
         ``reverse`` is true the sort order is reversed.
         """
         row = self.GetGridCursorRow()
         col = self.GetGridCursorCol()
         curitem = self.table.items[row] # Remember where the cursor is now
         # Sort items
         def realkey(item):
             try:
                 return key(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
             except Exception:
                 return None
         try:
             self.table.items = ipipe.deque(sorted(self.table.items, key=realkey, reverse=reverse))
-        except TypeError, exc:
+        except TypeError as exc:
             self.error_output("Exception encountered: %s" % exc)
             return
         # Find out where the object under the cursor went
         for (i, item) in enumerate(self.table.items):
             if item is curitem:
                 self.SetGridCursor(i,col)
                 self.MakeCellVisible(i,col)
                 self.Refresh()
 
     def sortattrasc(self):
         """
         Sort in ascending order; sorting criteria is the current attribute
         """
         col = self.GetGridCursorCol()
         attr = self.table._displayattrs[col]
         frame = self.GetParent().GetParent().GetParent()
         if attr is ipipe.noitem:
             self.error_output("no column under cursor")
             return
         frame.SetStatusText("sort by %s (ascending)" % attr.name())
         def key(item):
             try:
                 return attr.value(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
             except Exception:
                 return None
         self.sort(key)
 
     def sortattrdesc(self):
         """
         Sort in descending order; sorting criteria is the current attribute
         """
         col = self.GetGridCursorCol()
         attr = self.table._displayattrs[col]
         frame = self.GetParent().GetParent().GetParent()
         if attr is ipipe.noitem:
             self.error_output("no column under cursor")
             return
         frame.SetStatusText("sort by %s (descending)" % attr.name())
         def key(item):
             try:
                 return attr.value(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
             except Exception:
                 return None
         self.sort(key, reverse=True)
 
     def label_doubleclicked(self, event):
         row = event.GetRow()
         col = event.GetCol()
         if col == -1:
             self.enter(row)
 
     def _getvalue(self, row, col):
         """
         Gets the text which is displayed at ``(row, col)``
         """
         try:
             value = self.table._displayattrs[col].value(self.table.items[row])
             (align, width, text) = ipipe.xformat(value, "cell", self.maxchars)
         except IndexError:
             raise IndexError
-        except Exception, exc:
+        except Exception as exc:
             (align, width, text) = ipipe.xformat(exc, "cell", self.maxchars)
         return text
 
     def searchexpression(self, searchexp, startrow=None, search_forward=True ):
         """
         Find by expression
         """
         frame = self.GetParent().GetParent().GetParent()
         if searchexp:
             if search_forward:
                 if not startrow:
                     row = self.GetGridCursorRow()+1
                 else:
                     row = startrow + 1
                 while True:
                     try:
                         foo = self.table.GetValue(row, 0)
                         item = self.table.items[row]
                         try:
                             globals = ipipe.getglobals(None)
                             if eval(searchexp, globals, ipipe.AttrNamespace(item)):
                                 self.SetGridCursor(row, 0) # found something
                                 self.MakeCellVisible(row, 0)
                                 break
                         except (KeyboardInterrupt, SystemExit):
                             raise
-                        except Exception, exc:
+                        except Exception as exc:
                             frame.SetStatusText(str(exc))
                             wx.Bell()
                             break  # break on error
                     except IndexError:
                         return
                     row += 1
             else:
                 if not startrow:
                     row = self.GetGridCursorRow() - 1
                 else:
                     row = startrow - 1
                 while True:
                     try:
                         foo = self.table.GetValue(row, 0)
                         item = self.table.items[row]
                         try:
                             globals = ipipe.getglobals(None)
                             if eval(searchexp, globals, ipipe.AttrNamespace(item)):
                                 self.SetGridCursor(row, 0) # found something
                                 self.MakeCellVisible(row, 0)
                                 break
                         except (KeyboardInterrupt, SystemExit):
                             raise
-                        except Exception, exc:
+                        except Exception as exc:
                             frame.SetStatusText(str(exc))
                             wx.Bell()
                             break  # break on error
                     except IndexError:
                         return
                     row -= 1
 
 
     def search(self, searchtext, startrow=None, startcol=None, search_forward=True):
         """
         search for ``searchtext``, starting in ``(startrow, startcol)``;
         if ``search_forward`` is true the direction is "forward"
         """
         searchtext = searchtext.lower()
         if search_forward:
             if startrow is not None and startcol is not None:
                 row = startrow
             else:
                 startcol = self.GetGridCursorCol() + 1
                 row = self.GetGridCursorRow()
                 if startcol >= self.GetNumberCols():
                     startcol = 0
                     row += 1
             while True:
                 for col in xrange(startcol, self.table.GetNumberCols()):
                     try:
                         foo = self.table.GetValue(row, col)
                         text = self._getvalue(row, col)
                         if searchtext in text.string().lower():
                             self.SetGridCursor(row, col)
                             self.MakeCellVisible(row, col)
                             return
                     except IndexError:
                         return
                 startcol = 0
                 row += 1
         else:
             if startrow is not None and startcol is not None:
                 row = startrow
             else:
                 startcol = self.GetGridCursorCol() - 1
                 row = self.GetGridCursorRow()
                 if startcol < 0:
                     startcol = self.GetNumberCols() - 1
                     row -= 1
             while True:
                 for col in xrange(startcol, -1, -1):
                     try:
                         foo = self.table.GetValue(row, col)
                         text = self._getvalue(row, col)
                         if searchtext in text.string().lower():
                             self.SetGridCursor(row, col)
                             self.MakeCellVisible(row, col)
                             return
                     except IndexError:
                         return
                 startcol = self.table.GetNumberCols()-1
                 row -= 1
 
     def key_pressed(self, event):
         """
         Maps pressed keys to functions
         """
         frame = self.GetParent().GetParent().GetParent()
         frame.SetStatusText("")
         sh = event.ShiftDown()
         ctrl = event.ControlDown()
 
         keycode = event.GetKeyCode()
         if keycode == ord("P"):
             row = self.GetGridCursorRow()
             if sh:
                 col = self.GetGridCursorCol()
                 self.pickattr(row, col)
             else:
                 self.pick(row)
         elif keycode == ord("M"):
             if ctrl:
                 col = self.GetGridCursorCol()
                 self.pickrowsattr(sorted(self.current_selection), col)
             else:
                 self.pickrows(sorted(self.current_selection))
         elif keycode in (wx.WXK_BACK, wx.WXK_DELETE, ord("X")) and not (ctrl or sh):
             self.delete_current_notebook()
         elif keycode in (ord("E"), ord("\r")):
             row = self.GetGridCursorRow()
             if sh:
                 col = self.GetGridCursorCol()
                 self.enterattr(row, col)
             else:
                 self.enter(row)
         elif keycode == ord("E") and ctrl:
             row = self.GetGridCursorRow()
             self.SetGridCursor(row, self.GetNumberCols()-1)
         elif keycode == wx.WXK_HOME or (keycode == ord("A") and ctrl):
             row = self.GetGridCursorRow()
             self.SetGridCursor(row, 0)
         elif keycode == ord("C") and sh:
             col = self.GetGridCursorCol()
             attr = self.table._displayattrs[col]
             result = []
             for i in xrange(self.GetNumberRows()):
                 result.append(self.table._displayattrs[col].value(self.table.items[i]))
             self.quit(result)
         elif keycode in (wx.WXK_ESCAPE, ord("Q")) and not (ctrl or sh):
             self.quit()
         elif keycode == ord("<"):
             row = self.GetGridCursorRow()
             col = self.GetGridCursorCol()
             if not event.ShiftDown():
                 newcol = col - 1
                 if newcol >= 0:
                     self.SetGridCursor(row, col - 1)
             else:
                 newcol = col + 1
                 if newcol < self.GetNumberCols():
                     self.SetGridCursor(row, col + 1)
         elif keycode == ord("D"):
             col = self.GetGridCursorCol()
             row = self.GetGridCursorRow()
             if not sh:
                 self.detail(row, col)
             else:
                 self.detail_attr(row, col)
         elif keycode == ord("F") and ctrl:
             if sh:
                 frame.enter_searchexpression(event)
             else:
                 frame.enter_searchtext(event)
         elif keycode == wx.WXK_F3:
             if sh:
                 frame.find_previous(event)
             else:
                 frame.find_next(event)
         elif keycode == ord("V"):
             if sh:
                 self.sortattrdesc()
             else:
                 self.sortattrasc()
         elif keycode == wx.WXK_DOWN:
             row = self.GetGridCursorRow()
             try:
                 item = self.table.items[row+1]
             except IndexError:
                 item = self.table.items[row]
             self.set_footer(item)
             event.Skip()
         elif keycode == wx.WXK_UP:
             row = self.GetGridCursorRow()
             if row >= 1:
                 item = self.table.items[row-1]
             else:
                 item = self.table.items[row]
             self.set_footer(item)
             event.Skip()
         elif keycode == wx.WXK_RIGHT:
             row = self.GetGridCursorRow()
             item = self.table.items[row]
             self.set_footer(item)
             event.Skip()
         elif keycode == wx.WXK_LEFT:
             row = self.GetGridCursorRow()
             item = self.table.items[row]
             self.set_footer(item)
             event.Skip()
         elif keycode == ord("R") or keycode == wx.WXK_F5:
             self.table.refresh_content(event)
         elif keycode == ord("I"):
             row = self.GetGridCursorRow()
             if not sh:
                 self.pickinput(row)
             else:
                 col = self.GetGridCursorCol()
                 self.pickinputattr(row, col)
         else:
             event.Skip()
 
     def delete_current_notebook(self):
         """
         deletes the current notebook tab
         """
         panel = self.GetParent()
         nb = panel.GetParent()
         current = nb.GetSelection()
         count = nb.GetPageCount()
         if count > 1:
             for i in xrange(count-1, current-1, -1):
                 nb.DeletePage(i)
             nb.GetCurrentPage().grid.SetFocus()
         else:
             frame = nb.GetParent()
             frame.SetStatusText("This is the last level!")
 
     def _doenter(self, value, *attrs):
         """
         "enter" a special item resulting in a new notebook tab
         """
         panel = self.GetParent()
         nb = panel.GetParent()
         frame = nb.GetParent()
         current = nb.GetSelection()
         count = nb.GetPageCount()
         try: # if we want to enter something non-iterable, e.g. a function
             if current + 1 == count and value is not self.input: # we have an event in the last tab
                 frame._add_notebook(value, *attrs)
             elif value != self.input: # we have to delete all tabs newer than [panel] first
                 for i in xrange(count-1, current, -1): # some tabs don't close if we don't close in *reverse* order
                     nb.DeletePage(i)
                 frame._add_notebook(value)
-        except TypeError, exc:
+        except TypeError as exc:
             if exc.__class__.__module__ == "exceptions":
                 msg = "%s: %s" % (exc.__class__.__name__, exc)
             else:
                 msg = "%s.%s: %s" % (exc.__class__.__module__, exc.__class__.__name__, exc)
             frame.SetStatusText(msg)
 
     def enterattr(self, row, col):
         try:
             attr = self.table._displayattrs[col]
             value = attr.value(self.table.items[row])
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             self._doenter(value)
 
     def set_footer(self, item):
         frame = self.GetParent().GetParent().GetParent()
         frame.SetStatusText(" ".join([str(text) for (style, text) in ipipe.xformat(item, "footer", 20)[2]]), 0)
 
     def enter(self, row):
         try:
             value = self.table.items[row]
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             self._doenter(value)
 
     def detail(self, row, col):
         """
         shows a detail-view of the current cell
         """
         try:
             attr = self.table._displayattrs[col]
             item = self.table.items[row]
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             attrs = [ipipe.AttributeDetail(item, attr) for attr in ipipe.xattrs(item, "detail")]
             self._doenter(attrs)
 
     def detail_attr(self, row, col):
         try:
             attr = self.table._displayattrs[col]
             item = attr.value(self.table.items[row])
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             attrs = [ipipe.AttributeDetail(item, attr) for attr in ipipe.xattrs(item, "detail")]
             self._doenter(attrs)
 
     def quit(self, result=None):
         """
         quit
         """
         frame = self.GetParent().GetParent().GetParent()
         if frame.helpdialog:
             frame.helpdialog.Destroy()
         app = frame.parent
         if app is not None:
             app.result = result
         frame.Close()
         frame.Destroy()
 
     def cell_doubleclicked(self, event):
         self.enterattr(event.GetRow(), event.GetCol())
         event.Skip()
 
     def cell_leftclicked(self, event):
         row = event.GetRow()
         item = self.table.items[row]
         self.set_footer(item)
         event.Skip()
 
     def pick(self, row):
         """
         pick a single row and return to the IPython prompt
         """
         try:
             value = self.table.items[row]
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             self.quit(value)
 
     def pickinput(self, row):
         try:
             value = self.table.items[row]
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             api = ipapi.get()
             api.set_next_input(str(value))
             self.quit(value)
 
     def pickinputattr(self, row, col):
         try:
             attr = self.table._displayattrs[col]
             value = attr.value(self.table.items[row])
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             api = ipapi.get()
             api.set_next_input(str(value))
             self.quit(value)
 
     def pickrows(self, rows):
         """
         pick multiple rows and return to the IPython prompt
         """
         try:
             value = [self.table.items[row] for row in rows]
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             self.quit(value)
 
     def pickrowsattr(self, rows, col):
         """"
         pick one column from multiple rows
         """
         values = []
         try:
             attr = self.table._displayattrs[col]
             for row in rows:
                 try:
                     values.append(attr.value(self.table.items[row]))
                 except (SystemExit, KeyboardInterrupt):
                     raise
                 except Exception:
                     raise #pass
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             self.quit(values)
 
     def pickattr(self, row, col):
         try:
             attr = self.table._displayattrs[col]
             value = attr.value(self.table.items[row])
-        except Exception, exc:
+        except Exception as exc:
             self.error_output(str(exc))
         else:
             self.quit(value)
 
 
 class IGridPanel(wx.Panel):
     # Each IGridPanel contains an IGridGrid
     def __init__(self, parent, input, *attrs):
         wx.Panel.__init__(self, parent, -1)
         self.grid = IGridGrid(self, input, *attrs)
         self.grid.FitInside()
         sizer = wx.BoxSizer(wx.VERTICAL)
         sizer.Add(self.grid, proportion=1, flag=wx.EXPAND | wx.ALL, border=10)
         self.SetSizer(sizer)
         sizer.Fit(self)
         sizer.SetSizeHints(self)
 
 
 class IGridHTMLHelp(wx.Frame):
     def __init__(self, parent, title, size):
         wx.Frame.__init__(self, parent, -1, title, size=size)
         html = wx.html.HtmlWindow(self)
         if "gtk2" in wx.PlatformInfo:
             html.SetStandardFonts()
         html.SetPage(help)
 
 
 class IGridFrame(wx.Frame):
     maxtitlelen = 30
 
     def __init__(self, parent, input):
         title =  " ".join([str(text) for (style, text) in ipipe.xformat(input, "header", 20)[2]])
         wx.Frame.__init__(self, None, title=title, size=(640, 480))
         self.menubar = wx.MenuBar()
         self.menucounter = 100
         self.m_help = wx.Menu()
         self.m_search = wx.Menu()
         self.m_sort = wx.Menu()
         self.m_refresh = wx.Menu()
         self.notebook = wx.Notebook(self, -1, style=0)
         self.statusbar = self.CreateStatusBar(1, wx.ST_SIZEGRIP)
         self.statusbar.SetFieldsCount(2)
         self.SetStatusWidths([-1, 200])
         self.parent = parent
         self._add_notebook(input)
         self.Bind(wx.EVT_CLOSE, self.OnCloseWindow)
         self.makemenu(self.m_sort, "&Sort (asc)\tV", "Sort ascending", self.sortasc)
         self.makemenu(self.m_sort, "Sort (&desc)\tShift-V", "Sort descending", self.sortdesc)
         self.makemenu(self.m_help, "&Help\tF1", "Help", self.display_help)
 #        self.makemenu(self.m_help, "&Show help in browser", "Show help in browser", self.display_help_in_browser)
         self.makemenu(self.m_search, "&Find text\tCTRL-F", "Find text", self.enter_searchtext)
         self.makemenu(self.m_search, "Find by &expression\tCTRL-Shift-F", "Find by expression", self.enter_searchexpression)
         self.makemenu(self.m_search, "Find &next\tF3", "Find next", self.find_next)
         self.makemenu(self.m_search, "Find &previous\tShift-F3", "Find previous", self.find_previous)
         self.makemenu(self.m_refresh, "&Refresh once \tF5", "Refresh once", self.refresh_once)
         self.makemenu(self.m_refresh, "Refresh every &1s", "Refresh every second", self.refresh_every_second)
         self.makemenu(self.m_refresh, "Refresh every &X seconds", "Refresh every X seconds", self.refresh_interval)
         self.makemenu(self.m_refresh, "&Stop all refresh timers", "Stop refresh timers", self.stop_refresh)
         self.menubar.Append(self.m_search, "&Find")
         self.menubar.Append(self.m_sort, "&Sort")
         self.menubar.Append(self.m_refresh, "&Refresh")
         self.menubar.Append(self.m_help, "&Help")
         self.SetMenuBar(self.menubar)
         self.searchtext = ""
         self.searchexpression = ""
         self.helpdialog = None
         self.refresh_interval = 1000
         self.SetStatusText("Refreshing inactive", 1)
 
     def refresh_once(self, event):
         table = self.notebook.GetPage(self.notebook.GetSelection()).grid.table
         table.refresh_content(event)
 
     def refresh_interval(self, event):
         table = self.notebook.GetPage(self.notebook.GetSelection()).grid.table
         dlg = wx.TextEntryDialog(self, "Enter refresh interval (milliseconds):", "Refresh timer:", defaultValue=str(self.refresh_interval))
         if dlg.ShowModal() == wx.ID_OK:
             try:
                 milliseconds = int(dlg.GetValue())
-            except ValueError, exc:
+            except ValueError as exc:
                 self.SetStatusText(str(exc))
             else:
                 table.timer.Start(milliseconds=milliseconds, oneShot=False)
                 self.SetStatusText("Refresh timer set to %s ms" % milliseconds)
                 self.SetStatusText("Refresh interval: %s ms" % milliseconds, 1)
                 self.refresh_interval = milliseconds
         dlg.Destroy()
 
     def stop_refresh(self, event):
         for i in xrange(self.notebook.GetPageCount()):
             nb = self.notebook.GetPage(i)
             nb.grid.table.timer.Stop()
             self.SetStatusText("Refreshing inactive", 1)
 
     def refresh_every_second(self, event):
         table = self.notebook.GetPage(self.notebook.GetSelection()).grid.table
         table.timer.Start(milliseconds=1000, oneShot=False)
         self.SetStatusText("Refresh interval: 1000 ms", 1)
 
     def sortasc(self, event):
         grid = self.notebook.GetPage(self.notebook.GetSelection()).grid
         grid.sortattrasc()
 
     def sortdesc(self, event):
         grid = self.notebook.GetPage(self.notebook.GetSelection()).grid
         grid.sortattrdesc()
 
     def find_previous(self, event):
         """
         find previous occurrences
         """
         grid = self.notebook.GetPage(self.notebook.GetSelection()).grid
         if self.searchtext:
             row = grid.GetGridCursorRow()
             col = grid.GetGridCursorCol()
             self.SetStatusText('Search mode: text; looking for %s' % self.searchtext)
             if col-1 >= 0:
                 grid.search(self.searchtext, row, col-1, False)
             else:
                 grid.search(self.searchtext, row-1, grid.table.GetNumberCols()-1, False)
         elif self.searchexpression:
             self.SetStatusText("Search mode: expression; looking for %s" % repr(self.searchexpression)[2:-1])
             grid.searchexpression(searchexp=self.searchexpression, search_forward=False)
         else:
             self.SetStatusText("No search yet: please enter search-text or -expression")
 
     def find_next(self, event):
         """
         find the next occurrence
         """
         grid = self.notebook.GetPage(self.notebook.GetSelection()).grid
         if self.searchtext != "":
             row = grid.GetGridCursorRow()
             col = grid.GetGridCursorCol()
             self.SetStatusText('Search mode: text; looking for %s' % self.searchtext)
             if col+1 < grid.table.GetNumberCols():
                 grid.search(self.searchtext, row, col+1)
             else:
                 grid.search(self.searchtext, row+1, 0)
         elif self.searchexpression != "":
             self.SetStatusText('Search mode: expression; looking for %s' % repr(self.searchexpression)[2:-1])
             grid.searchexpression(searchexp=self.searchexpression)
         else:
             self.SetStatusText("No search yet: please enter search-text or -expression")
 
     def display_help(self, event):
         """
         Display a help dialog
         """
         if self.helpdialog:
             self.helpdialog.Destroy()
         self.helpdialog = IGridHTMLHelp(None, title="Help", size=wx.Size(600,400))
         self.helpdialog.Show()
 
     def display_help_in_browser(self, event):
         """
         Show the help-HTML in a browser (as a ``HtmlWindow`` does not understand
         CSS this looks better)
         """
         filename = urllib.pathname2url(os.path.abspath(os.path.join(os.path.dirname(__file__), "igrid_help.html")))
         if not filename.startswith("file"):
             filename = "file:" + filename
         webbrowser.open(filename, new=1, autoraise=True)
 
     def enter_searchexpression(self, event):
         dlg = wx.TextEntryDialog(self, "Find:", "Find matching expression:", defaultValue=self.searchexpression)
         if dlg.ShowModal() == wx.ID_OK:
             self.searchexpression = dlg.GetValue()
             self.searchtext = ""
             self.SetStatusText('Search mode: expression; looking for %s' % repr(self.searchexpression)[2:-1])
             self.notebook.GetPage(self.notebook.GetSelection()).grid.searchexpression(self.searchexpression)
         dlg.Destroy()
 
     def makemenu(self, menu, label, help, cmd):
         menu.Append(self.menucounter, label, help)
         self.Bind(wx.EVT_MENU, cmd, id=self.menucounter)
         self.menucounter += 1
 
     def _add_notebook(self, input, *attrs):
         # Adds another notebook which has the starting object ``input``
         panel = IGridPanel(self.notebook, input, *attrs)
         text = str(ipipe.xformat(input, "header", self.maxtitlelen)[2])
         if len(text) >= self.maxtitlelen:
             text = text[:self.maxtitlelen].rstrip(".") + "..."
         self.notebook.AddPage(panel, text, True)
         panel.grid.SetFocus()
         self.Layout()
 
     def OnCloseWindow(self, event):
         self.Destroy()
 
     def enter_searchtext(self, event):
         # Displays a dialog asking for the searchtext
         dlg = wx.TextEntryDialog(self, "Find:", "Find in list", defaultValue=self.searchtext)
         if dlg.ShowModal() == wx.ID_OK:
             self.searchtext = dlg.GetValue()
             self.searchexpression = ""
             self.SetStatusText('Search mode: text; looking for %s' % self.searchtext)
             self.notebook.GetPage(self.notebook.GetSelection()).grid.search(self.searchtext)
         dlg.Destroy()
 
 
 class App(wx.App):
     def __init__(self, input):
         self.input = input
         self.result = None # Result to be returned to IPython. Set by quit().
         wx.App.__init__(self)
 
     def OnInit(self):
         frame = IGridFrame(self, self.input)
         frame.Show()
         self.SetTopWindow(frame)
         frame.Raise()
         return True
 
 
 class igrid(ipipe.Display):
     """
     This is a wx-based display object that can be used instead of ``ibrowse``
     (which is curses-based) or ``idump`` (which simply does a print).
     """
 
     if wx.VERSION < (2, 7):
         def display(self):
             try:
                 # Try to create a "standalone" frame. If this works we're probably
                 # running with -wthread.
                 # Note that this sets the parent of the frame to None, but we can't
                 # pass a result object back to the shell anyway.
                 frame = IGridFrame(None, self.input)
                 frame.Show()
                 frame.Raise()
             except wx.PyNoAppError:
                 # There's no wx application yet => create one.
                 app = App(self.input)
                 app.MainLoop()
                 return app.result
     else:
         # With wx 2.7 it gets simpler.
         def display(self):
             app = App(self.input)
             app.MainLoop()
             return app.result
 

IPython/deathrow/ipipe.py

@@ -1,2328 +1,2328 b''
 # -*- coding: iso-8859-1 -*-
 
 """
 ``ipipe`` provides classes to be used in an interactive Python session. Doing a
 ``from ipipe import *`` is the preferred way to do this. The name of all
 objects imported this way starts with ``i`` to minimize collisions.
 
 ``ipipe`` supports "pipeline expressions", which is something resembling Unix
 pipes. An example is::
 
     >>> ienv | isort("key.lower()")
 
 This gives a listing of all environment variables sorted by name.
 
 
 There are three types of objects in a pipeline expression:
 
 * ``Table``s: These objects produce items. Examples are ``ils`` (listing the
   current directory, ``ienv`` (listing environment variables), ``ipwd`` (listing
   user accounts) and ``igrp`` (listing user groups). A ``Table`` must be the
   first object in a pipe expression.
 
 * ``Pipe``s: These objects sit in the middle of a pipe expression. They
   transform the input in some way (e.g. filtering or sorting it). Examples are:
   ``ifilter`` (which filters the input pipe), ``isort`` (which sorts the input
   pipe) and ``ieval`` (which evaluates a function or expression for each object
   in the input pipe).
 
 * ``Display``s: These objects can be put as the last object in a pipeline
   expression. There are responsible for displaying the result of the pipeline
   expression. If a pipeline expression doesn't end in a display object a default
   display objects will be used. One example is ``ibrowse`` which is a ``curses``
   based browser.
 
 
 Adding support for pipeline expressions to your own objects can be done through
 three extensions points (all of them optional):
 
 * An object that will be displayed as a row by a ``Display`` object should
   implement the method ``__xattrs__(self, mode)`` method or register an
   implementation of the generic function ``xattrs``. For more info see ``xattrs``.
 
 * When an object ``foo`` is displayed by a ``Display`` object, the generic
   function ``xrepr`` is used.
 
 * Objects that can be iterated by ``Pipe``s must iterable. For special cases,
   where iteration for display is different than the normal iteration a special
   implementation can be registered with the generic function ``xiter``. This
   makes it possible to use dictionaries and modules in pipeline expressions,
   for example::
 
       >>> import sys
       >>> sys | ifilter("isinstance(value, int)") | idump
       key        |value
       api_version|      1012
       dllhandle  | 503316480
       hexversion |  33817328
       maxint     |2147483647
       maxunicode |     65535
       >>> sys.modules | ifilter("_.value is not None") | isort("_.key.lower()")
       ...
 
   Note: The expression strings passed to ``ifilter()`` and ``isort()`` can
   refer to the object to be filtered or sorted via the variable ``_`` and to any
   of the attributes of the object, i.e.::
 
       >>> sys.modules | ifilter("_.value is not None") | isort("_.key.lower()")
 
   does the same as::
 
       >>> sys.modules | ifilter("value is not None") | isort("key.lower()")
 
   In addition to expression strings, it's possible to pass callables (taking
   the object as an argument) to ``ifilter()``, ``isort()`` and ``ieval()``::
 
       >>> sys | ifilter(lambda _:isinstance(_.value, int)) \
       ...     | ieval(lambda _: (_.key, hex(_.value))) | idump
       0          |1
       api_version|0x3f4
       dllhandle  |0x1e000000
       hexversion |0x20402f0
       maxint     |0x7fffffff
       maxunicode |0xffff
 """
 
 skip_doctest = True  # ignore top-level docstring as a doctest.
 
 import sys, os, os.path, stat, glob, new, csv, datetime, types
 import itertools, mimetypes, StringIO
 
 try: # Python 2.3 compatibility
     import collections
 except ImportError:
     deque = list
 else:
     deque = collections.deque
 
 try: # Python 2.3 compatibility
     set
 except NameError:
     import sets
     set = sets.Set
 
 try: # Python 2.3 compatibility
     sorted
 except NameError:
     def sorted(iterator, key=None, reverse=False):
         items = list(iterator)
         if key is not None:
             items.sort(lambda i1, i2: cmp(key(i1), key(i2)))
         else:
             items.sort()
         if reverse:
             items.reverse()
         return items
 
 try: # Python 2.4 compatibility
     GeneratorExit
 except NameError:
     GeneratorExit = SystemExit
 
 try:
     import pwd
 except ImportError:
     pwd = None
 
 try:
     import grp
 except ImportError:
     grp = None
 
 from IPython.external import simplegeneric
 from IPython.external import path
 
 try:
     import IPython.utils.io
     from IPython.utils import generics
 except ImportError:
     Term = None
     generics = None
 
 from IPython.core import ipapi
 
 
 __all__ = [
     "ifile", "ils", "iglob", "iwalk", "ipwdentry", "ipwd", "igrpentry", "igrp",
     "icsv", "ix", "ichain", "isort", "ifilter", "ieval", "ienum",
     "ienv", "ihist", "ialias", "icap", "idump", "iless"
 ]
 
 
 os.stat_float_times(True) # enable microseconds
 
 
 class AttrNamespace(object):
     """
     Helper class that is used for providing a namespace for evaluating
     expressions containing attribute names of an object.
     """
     def __init__(self, wrapped):
         self.wrapped = wrapped
 
     def __getitem__(self, name):
         if name == "_":
             return self.wrapped
         try:
             return getattr(self.wrapped, name)
         except AttributeError:
             raise KeyError(name)
 
 # Python 2.3 compatibility
 # use eval workaround to find out which names are used in the
 # eval string and put them into the locals. This works for most
 # normal uses case, bizarre ones like accessing the locals()
 # will fail
 try:
     eval("_", None, AttrNamespace(None))
 except TypeError:
     real_eval = eval
     def eval(codestring, _globals, _locals):
         """
         eval(source[, globals[, locals]]) -> value
 
         Evaluate the source in the context of globals and locals.
         The source may be a string representing a Python expression
         or a code object as returned by compile().
         The globals must be a dictionary and locals can be any mappping.
 
         This function is a workaround for the shortcomings of
         Python 2.3's eval.
         """
 
         if isinstance(codestring, basestring):
             code = compile(codestring, "_eval", "eval")
         else:
             code = codestring
         newlocals = {}
         for name in code.co_names:
             try:
                 newlocals[name] = _locals[name]
             except KeyError:
                 pass
         return real_eval(code, _globals, newlocals)
 
 
 noitem = object()
 
 
 def item(iterator, index, default=noitem):
     """
     Return the ``index``th item from the iterator ``iterator``.
     ``index`` must be an integer (negative integers are relative to the
     end (i.e. the last items produced by the iterator)).
 
     If ``default`` is given, this will be the default value when
     the iterator doesn't contain an item at this position. Otherwise an
     ``IndexError`` will be raised.
 
     Note that using this function will partially or totally exhaust the
     iterator.
     """
     i = index
     if i>=0:
         for item in iterator:
             if not i:
                 return item
             i -= 1
     else:
         i = -index
         cache = deque()
         for item in iterator:
             cache.append(item)
             if len(cache)>i:
                 cache.popleft()
         if len(cache)==i:
             return cache.popleft()
     if default is noitem:
         raise IndexError(index)
     else:
         return default
 
 
 def getglobals(g):
     """
     Return the global namespace that is used for expression strings in
     ``ifilter`` and others. This is ``g`` or (if ``g`` is ``None``) IPython's
     user namespace.
     """
     if g is None:
         if ipapi is not None:
             api = ipapi.get()
             if api is not None:
                 return api.user_ns
         return globals()
     return g
 
 
 class Descriptor(object):
     """
     A ``Descriptor`` object is used for describing the attributes of objects.
     """
     def __hash__(self):
         return hash(self.__class__) ^ hash(self.key())
 
     def __eq__(self, other):
         return self.__class__ is other.__class__ and self.key() == other.key()
 
     def __ne__(self, other):
         return self.__class__ is not other.__class__ or self.key() != other.key()
 
     def key(self):
         pass
 
     def name(self):
         """
         Return the name of this attribute for display by a ``Display`` object
         (e.g. as a column title).
         """
         key = self.key()
         if key is None:
             return "_"
         return str(key)
 
     def attrtype(self, obj):
         """
         Return the type of this attribute (i.e. something like "attribute" or
         "method").
         """
 
     def valuetype(self, obj):
         """
         Return the type of this attribute value of the object ``obj``.
         """
 
     def value(self, obj):
         """
         Return the value of this attribute of the object ``obj``.
         """
 
     def doc(self, obj):
         """
         Return the documentation for this attribute.
         """
 
     def shortdoc(self, obj):
         """
         Return a short documentation for this attribute (defaulting to the
         first line).
         """
         doc = self.doc(obj)
         if doc is not None:
             doc = doc.strip().splitlines()[0].strip()
         return doc
 
     def iter(self, obj):
         """
         Return an iterator for this attribute of the object ``obj``.
         """
         return xiter(self.value(obj))
 
 
 class SelfDescriptor(Descriptor):
     """
     A ``SelfDescriptor`` describes the object itself.
     """
     def key(self):
         return None
 
     def attrtype(self, obj):
         return "self"
 
     def valuetype(self, obj):
         return type(obj)
 
     def value(self, obj):
         return obj
 
     def __repr__(self):
         return "Self"
 
 selfdescriptor = SelfDescriptor() # there's no need for more than one
 
 
 class AttributeDescriptor(Descriptor):
     """
     An ``AttributeDescriptor`` describes a simple attribute of an object.
     """
     __slots__ = ("_name", "_doc")
 
     def __init__(self, name, doc=None):
         self._name = name
         self._doc = doc
 
     def key(self):
         return self._name
 
     def doc(self, obj):
         return self._doc
 
     def attrtype(self, obj):
         return "attr"
 
     def valuetype(self, obj):
         return type(getattr(obj, self._name))
 
     def value(self, obj):
         return getattr(obj, self._name)
 
     def __repr__(self):
         if self._doc is None:
             return "Attribute(%r)" % self._name
         else:
             return "Attribute(%r, %r)" % (self._name, self._doc)
 
 
 class IndexDescriptor(Descriptor):
     """
     An ``IndexDescriptor`` describes an "attribute" of an object that is fetched
     via ``__getitem__``.
     """
     __slots__ = ("_index",)
 
     def __init__(self, index):
         self._index = index
 
     def key(self):
         return self._index
 
     def attrtype(self, obj):
         return "item"
 
     def valuetype(self, obj):
         return type(obj[self._index])
 
     def value(self, obj):
         return obj[self._index]
 
     def __repr__(self):
         return "Index(%r)" % self._index
 
 
 class MethodDescriptor(Descriptor):
     """
     A ``MethodDescriptor`` describes a method of an object that can be called
     without argument. Note that this method shouldn't change the object.
     """
     __slots__ = ("_name", "_doc")
 
     def __init__(self, name, doc=None):
         self._name = name
         self._doc = doc
 
     def key(self):
         return self._name
 
     def doc(self, obj):
         if self._doc is None:
             return getattr(obj, self._name).__doc__
         return self._doc
 
     def attrtype(self, obj):
         return "method"
 
     def valuetype(self, obj):
         return type(self.value(obj))
 
     def value(self, obj):
         return getattr(obj, self._name)()
 
     def __repr__(self):
         if self._doc is None:
             return "Method(%r)" % self._name
         else:
             return "Method(%r, %r)" % (self._name, self._doc)
 
 
 class IterAttributeDescriptor(Descriptor):
     """
     An ``IterAttributeDescriptor`` works like an ``AttributeDescriptor`` but
     doesn't return an attribute values (because this value might be e.g. a large
     list).
     """
     __slots__ = ("_name", "_doc")
 
     def __init__(self, name, doc=None):
         self._name = name
         self._doc = doc
 
     def key(self):
         return self._name
 
     def doc(self, obj):
         return self._doc
 
     def attrtype(self, obj):
         return "iter"
 
     def valuetype(self, obj):
         return noitem
 
     def value(self, obj):
         return noitem
 
     def iter(self, obj):
         return xiter(getattr(obj, self._name))
 
     def __repr__(self):
         if self._doc is None:
             return "IterAttribute(%r)" % self._name
         else:
             return "IterAttribute(%r, %r)" % (self._name, self._doc)
 
 
 class IterMethodDescriptor(Descriptor):
     """
     An ``IterMethodDescriptor`` works like an ``MethodDescriptor`` but doesn't
     return an attribute values (because this value might be e.g. a large list).
     """
     __slots__ = ("_name", "_doc")
 
     def __init__(self, name, doc=None):
         self._name = name
         self._doc = doc
 
     def key(self):
         return self._name
 
     def doc(self, obj):
         if self._doc is None:
             return getattr(obj, self._name).__doc__
         return self._doc
 
     def attrtype(self, obj):
         return "itermethod"
 
     def valuetype(self, obj):
         return noitem
 
     def value(self, obj):
         return noitem
 
     def iter(self, obj):
         return xiter(getattr(obj, self._name)())
 
     def __repr__(self):
         if self._doc is None:
             return "IterMethod(%r)" % self._name
         else:
             return "IterMethod(%r, %r)" % (self._name, self._doc)
 
 
 class FunctionDescriptor(Descriptor):
     """
     A ``FunctionDescriptor`` turns a function into a descriptor. The function
     will be called with the object to get the type and value of the attribute.
     """
     __slots__ = ("_function", "_name", "_doc")
 
     def __init__(self, function, name=None, doc=None):
         self._function = function
         self._name = name
         self._doc = doc
 
     def key(self):
         return self._function
 
     def name(self):
         if self._name is not None:
             return self._name
         return getattr(self._function, "__xname__", self._function.__name__)
 
     def doc(self, obj):
         if self._doc is None:
             return self._function.__doc__
         return self._doc
 
     def attrtype(self, obj):
         return "function"
 
     def valuetype(self, obj):
         return type(self._function(obj))
 
     def value(self, obj):
         return self._function(obj)
 
     def __repr__(self):
         if self._doc is None:
             return "Function(%r)" % self._name
         else:
             return "Function(%r, %r)" % (self._name, self._doc)
 
 
 class Table(object):
     """
     A ``Table`` is an object that produces items (just like a normal Python
     iterator/generator does) and can be used as the first object in a pipeline
     expression. The displayhook will open the default browser for such an object
     (instead of simply printing the ``repr()`` result).
     """
 
     # We want to support ``foo`` and ``foo()`` in pipeline expression:
     # So we implement the required operators (``|`` and ``+``) in the metaclass,
     # instantiate the class and forward the operator to the instance
     class __metaclass__(type):
         def __iter__(self):
             return iter(self())
 
         def __or__(self, other):
             return self() | other
 
         def __add__(self, other):
             return self() + other
 
         def __radd__(self, other):
             return other + self()
 
         def __getitem__(self, index):
             return self()[index]
 
     def __getitem__(self, index):
         return item(self, index)
 
     def __contains__(self, item):
         for haveitem in self:
             if item == haveitem:
                 return True
         return False
 
     def __or__(self, other):
         # autoinstantiate right hand side
         if isinstance(other, type) and issubclass(other, (Table, Display)):
             other = other()
         # treat simple strings and functions as ``ieval`` instances
         elif not isinstance(other, Display) and not isinstance(other, Table):
             other = ieval(other)
         # forward operations to the right hand side
         return other.__ror__(self)
 
     def __add__(self, other):
         # autoinstantiate right hand side
         if isinstance(other, type) and issubclass(other, Table):
             other = other()
         return ichain(self, other)
 
     def __radd__(self, other):
         # autoinstantiate left hand side
         if isinstance(other, type) and issubclass(other, Table):
             other = other()
         return ichain(other, self)
 
 
 class Pipe(Table):
     """
     A ``Pipe`` is an object that can be used in a pipeline expression. It
     processes the objects it gets from its input ``Table``/``Pipe``. Note that
     a ``Pipe`` object can't be used as the first object in a pipeline
     expression, as it doesn't produces items itself.
     """
     class __metaclass__(Table.__metaclass__):
         def __ror__(self, input):
             return input | self()
 
     def __ror__(self, input):
         # autoinstantiate left hand side
         if isinstance(input, type) and issubclass(input, Table):
             input = input()
         self.input = input
         return self
 
 
 def xrepr(item, mode="default"):
     """
     Generic function that adds color output and different display modes to ``repr``.
 
     The result of an ``xrepr`` call is iterable and consists of ``(style, string)``
     tuples. The ``style`` in this tuple must be a ``Style`` object from the
     ``astring`` module. To reconfigure the output the first yielded tuple can be
     a ``(aligment, full)`` tuple instead of a ``(style, string)`` tuple.
     ``alignment``  can be -1 for left aligned, 0 for centered and 1 for right
     aligned (the default is left alignment). ``full`` is a boolean that specifies
     whether the complete output must be displayed or the ``Display`` object is
     allowed to stop output after enough text has been produced (e.g. a syntax
     highlighted text line would use ``True``, but for a large data structure
     (i.e. a nested list, tuple or dictionary) ``False`` would be used).
     The default is full output.
 
     There are four different possible values for ``mode`` depending on where
     the ``Display`` object will display ``item``:
 
     ``"header"``
         ``item`` will be displayed in a header line (this is used by ``ibrowse``).
 
     ``"footer"``
         ``item`` will be displayed in a footer line (this is used by ``ibrowse``).
 
     ``"cell"``
         ``item`` will be displayed in a table cell/list.
 
     ``"default"``
         default mode. If an ``xrepr`` implementation recursively outputs objects,
         ``"default"`` must be passed in the recursive calls to ``xrepr``.
 
     If no implementation is registered for ``item``, ``xrepr`` will try the
     ``__xrepr__`` method on ``item``. If ``item`` doesn't have an ``__xrepr__``
     method it falls back to ``repr``/``__repr__`` for all modes.
     """
     try:
         func = item.__xrepr__
     except AttributeError:
         yield (astyle.style_default, repr(item))
     else:
         try:
             for x in func(mode):
                 yield x
         except (KeyboardInterrupt, SystemExit, GeneratorExit):
             raise
         except Exception:
             yield (astyle.style_default, repr(item))
 xrepr = simplegeneric.generic(xrepr)
 
 
 def xrepr_none(self, mode="default"):
     yield (astyle.style_type_none, repr(self))
 xrepr.when_object(None)(xrepr_none)
 
 
 def xrepr_noitem(self, mode="default"):
     yield (2, True)
     yield (astyle.style_nodata, "<?>")
 xrepr.when_object(noitem)(xrepr_noitem)
 
 
 def xrepr_bool(self, mode="default"):
     yield (astyle.style_type_bool, repr(self))
 xrepr.when_type(bool)(xrepr_bool)
 
 
 def xrepr_str(self, mode="default"):
     if mode == "cell":
         yield (astyle.style_default, repr(self.expandtabs(tab))[1:-1])
     else:
         yield (astyle.style_default, repr(self))
 xrepr.when_type(str)(xrepr_str)
 
 
 def xrepr_unicode(self, mode="default"):
     if mode == "cell":
         yield (astyle.style_default, repr(self.expandtabs(tab))[2:-1])
     else:
         yield (astyle.style_default, repr(self))
 xrepr.when_type(unicode)(xrepr_unicode)
 
 
 def xrepr_number(self, mode="default"):
     yield (1, True)
     yield (astyle.style_type_number, repr(self))
 xrepr.when_type(int)(xrepr_number)
 xrepr.when_type(long)(xrepr_number)
 xrepr.when_type(float)(xrepr_number)
 
 
 def xrepr_complex(self, mode="default"):
     yield (astyle.style_type_number, repr(self))
 xrepr.when_type(complex)(xrepr_number)
 
 
 def xrepr_datetime(self, mode="default"):
     if mode == "cell":
         # Don't use strftime() here, as this requires year >= 1900
         yield (astyle.style_type_datetime,
                "%04d-%02d-%02d %02d:%02d:%02d.%06d" % \
                     (self.year, self.month, self.day,
                      self.hour, self.minute, self.second,
                      self.microsecond),
                 )
     else:
         yield (astyle.style_type_datetime, repr(self))
 xrepr.when_type(datetime.datetime)(xrepr_datetime)
 
 
 def xrepr_date(self, mode="default"):
     if mode == "cell":
         yield (astyle.style_type_datetime,
                "%04d-%02d-%02d" % (self.year, self.month, self.day))
     else:
         yield (astyle.style_type_datetime, repr(self))
 xrepr.when_type(datetime.date)(xrepr_date)
 
 
 def xrepr_time(self, mode="default"):
     if mode == "cell":
         yield (astyle.style_type_datetime,
                 "%02d:%02d:%02d.%06d" % \
                     (self.hour, self.minute, self.second, self.microsecond))
     else:
         yield (astyle.style_type_datetime, repr(self))
 xrepr.when_type(datetime.time)(xrepr_time)
 
 
 def xrepr_timedelta(self, mode="default"):
     yield (astyle.style_type_datetime, repr(self))
 xrepr.when_type(datetime.timedelta)(xrepr_timedelta)
 
 
 def xrepr_type(self, mode="default"):
     if self.__module__ == "__builtin__":
         yield (astyle.style_type_type, self.__name__)
     else:
         yield (astyle.style_type_type, "%s.%s" % (self.__module__, self.__name__))
 xrepr.when_type(type)(xrepr_type)
 
 
 def xrepr_exception(self, mode="default"):
     if self.__class__.__module__ == "exceptions":
         classname = self.__class__.__name__
     else:
         classname = "%s.%s" % \
             (self.__class__.__module__, self.__class__.__name__)
     if mode == "header" or mode == "footer":
         yield (astyle.style_error, "%s: %s" % (classname, self))
     else:
         yield (astyle.style_error, classname)
 xrepr.when_type(Exception)(xrepr_exception)
 
 
 def xrepr_listtuple(self, mode="default"):
     if mode == "header" or mode == "footer":
         if self.__class__.__module__ == "__builtin__":
             classname = self.__class__.__name__
         else:
             classname = "%s.%s" % \
                 (self.__class__.__module__,self.__class__.__name__)
         yield (astyle.style_default,
                "<%s object with %d items at 0x%x>" % \
                    (classname, len(self), id(self)))
     else:
         yield (-1, False)
         if isinstance(self, list):
             yield (astyle.style_default, "[")
             end = "]"
         else:
             yield (astyle.style_default, "(")
             end = ")"
         for (i, subself) in enumerate(self):
             if i:
                 yield (astyle.style_default, ", ")
             for part in xrepr(subself, "default"):
                 yield part
         yield (astyle.style_default, end)
 xrepr.when_type(list)(xrepr_listtuple)
 xrepr.when_type(tuple)(xrepr_listtuple)
 
 
 def xrepr_dict(self, mode="default"):
     if mode == "header" or mode == "footer":
         if self.__class__.__module__ == "__builtin__":
             classname = self.__class__.__name__
         else:
             classname = "%s.%s" % \
                 (self.__class__.__module__,self.__class__.__name__)
         yield (astyle.style_default,
                "<%s object with %d items at 0x%x>" % \
                 (classname, len(self), id(self)))
     else:
         yield (-1, False)
         if isinstance(self, dict):
             yield (astyle.style_default, "{")
             end = "}"
         else:
             yield (astyle.style_default, "dictproxy((")
             end = "})"
         for (i, (key, value)) in enumerate(self.iteritems()):
             if i:
                 yield (astyle.style_default, ", ")
             for part in xrepr(key, "default"):
                 yield part
             yield (astyle.style_default, ": ")
             for part in xrepr(value, "default"):
                 yield part
         yield (astyle.style_default, end)
 xrepr.when_type(dict)(xrepr_dict)
 xrepr.when_type(types.DictProxyType)(xrepr_dict)
 
 
 def upgradexattr(attr):
     """
     Convert an attribute descriptor string to a real descriptor object.
 
     If attr already is a descriptor object return it unmodified. A
     ``SelfDescriptor`` will be returned if ``attr`` is ``None``. ``"foo"``
     returns an ``AttributeDescriptor`` for the attribute named ``"foo"``.
     ``"foo()"`` returns a ``MethodDescriptor`` for the method named ``"foo"``.
     ``"-foo"`` will return an ``IterAttributeDescriptor`` for the attribute
     named ``"foo"`` and ``"-foo()"`` will return an ``IterMethodDescriptor``
     for the method named ``"foo"``. Furthermore integers will return the appropriate
     ``IndexDescriptor`` and callables will return a ``FunctionDescriptor``.
     """
     if attr is None:
         return selfdescriptor
     elif isinstance(attr, Descriptor):
         return attr
     elif isinstance(attr, basestring):
         if attr.endswith("()"):
             if attr.startswith("-"):
                 return IterMethodDescriptor(attr[1:-2])
             else:
                 return MethodDescriptor(attr[:-2])
         else:
             if attr.startswith("-"):
                 return IterAttributeDescriptor(attr[1:])
             else:
                 return AttributeDescriptor(attr)
     elif isinstance(attr, (int, long)):
         return IndexDescriptor(attr)
     elif callable(attr):
         return FunctionDescriptor(attr)
     else:
         raise TypeError("can't handle descriptor %r" % attr)
 
 
 def xattrs(item, mode="default"):
     """
     Generic function that returns an iterable of attribute descriptors
     to be used for displaying the attributes ob the object ``item`` in display
     mode ``mode``.
 
     There are two possible modes:
 
     ``"detail"``
         The ``Display`` object wants to display a detailed list of the object
         attributes.
 
     ``"default"``
         The ``Display`` object wants to display the object in a list view.
 
     If no implementation is registered for the object ``item`` ``xattrs`` falls
     back to trying the ``__xattrs__`` method of the object. If this doesn't
     exist either, ``dir(item)`` is used for ``"detail"`` mode and ``(None,)``
     for ``"default"`` mode.
 
     The implementation must yield attribute descriptors (see the class
     ``Descriptor`` for more info). The ``__xattrs__`` method may also return
     attribute descriptor strings (and ``None``) which will be converted to real
     descriptors by ``upgradexattr()``.
     """
     try:
         func = item.__xattrs__
     except AttributeError:
         if mode == "detail":
             for attrname in dir(item):
                 yield AttributeDescriptor(attrname)
         else:
             yield selfdescriptor
     else:
         for attr in func(mode):
             yield upgradexattr(attr)
 xattrs = simplegeneric.generic(xattrs)
 
 
 def xattrs_complex(self, mode="default"):
     if mode == "detail":
         return (AttributeDescriptor("real"), AttributeDescriptor("imag"))
     return (selfdescriptor,)
 xattrs.when_type(complex)(xattrs_complex)
 
 
 def _isdict(item):
     try:
         itermeth = item.__class__.__iter__
     except (AttributeError, TypeError):
         return False
     return itermeth is dict.__iter__ or itermeth is types.DictProxyType.__iter__
 
 
 def _isstr(item):
     if not isinstance(item, basestring):
         return False
     try:
         itermeth = item.__class__.__iter__
     except AttributeError:
         return True
     return False # ``__iter__`` has been redefined
 
 
 def xiter(item):
     """
     Generic function that implements iteration for pipeline expression. If no
     implementation is registered for ``item`` ``xiter`` falls back to ``iter``.
     """
     try:
         func = item.__xiter__
     except AttributeError:
         if _isdict(item):
             def items(item):
                 fields = ("key", "value")
                 for (key, value) in item.iteritems():
                     yield Fields(fields, key=key, value=value)
             return items(item)
         elif isinstance(item, new.module):
             def items(item):
                 fields = ("key", "value")
                 for key in sorted(item.__dict__):
                     yield Fields(fields, key=key, value=getattr(item, key))
             return items(item)
         elif _isstr(item):
             if not item:
                 raise ValueError("can't enter empty string")
             lines = item.splitlines()
             if len(lines) == 1:
                def iterone(item):
                    yield item
                return iterone(item)
             else:
                 return iter(lines)
         return iter(item)
     else:
         return iter(func()) # iter() just to be safe
 xiter = simplegeneric.generic(xiter)
 
 
 class ichain(Pipe):
     """
     Chains multiple ``Table``s into one.
     """
 
     def __init__(self, *iters):
         self.iters = iters
 
     def __iter__(self):
         return itertools.chain(*self.iters)
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer":
             for (i, item) in enumerate(self.iters):
                 if i:
                     yield (astyle.style_default, "+")
                 if isinstance(item, Pipe):
                     yield (astyle.style_default, "(")
                 for part in xrepr(item, mode):
                     yield part
                 if isinstance(item, Pipe):
                     yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         args = ", ".join([repr(it) for it in self.iters])
         return "%s.%s(%s)" % \
             (self.__class__.__module__, self.__class__.__name__, args)
 
 
 class ifile(path.path):
     """
     file (or directory) object.
     """
 
     def getmode(self):
         return self.stat().st_mode
     mode = property(getmode, None, None, "Access mode")
 
     def gettype(self):
         data = [
             (stat.S_ISREG, "file"),
             (stat.S_ISDIR, "dir"),
             (stat.S_ISCHR, "chardev"),
             (stat.S_ISBLK, "blockdev"),
             (stat.S_ISFIFO, "fifo"),
             (stat.S_ISLNK, "symlink"),
             (stat.S_ISSOCK,"socket"),
         ]
         lstat = self.lstat()
         if lstat is not None:
             types = set([text for (func, text) in data if func(lstat.st_mode)])
         else:
             types = set()
         m = self.mode
         types.update([text for (func, text) in data if func(m)])
         return ", ".join(types)
     type = property(gettype, None, None, "file type (file, directory, link, etc.)")
 
     def getmodestr(self):
         m = self.mode
         data = [
             (stat.S_IRUSR, "-r"),
             (stat.S_IWUSR, "-w"),
             (stat.S_IXUSR, "-x"),
             (stat.S_IRGRP, "-r"),
             (stat.S_IWGRP, "-w"),
             (stat.S_IXGRP, "-x"),
             (stat.S_IROTH, "-r"),
             (stat.S_IWOTH, "-w"),
             (stat.S_IXOTH, "-x"),
         ]
         return "".join([text[bool(m&bit)] for (bit, text) in data])
 
     modestr = property(getmodestr, None, None, "Access mode as string")
 
     def getblocks(self):
         return self.stat().st_blocks
     blocks = property(getblocks, None, None, "File size in blocks")
 
     def getblksize(self):
         return self.stat().st_blksize
     blksize = property(getblksize, None, None, "Filesystem block size")
 
     def getdev(self):
         return self.stat().st_dev
     dev = property(getdev)
 
     def getnlink(self):
         return self.stat().st_nlink
     nlink = property(getnlink, None, None, "Number of links")
 
     def getuid(self):
         return self.stat().st_uid
     uid = property(getuid, None, None, "User id of file owner")
 
     def getgid(self):
         return self.stat().st_gid
     gid = property(getgid, None, None, "Group id of file owner")
 
     def getowner(self):
         stat = self.stat()
         try:
             return pwd.getpwuid(stat.st_uid).pw_name
         except KeyError:
             return stat.st_uid
     owner = property(getowner, None, None, "Owner name (or id)")
 
     def getgroup(self):
         stat = self.stat()
         try:
             return grp.getgrgid(stat.st_gid).gr_name
         except KeyError:
             return stat.st_gid
     group = property(getgroup, None, None, "Group name (or id)")
 
     def getadate(self):
         return datetime.datetime.utcfromtimestamp(self.atime)
     adate = property(getadate, None, None, "Access date")
 
     def getcdate(self):
         return datetime.datetime.utcfromtimestamp(self.ctime)
     cdate = property(getcdate, None, None, "Creation date")
 
     def getmdate(self):
         return datetime.datetime.utcfromtimestamp(self.mtime)
     mdate = property(getmdate, None, None, "Modification date")
 
     def mimetype(self):
         """
         Return MIME type guessed from the extension.
         """
         return mimetypes.guess_type(self.basename())[0]
 
     def encoding(self):
         """
         Return guessed compression (like "compress" or "gzip").
         """
         return mimetypes.guess_type(self.basename())[1]
 
     def __repr__(self):
         return "ifile(%s)" % path._base.__repr__(self)
 
     if sys.platform == "win32":
         defaultattrs = (None, "type", "size", "modestr", "mdate")
     else:
         defaultattrs = (None, "type", "size", "modestr", "owner", "group", "mdate")
 
     def __xattrs__(self, mode="default"):
         if mode == "detail":
             return (
                 "name",
                 "basename()",
                 "abspath()",
                 "realpath()",
                 "type",
                 "mode",
                 "modestr",
                 "stat()",
                 "lstat()",
                 "uid",
                 "gid",
                 "owner",
                 "group",
                 "dev",
                 "nlink",
                 "ctime",
                 "mtime",
                 "atime",
                 "cdate",
                 "mdate",
                 "adate",
                 "size",
                 "blocks",
                 "blksize",
                 "isdir()",
                 "islink()",
                 "mimetype()",
                 "encoding()",
                 "-listdir()",
                 "-dirs()",
                 "-files()",
                 "-walk()",
                 "-walkdirs()",
                 "-walkfiles()",
             )
         else:
             return self.defaultattrs
 
 
 def xiter_ifile(self):
     if self.isdir():
         yield (self / os.pardir).abspath()
         for child in sorted(self.listdir()):
             yield child
     else:
         f = self.open("rb")
         for line in f:
             yield line
         f.close()
 xiter.when_type(ifile)(xiter_ifile)
 
 
 # We need to implement ``xrepr`` for ``ifile`` as a generic function, because
 # otherwise ``xrepr_str`` would kick in.
 def xrepr_ifile(self, mode="default"):
     try:
         if self.isdir():
             name = "idir"
             style = astyle.style_dir
         else:
             name = "ifile"
             style = astyle.style_file
     except IOError:
         name = "ifile"
         style = astyle.style_default
     if mode in ("cell", "header", "footer"):
         abspath = repr(path._base(self.normpath()))
         if abspath.startswith("u"):
             abspath = abspath[2:-1]
         else:
             abspath = abspath[1:-1]
         if mode == "cell":
             yield (style, abspath)
         else:
             yield (style, "%s(%s)" % (name, abspath))
     else:
         yield (style, repr(self))
 xrepr.when_type(ifile)(xrepr_ifile)
 
 
 class ils(Table):
     """
     List the current (or a specified) directory.
 
     Examples::
 
         >>> ils
         <class 'IPython.extensions.ipipe.ils'>
         >>> ils("/usr/local/lib/python2.4")
         IPython.extensions.ipipe.ils('/usr/local/lib/python2.4')
         >>> ils("~")
         IPython.extensions.ipipe.ils('/home/fperez')
         # all-random
     """
     def __init__(self, base=os.curdir, dirs=True, files=True):
         self.base = os.path.expanduser(base)
         self.dirs = dirs
         self.files = files
 
     def __iter__(self):
         base = ifile(self.base)
         yield (base / os.pardir).abspath()
         for child in sorted(base.listdir()):
             if self.dirs:
                 if self.files:
                     yield child
                 else:
                     if child.isdir():
                         yield child
             elif self.files:
                 if not child.isdir():
                     yield child
 
     def __xrepr__(self, mode="default"):
        return xrepr(ifile(self.base), mode)
 
     def __repr__(self):
         return "%s.%s(%r)" % \
             (self.__class__.__module__, self.__class__.__name__, self.base)
 
 
 class iglob(Table):
     """
     List all files and directories matching a specified pattern.
     (See ``glob.glob()`` for more info.).
 
     Examples::
 
         >>> iglob("*.py")
         IPython.extensions.ipipe.iglob('*.py')
     """
     def __init__(self, glob):
         self.glob = glob
 
     def __iter__(self):
         for name in glob.glob(self.glob):
             yield ifile(name)
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer" or mode == "cell":
             yield (astyle.style_default,
                    "%s(%r)" % (self.__class__.__name__, self.glob))
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "%s.%s(%r)" % \
             (self.__class__.__module__, self.__class__.__name__, self.glob)
 
 
 class iwalk(Table):
     """
     List all files and directories in a directory and it's subdirectory::
 
         >>> iwalk
         <class 'IPython.extensions.ipipe.iwalk'>
         >>> iwalk("/usr/lib")
         IPython.extensions.ipipe.iwalk('/usr/lib')
         >>> iwalk("~")
         IPython.extensions.ipipe.iwalk('/home/fperez')  # random
         
     """
     def __init__(self, base=os.curdir, dirs=True, files=True):
         self.base = os.path.expanduser(base)
         self.dirs = dirs
         self.files = files
 
     def __iter__(self):
         for (dirpath, dirnames, filenames) in os.walk(self.base):
             if self.dirs:
                 for name in sorted(dirnames):
                     yield ifile(os.path.join(dirpath, name))
             if self.files:
                 for name in sorted(filenames):
                     yield ifile(os.path.join(dirpath, name))
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer" or mode == "cell":
             yield (astyle.style_default,
                    "%s(%r)" % (self.__class__.__name__, self.base))
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "%s.%s(%r)" % \
             (self.__class__.__module__, self.__class__.__name__, self.base)
 
 
 class ipwdentry(object):
     """
     ``ipwdentry`` objects encapsulate entries in the Unix user account and
     password database.
     """
     def __init__(self, id):
         self._id = id
         self._entry = None
 
     def __eq__(self, other):
         return self.__class__ is other.__class__ and self._id == other._id
 
     def __ne__(self, other):
         return self.__class__ is not other.__class__ or self._id != other._id
 
     def _getentry(self):
         if self._entry is None:
             if isinstance(self._id, basestring):
                 self._entry = pwd.getpwnam(self._id)
             else:
                 self._entry = pwd.getpwuid(self._id)
         return self._entry
 
     def getname(self):
         if isinstance(self._id, basestring):
             return self._id
         else:
             return self._getentry().pw_name
     name = property(getname, None, None, "User name")
 
     def getpasswd(self):
         return self._getentry().pw_passwd
     passwd = property(getpasswd, None, None, "Password")
 
     def getuid(self):
         if isinstance(self._id, basestring):
             return self._getentry().pw_uid
         else:
             return self._id
     uid = property(getuid, None, None, "User id")
 
     def getgid(self):
         return self._getentry().pw_gid
     gid = property(getgid, None, None, "Primary group id")
 
     def getgroup(self):
         return igrpentry(self.gid)
     group = property(getgroup, None, None, "Group")
 
     def getgecos(self):
         return self._getentry().pw_gecos
     gecos = property(getgecos, None, None, "Information (e.g. full user name)")
 
     def getdir(self):
         return self._getentry().pw_dir
     dir = property(getdir, None, None, "$HOME directory")
 
     def getshell(self):
         return self._getentry().pw_shell
     shell = property(getshell, None, None, "Login shell")
 
     def __xattrs__(self, mode="default"):
        return ("name", "passwd", "uid", "gid", "gecos", "dir", "shell")
 
     def __repr__(self):
         return "%s.%s(%r)" % \
             (self.__class__.__module__, self.__class__.__name__, self._id)
 
 
 class ipwd(Table):
     """
     List all entries in the Unix user account and password database.
 
     Example::
 
         >>> ipwd | isort("uid")
         <IPython.extensions.ipipe.isort key='uid' reverse=False at 0x849efec>
         # random
     """
     def __iter__(self):
         for entry in pwd.getpwall():
             yield ipwdentry(entry.pw_name)
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer" or mode == "cell":
             yield (astyle.style_default, "%s()" % self.__class__.__name__)
         else:
             yield (astyle.style_default, repr(self))
 
 
 class igrpentry(object):
     """
     ``igrpentry`` objects encapsulate entries in the Unix group database.
     """
     def __init__(self, id):
         self._id = id
         self._entry = None
 
     def __eq__(self, other):
         return self.__class__ is other.__class__ and self._id == other._id
 
     def __ne__(self, other):
         return self.__class__ is not other.__class__ or self._id != other._id
 
     def _getentry(self):
         if self._entry is None:
             if isinstance(self._id, basestring):
                 self._entry = grp.getgrnam(self._id)
             else:
                 self._entry = grp.getgrgid(self._id)
         return self._entry
 
     def getname(self):
         if isinstance(self._id, basestring):
             return self._id
         else:
             return self._getentry().gr_name
     name = property(getname, None, None, "Group name")
 
     def getpasswd(self):
         return self._getentry().gr_passwd
     passwd = property(getpasswd, None, None, "Password")
 
     def getgid(self):
         if isinstance(self._id, basestring):
             return self._getentry().gr_gid
         else:
             return self._id
     gid = property(getgid, None, None, "Group id")
 
     def getmem(self):
         return self._getentry().gr_mem
     mem = property(getmem, None, None, "Members")
 
     def __xattrs__(self, mode="default"):
         return ("name", "passwd", "gid", "mem")
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer" or mode == "cell":
             yield (astyle.style_default, "group ")
             try:
                 yield (astyle.style_default, self.name)
             except KeyError:
                 if isinstance(self._id, basestring):
                     yield (astyle.style_default, self.name_id)
                 else:
                     yield (astyle.style_type_number, str(self._id))
         else:
             yield (astyle.style_default, repr(self))
 
     def __iter__(self):
         for member in self.mem:
             yield ipwdentry(member)
 
     def __repr__(self):
         return "%s.%s(%r)" % \
             (self.__class__.__module__, self.__class__.__name__, self._id)
 
 
 class igrp(Table):
     """
     This ``Table`` lists all entries in the Unix group database.
     """
     def __iter__(self):
         for entry in grp.getgrall():
             yield igrpentry(entry.gr_name)
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer":
             yield (astyle.style_default, "%s()" % self.__class__.__name__)
         else:
             yield (astyle.style_default, repr(self))
 
 
 class Fields(object):
     def __init__(self, fieldnames, **fields):
         self.__fieldnames = [upgradexattr(fieldname) for fieldname in fieldnames]
         for (key, value) in fields.iteritems():
             setattr(self, key, value)
 
     def __xattrs__(self, mode="default"):
         return self.__fieldnames
 
     def __xrepr__(self, mode="default"):
         yield (-1, False)
         if mode == "header" or mode == "cell":
             yield (astyle.style_default, self.__class__.__name__)
             yield (astyle.style_default, "(")
             for (i, f) in enumerate(self.__fieldnames):
                 if i:
                     yield (astyle.style_default, ", ")
                 yield (astyle.style_default, f.name())
                 yield (astyle.style_default, "=")
                 for part in xrepr(getattr(self, f), "default"):
                     yield part
             yield (astyle.style_default, ")")
         elif mode == "footer":
             yield (astyle.style_default, self.__class__.__name__)
             yield (astyle.style_default, "(")
             for (i, f) in enumerate(self.__fieldnames):
                 if i:
                     yield (astyle.style_default, ", ")
                 yield (astyle.style_default, f.name())
             yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
 
 class FieldTable(Table, list):
     def __init__(self, *fields):
         Table.__init__(self)
         list.__init__(self)
         self.fields = fields
 
     def add(self, **fields):
         self.append(Fields(self.fields, **fields))
 
     def __xrepr__(self, mode="default"):
         yield (-1, False)
         if mode == "header" or mode == "footer":
             yield (astyle.style_default, self.__class__.__name__)
             yield (astyle.style_default, "(")
             for (i, f) in enumerate(self.__fieldnames):
                 if i:
                     yield (astyle.style_default, ", ")
                 yield (astyle.style_default, f)
             yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "<%s.%s object with fields=%r at 0x%x>" % \
             (self.__class__.__module__, self.__class__.__name__,
              ", ".join(map(repr, self.fields)), id(self))
 
 
 class List(list):
     def __xattrs__(self, mode="default"):
         return xrange(len(self))
 
     def __xrepr__(self, mode="default"):
         yield (-1, False)
         if mode == "header" or mode == "cell" or mode == "footer" or mode == "default":
             yield (astyle.style_default, self.__class__.__name__)
             yield (astyle.style_default, "(")
             for (i, item) in enumerate(self):
                 if i:
                     yield (astyle.style_default, ", ")
                 for part in xrepr(item, "default"):
                     yield part
             yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
 
 class ienv(Table):
     """
     List environment variables.
 
     Example::
 
         >>> ienv
         <class 'IPython.extensions.ipipe.ienv'>
     """
 
     def __iter__(self):
         fields = ("key", "value")
         for (key, value) in os.environ.iteritems():
             yield Fields(fields, key=key, value=value)
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "cell":
             yield (astyle.style_default, "%s()" % self.__class__.__name__)
         else:
             yield (astyle.style_default, repr(self))
 
 
 class ihist(Table):
     """
     IPython input history
 
     Example::
 
         >>> ihist
         <class 'IPython.extensions.ipipe.ihist'>
         >>> ihist(True) # raw mode
         <IPython.extensions.ipipe.ihist object at 0x849602c>  # random
     """
     def __init__(self, raw=True):
         self.raw = raw
 
     def __iter__(self):
         api = ipapi.get()
         if self.raw:
             for line in api.input_hist_raw:
                 yield line.rstrip("\n")
         else:
             for line in api.input_hist:
                 yield line.rstrip("\n")
 
 
 class Alias(object):
     """
     Entry in the alias table
     """
     def __init__(self, name, args, command):
         self.name = name
         self.args = args
         self.command = command
 
     def __xattrs__(self, mode="default"):
         return ("name", "args", "command")
 
 
 class ialias(Table):
     """
     IPython alias list
 
     Example::
 
         >>> ialias
         <class 'IPython.extensions.ipipe.ialias'>
     """
     def __iter__(self):
         api = ipapi.get()
 
         for (name, (args, command)) in api.alias_manager.alias_table.iteritems():
             yield Alias(name, args, command)
 
 
 class icsv(Pipe):
     """
     This ``Pipe`` turns the input (with must be a pipe outputting lines
     or an ``ifile``) into lines of CVS columns.
     """
     def __init__(self, **csvargs):
         """
         Create an ``icsv`` object. ``cvsargs`` will be passed through as
         keyword arguments to ``cvs.reader()``.
         """
         self.csvargs = csvargs
 
     def __iter__(self):
         input = self.input
         if isinstance(input, ifile):
             input = input.open("rb")
         reader = csv.reader(input, **self.csvargs)
         for line in reader:
             yield List(line)
 
     def __xrepr__(self, mode="default"):
         yield (-1, False)
         if mode == "header" or mode == "footer":
             input = getattr(self, "input", None)
             if input is not None:
                 for part in xrepr(input, mode):
                     yield part
                 yield (astyle.style_default, " | ")
             yield (astyle.style_default, "%s(" % self.__class__.__name__)
             for (i, (name, value)) in enumerate(self.csvargs.iteritems()):
                 if i:
                     yield (astyle.style_default, ", ")
                 yield (astyle.style_default, name)
                 yield (astyle.style_default, "=")
                 for part in xrepr(value, "default"):
                     yield part
             yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         args = ", ".join(["%s=%r" % item for item in self.csvargs.iteritems()])
         return "<%s.%s %s at 0x%x>" % \
         (self.__class__.__module__, self.__class__.__name__, args, id(self))
 
 
 class ix(Table):
     """
     Execute a system command and list its output as lines
     (similar to ``os.popen()``).
 
     Examples::
 
         >>> ix("ps x")
         IPython.extensions.ipipe.ix('ps x')
 
         >>> ix("find .") | ifile
         <IPython.extensions.ipipe.ieval expr=<class 'IPython.extensions.ipipe.ifile'> at 0x8509d2c>
         # random
     """
     def __init__(self, cmd):
         self.cmd = cmd
         self._pipeout = None
 
     def __iter__(self):
         (_pipein, self._pipeout) = os.popen4(self.cmd)
         _pipein.close()
         for l in self._pipeout:
             yield l.rstrip("\r\n")
         self._pipeout.close()
         self._pipeout = None
 
     def __del__(self):
         if self._pipeout is not None and not self._pipeout.closed:
             self._pipeout.close()
         self._pipeout = None
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer":
             yield (astyle.style_default,
                    "%s(%r)" % (self.__class__.__name__, self.cmd))
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "%s.%s(%r)" % \
             (self.__class__.__module__, self.__class__.__name__, self.cmd)
 
 
 class ifilter(Pipe):
     """
     Filter an input pipe. Only objects where an expression evaluates to true
     (and doesn't raise an exception) are listed.
 
     Examples::
 
         >>> ils | ifilter("_.isfile() and size>1000")
         >>> igrp | ifilter("len(mem)")
         >>> sys.modules | ifilter(lambda _:_.value is not None)
         # all-random
     """
 
     def __init__(self, expr, globals=None, errors="raiseifallfail"):
         """
         Create an ``ifilter`` object. ``expr`` can be a callable or a string
         containing an expression. ``globals`` will be used as the global
         namespace for calling string expressions (defaulting to IPython's
         user namespace). ``errors`` specifies how exception during evaluation
         of ``expr`` are handled:
 
         ``"drop"``
             drop all items that have errors;
 
         ``"keep"``
             keep all items that have errors;
 
         ``"keeperror"``
             keep the exception of all items that have errors;
 
         ``"raise"``
             raise the exception;
 
         ``"raiseifallfail"``
             raise the first exception if all items have errors; otherwise drop
             those with errors (this is the default).
         """
         self.expr = expr
         self.globals = globals
         self.errors = errors
 
     def __iter__(self):
         if callable(self.expr):
             test = self.expr
         else:
             g = getglobals(self.globals)
             expr = compile(self.expr, "ipipe-expression", "eval")
             def test(item):
                 return eval(expr, g, AttrNamespace(item))
 
         ok = 0
         exc_info = None
         for item in xiter(self.input):
             try:
                 if test(item):
                     yield item
                 ok += 1
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except Exception, exc:
+            except Exception as exc:
                 if self.errors == "drop":
                     pass # Ignore errors
                 elif self.errors == "keep":
                     yield item
                 elif self.errors == "keeperror":
                     yield exc
                 elif self.errors == "raise":
                     raise
                 elif self.errors == "raiseifallfail":
                     if exc_info is None:
                         exc_info = sys.exc_info()
         if not ok and exc_info is not None:
             raise exc_info[0], exc_info[1], exc_info[2]
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer":
             input = getattr(self, "input", None)
             if input is not None:
                 for part in xrepr(input, mode):
                     yield part
                 yield (astyle.style_default, " | ")
             yield (astyle.style_default, "%s(" % self.__class__.__name__)
             for part in xrepr(self.expr, "default"):
                 yield part
             yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "<%s.%s expr=%r at 0x%x>" % \
             (self.__class__.__module__, self.__class__.__name__,
              self.expr, id(self))
 
 
 class ieval(Pipe):
     """
     Evaluate an expression for each object in the input pipe.
 
     Examples::
 
         >>> ils | ieval("_.abspath()")
         # random
         >>> sys.path | ieval(ifile)
         # random
     """
 
     def __init__(self, expr, globals=None, errors="raiseifallfail"):
         """
         Create an ``ieval`` object. ``expr`` can be a callable or a string
         containing an expression. For the meaning of ``globals`` and
         ``errors`` see ``ifilter``.
         """
         self.expr = expr
         self.globals = globals
         self.errors = errors
 
     def __iter__(self):
         if callable(self.expr):
             do = self.expr
         else:
             g = getglobals(self.globals)
             expr = compile(self.expr, "ipipe-expression", "eval")
             def do(item):
                 return eval(expr, g, AttrNamespace(item))
 
         ok = 0
         exc_info = None
         for item in xiter(self.input):
             try:
                 yield do(item)
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except Exception, exc:
+            except Exception as exc:
                 if self.errors == "drop":
                     pass # Ignore errors
                 elif self.errors == "keep":
                     yield item
                 elif self.errors == "keeperror":
                     yield exc
                 elif self.errors == "raise":
                     raise
                 elif self.errors == "raiseifallfail":
                     if exc_info is None:
                         exc_info = sys.exc_info()
         if not ok and exc_info is not None:
             raise exc_info[0], exc_info[1], exc_info[2]
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer":
             input = getattr(self, "input", None)
             if input is not None:
                 for part in xrepr(input, mode):
                     yield part
                 yield (astyle.style_default, " | ")
             yield (astyle.style_default, "%s(" % self.__class__.__name__)
             for part in xrepr(self.expr, "default"):
                 yield part
             yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "<%s.%s expr=%r at 0x%x>" % \
             (self.__class__.__module__, self.__class__.__name__,
              self.expr, id(self))
 
 
 class ienum(Pipe):
     """
     Enumerate the input pipe (i.e. wrap each input object in an object
     with ``index`` and ``object`` attributes).
 
     Examples::
 
         >>> xrange(20) | ieval("_,_*_") | ienum | ifilter("index % 2 == 0") | ieval("object")
     """
     skip_doctest = True
     
     def __iter__(self):
         fields = ("index", "object")
         for (index, object) in enumerate(xiter(self.input)):
             yield Fields(fields, index=index, object=object)
 
 
 class isort(Pipe):
     """
     Sorts the input pipe.
 
     Examples::
 
         >>> ils | isort("size")
         <IPython.extensions.ipipe.isort key='size' reverse=False at 0x849ec2c>
         >>> ils | isort("_.isdir(), _.lower()", reverse=True)
         <IPython.extensions.ipipe.isort key='_.isdir(), _.lower()' reverse=True at 0x849eacc>
         # all-random
     """
 
     def __init__(self, key=None, globals=None, reverse=False):
         """
         Create an ``isort`` object. ``key`` can be a callable or a string
         containing an expression (or ``None`` in which case the items
         themselves will be sorted). If ``reverse`` is true the sort order
         will be reversed. For the meaning of ``globals`` see ``ifilter``.
         """
         self.key = key
         self.globals = globals
         self.reverse = reverse
 
     def __iter__(self):
         if self.key is None:
             items = sorted(xiter(self.input), reverse=self.reverse)
         elif callable(self.key):
             items = sorted(xiter(self.input), key=self.key, reverse=self.reverse)
         else:
             g = getglobals(self.globals)
             key = compile(self.key, "ipipe-expression", "eval")
             def realkey(item):
                 return eval(key, g, AttrNamespace(item))
             items = sorted(xiter(self.input), key=realkey, reverse=self.reverse)
         for item in items:
             yield item
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer":
             input = getattr(self, "input", None)
             if input is not None:
                 for part in xrepr(input, mode):
                     yield part
                 yield (astyle.style_default, " | ")
             yield (astyle.style_default, "%s(" % self.__class__.__name__)
             for part in xrepr(self.key, "default"):
                 yield part
             if self.reverse:
                 yield (astyle.style_default, ", ")
                 for part in xrepr(True, "default"):
                     yield part
             yield (astyle.style_default, ")")
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "<%s.%s key=%r reverse=%r at 0x%x>" % \
             (self.__class__.__module__, self.__class__.__name__,
              self.key, self.reverse, id(self))
 
 
 tab = 3 # for expandtabs()
 
 def _format(field):
     if isinstance(field, str):
         text = repr(field.expandtabs(tab))[1:-1]
     elif isinstance(field, unicode):
         text = repr(field.expandtabs(tab))[2:-1]
     elif isinstance(field, datetime.datetime):
         # Don't use strftime() here, as this requires year >= 1900
         text = "%04d-%02d-%02d %02d:%02d:%02d.%06d" % \
             (field.year, field.month, field.day,
              field.hour, field.minute, field.second, field.microsecond)
     elif isinstance(field, datetime.date):
         text = "%04d-%02d-%02d" % (field.year, field.month, field.day)
     else:
         text = repr(field)
     return text
 
 
 class Display(object):
     class __metaclass__(type):
         def __ror__(self, input):
             return input | self()
 
     def __init__(self, input=None):
         self.input = input
 
     def __ror__(self, input):
         self.input = input
         return self
 
     def display(self):
         pass
 
 
 class iless(Display):
     cmd = "less --quit-if-one-screen --LONG-PROMPT --LINE-NUMBERS --chop-long-lines --shift=8 --RAW-CONTROL-CHARS"
 
     def display(self):
         try:
             pager = os.popen(self.cmd, "w")
             try:
                 for item in xiter(self.input):
                     first = False
                     for attr in xattrs(item, "default"):
                         if first:
                             first = False
                         else:
                             pager.write(" ")
                         attr = upgradexattr(attr)
                         if not isinstance(attr, SelfDescriptor):
                             pager.write(attr.name())
                             pager.write("=")
                         pager.write(str(attr.value(item)))
                     pager.write("\n")
             finally:
                 pager.close()
-        except Exception, exc:
+        except Exception as exc:
             print "%s: %s" % (exc.__class__.__name__, str(exc))
 
 
 class _RedirectIO(object):
     def __init__(self,*args,**kwargs):
         """
         Map the system output streams to self.
         """
         self.stream = StringIO.StringIO()
         self.stdout = sys.stdout
         sys.stdout = self
         self.stderr = sys.stderr
         sys.stderr = self
 
     def write(self, text):
         """
         Write both to screen and to self.
         """
         self.stream.write(text)
         self.stdout.write(text)
         if "\n" in text:
             self.stdout.flush()
 
     def writelines(self, lines):
         """
         Write lines both to screen and to self.
         """
         self.stream.writelines(lines)
         self.stdout.writelines(lines)
         self.stdout.flush()
 
     def restore(self):
         """
         Restore the default system streams.
         """
         self.stdout.flush()
         self.stderr.flush()
         sys.stdout = self.stdout
         sys.stderr = self.stderr
 
 
 class icap(Table):
     """
     Execute a python string and capture any output to stderr/stdout.
 
     Examples::
 
         >>> import time
         >>> icap("for i in range(10): print i, time.sleep(0.1)")
 
     """
     skip_doctest = True
     
     def __init__(self, expr, globals=None):
         self.expr = expr
         self.globals = globals
         log = _RedirectIO()
         try:
             exec(expr, getglobals(globals))
         finally:
             log.restore()
         self.stream = log.stream
 
     def __iter__(self):
         self.stream.seek(0)
         for line in self.stream:
             yield line.rstrip("\r\n")
 
     def __xrepr__(self, mode="default"):
         if mode == "header" or mode == "footer":
             yield (astyle.style_default,
                    "%s(%r)" % (self.__class__.__name__, self.expr))
         else:
             yield (astyle.style_default, repr(self))
 
     def __repr__(self):
         return "%s.%s(%r)" % \
             (self.__class__.__module__, self.__class__.__name__, self.expr)
 
 
 def xformat(value, mode, maxlength):
     align = None
     full = True
     width = 0
     text = astyle.Text()
     for (style, part) in xrepr(value, mode):
         # only consider the first result
         if align is None:
             if isinstance(style, int):
                 # (style, text) really is (alignment, stop)
                 align = style
                 full = part
                 continue
             else:
                 align = -1
                 full = True
         if not isinstance(style, int):
             text.append((style, part))
             width += len(part)
             if width >= maxlength and not full:
                 text.append((astyle.style_ellisis, "..."))
                 width += 3
                 break
     if align is None: # default to left alignment
         align = -1
     return (align, width, text)
 
 
 
 import astyle
 
 class idump(Display):
     # The approximate maximum length of a column entry
     maxattrlength = 200
 
     # Style for column names
     style_header = astyle.Style.fromstr("white:black:bold")
 
     def __init__(self, input=None, *attrs):
         Display.__init__(self, input)
         self.attrs = [upgradexattr(attr) for attr in attrs]
         self.headerpadchar = " "
         self.headersepchar = "|"
         self.datapadchar = " "
         self.datasepchar = "|"
 
     def display(self):
         stream = Term.cout
         allattrs = []
         attrset = set()
         colwidths = {}
         rows = []
         for item in xiter(self.input):
             row = {}
             attrs = self.attrs
             if not attrs:
                 attrs = xattrs(item, "default")
             for attr in attrs:
                 if attr not in attrset:
                     allattrs.append(attr)
                     attrset.add(attr)
                     colwidths[attr] = len(attr.name())
                 try:
                     value = attr.value(item)
                 except (KeyboardInterrupt, SystemExit):
                     raise
-                except Exception, exc:
+                except Exception as exc:
                     value = exc
                 (align, width, text) = xformat(value, "cell", self.maxattrlength)
                 colwidths[attr] = max(colwidths[attr], width)
                 # remember alignment, length and colored parts
                 row[attr] = (align, width, text)
             rows.append(row)
 
         stream.write("\n")
         for (i, attr) in enumerate(allattrs):
             attrname = attr.name()
             self.style_header(attrname).write(stream)
             spc = colwidths[attr] - len(attrname)
             if i < len(colwidths)-1:
                 stream.write(self.headerpadchar*spc)
                 stream.write(self.headersepchar)
         stream.write("\n")
 
         for row in rows:
             for (i, attr) in enumerate(allattrs):
                 (align, width, text) = row[attr]
                 spc = colwidths[attr] - width
                 if align == -1:
                     text.write(stream)
                     if i < len(colwidths)-1:
                         stream.write(self.datapadchar*spc)
                 elif align == 0:
                     spc = colwidths[attr] - width
                     spc1 = spc//2
                     spc2 = spc-spc1
                     stream.write(self.datapadchar*spc1)
                     text.write(stream)
                     if i < len(colwidths)-1:
                         stream.write(self.datapadchar*spc2)
                 else:
                     stream.write(self.datapadchar*spc)
                     text.write(stream)
                 if i < len(colwidths)-1:
                     stream.write(self.datasepchar)
             stream.write("\n")
 
 
 class AttributeDetail(Table):
     """
     ``AttributeDetail`` objects are use for displaying a detailed list of object
     attributes.
     """
     def __init__(self, object, descriptor):
         self.object = object
         self.descriptor = descriptor
 
     def __iter__(self):
         return self.descriptor.iter(self.object)
 
     def name(self):
         return self.descriptor.name()
 
     def attrtype(self):
         return self.descriptor.attrtype(self.object)
 
     def valuetype(self):
         return self.descriptor.valuetype(self.object)
 
     def doc(self):
         return self.descriptor.doc(self.object)
 
     def shortdoc(self):
         return self.descriptor.shortdoc(self.object)
 
     def value(self):
         return self.descriptor.value(self.object)
 
     def __xattrs__(self, mode="default"):
         attrs = ("name()", "attrtype()", "valuetype()", "value()", "shortdoc()")
         if mode == "detail":
             attrs += ("doc()",)
         return attrs
 
     def __xrepr__(self, mode="default"):
         yield (-1, True)
         valuetype = self.valuetype()
         if valuetype is not noitem:
             for part in xrepr(valuetype):
                 yield part
             yield (astyle.style_default, " ")
         yield (astyle.style_default, self.attrtype())
         yield (astyle.style_default, " ")
         yield (astyle.style_default, self.name())
         yield (astyle.style_default, " of ")
         for part in xrepr(self.object):
             yield part
 
 
 try:
     from ibrowse import ibrowse
 except ImportError:
     # No curses (probably Windows) => try igrid
     try:
         from igrid import igrid
     except ImportError:
         # no wx either => use ``idump`` as the default display.
         defaultdisplay = idump
     else:
         defaultdisplay = igrid
         __all__.append("igrid")
 else:
     defaultdisplay = ibrowse
     __all__.append("ibrowse")
 
 
 # If we're running under IPython, register our objects with IPython's
 # generic function ``result_display``, else install a displayhook
 # directly as sys.displayhook
 if generics is not None:
     def display_display(obj):
         return obj.display()
     generics.result_display.when_type(Display)(display_display)
 
     def display_tableobject(obj):
         return display_display(defaultdisplay(obj))
     generics.result_display.when_type(Table)(display_tableobject)
 
     def display_tableclass(obj):
         return display_tableobject(obj())
     generics.result_display.when_type(Table.__metaclass__)(display_tableclass)
 else:
     def installdisplayhook():
         _originalhook = sys.displayhook
         def displayhook(obj):
             if isinstance(obj, type) and issubclass(obj, Table):
                 obj = obj()
             if isinstance(obj, Table):
                 obj = defaultdisplay(obj)
             if isinstance(obj, Display):
                 return obj.display()
             else:
                 _originalhook(obj)
         sys.displayhook = displayhook
     installdisplayhook()

IPython/deathrow/oldfrontend/frontendbase.py

@@ -1,343 +1,343 b''
 # encoding: utf-8
 # -*- test-case-name: IPython.frontend.tests.test_frontendbase -*-
 """
 frontendbase provides an interface and base class for GUI frontends for
 IPython.kernel/IPython.kernel.core.
 
 Frontend implementations will likely want to subclass FrontEndBase.
 
 Author: Barry Wark
 """
 __docformat__ = "restructuredtext en"
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-------------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------------
 # Imports
 #-------------------------------------------------------------------------------
 import string
 import codeop
 import uuid
 
 
 from IPython.frontend.zopeinterface import (
     Interface,
     Attribute,
 )
 from IPython.kernel.core.history import FrontEndHistory
 from IPython.kernel.core.util import Bunch
 
 ##############################################################################
 # TEMPORARY!!! fake configuration, while we decide whether to use tconfig or
 # not
 
 rc = Bunch()
 rc.prompt_in1 = r'In [$number]:  '
 rc.prompt_in2 = r'...'
 rc.prompt_out = r'Out [$number]:  '
 
 ##############################################################################
 # Interface definitions
 ##############################################################################
 
 class IFrontEndFactory(Interface):
     """Factory interface for frontends."""
 
     def __call__(engine=None, history=None):
         """
         Parameters:
         interpreter : IPython.kernel.engineservice.IEngineCore
         """
 
         pass
 
 
 class IFrontEnd(Interface):
     """Interface for frontends. All methods return t.i.d.Deferred"""
 
     Attribute("input_prompt_template", "string.Template instance\
                 substituteable with execute result.")
     Attribute("output_prompt_template", "string.Template instance\
                 substituteable with execute result.")
     Attribute("continuation_prompt_template", "string.Template instance\
                 substituteable with execute result.")
 
     def update_cell_prompt(result, blockID=None):
         """Subclass may override to update the input prompt for a block.
 
         In asynchronous frontends, this method will be called as a
         twisted.internet.defer.Deferred's callback/errback.
         Implementations should thus return result when finished.
 
         Result is a result dict in case of success, and a
         twisted.python.util.failure.Failure in case of an error
         """
 
         pass
 
     def render_result(result):
         """Render the result of an execute call. Implementors may choose the
          method of rendering.
         For example, a notebook-style frontend might render a Chaco plot
         inline.
 
         Parameters:
             result : dict (result of IEngineBase.execute )
                 blockID = result['blockID']
 
         Result:
             Output of frontend rendering
         """
 
         pass
 
     def render_error(failure):
         """Subclasses must override to render the failure.
 
         In asynchronous frontend, since this method will be called as a
         twisted.internet.defer.Deferred's callback. Implementations
         should thus return result when finished.
 
         blockID = failure.blockID
         """
 
         pass
 
     def input_prompt(number=''):
         """Returns the input prompt by subsituting into
         self.input_prompt_template
         """
         pass
 
     def output_prompt(number=''):
         """Returns the output prompt by subsituting into
         self.output_prompt_template
         """
 
         pass
 
     def continuation_prompt():
         """Returns the continuation prompt by subsituting into
         self.continuation_prompt_template
         """
 
         pass
 
     def is_complete(block):
         """Returns True if block is complete, False otherwise."""
 
         pass
 
 
     def get_history_previous(current_block):
         """Returns the block previous in  the history. Saves currentBlock if
         the history_cursor is currently at the end of the input history"""
         pass
 
     def get_history_next():
         """Returns the next block in the history."""
 
         pass
 
     def complete(self, line):
         """Returns the list of possible completions, and the completed
             line.
 
         The input argument is the full line to be completed. This method
         returns both the line completed as much as possible, and the list
         of further possible completions (full words).
         """
         pass
 
 
 ##############################################################################
 # Base class for all the frontends.
 ##############################################################################
 
 class FrontEndBase(object):
     """
     FrontEndBase manages the state tasks for a CLI frontend:
         - Input and output history management
         - Input/continuation and output prompt generation
 
     Some issues (due to possibly unavailable engine):
         - How do we get the current cell number for the engine?
         - How do we handle completions?
     """
 
     history_cursor = 0
 
     input_prompt_template = string.Template(rc.prompt_in1)
     output_prompt_template = string.Template(rc.prompt_out)
     continuation_prompt_template = string.Template(rc.prompt_in2)
 
     def __init__(self, shell=None, history=None):
         self.shell = shell
         if history is None:
                 self.history = FrontEndHistory(input_cache=[''])
         else:
             self.history = history
 
 
     def input_prompt(self, number=''):
         """Returns the current input prompt
 
         It would be great to use ipython1.core.prompts.Prompt1 here
         """
         return self.input_prompt_template.safe_substitute({'number':number})
 
 
     def continuation_prompt(self):
         """Returns the current continuation prompt"""
 
         return self.continuation_prompt_template.safe_substitute()
 
     def output_prompt(self, number=''):
         """Returns the output prompt for result"""
 
         return self.output_prompt_template.safe_substitute({'number':number})
 
 
     def is_complete(self, block):
         """Determine if block is complete.
 
         Parameters
         block : string
 
         Result
         True if block can be sent to the engine without compile errors.
         False otherwise.
         """
 
         try:
             is_complete = codeop.compile_command(block.rstrip() + '\n\n',
                             "<string>", "exec")
         except:
             return False
 
         lines = block.split('\n')
         return ((is_complete is not None)
                     and (len(lines)==1 or str(lines[-1])==''))
 
 
     def execute(self, block, blockID=None):
         """Execute the block and return the result.
 
         Parameters:
             block : {str, AST}
             blockID : any
                 Caller may provide an ID to identify this block.
                 result['blockID'] := blockID
 
         Result:
             Deferred result of self.interpreter.execute
         """
 
         if(not self.is_complete(block)):
             raise Exception("Block is not compilable")
 
         if(blockID == None):
             blockID = uuid.uuid4()
 
         try:
             result = self.shell.execute(block)
-        except Exception,e:
+        except Exception as e:
             e = self._add_block_id_for_failure(e, blockID=blockID)
             e = self.update_cell_prompt(e, blockID=blockID)
             e = self.render_error(e)
         else:
             result = self._add_block_id_for_result(result, blockID=blockID)
             result = self.update_cell_prompt(result, blockID=blockID)
             result = self.render_result(result)
 
         return result
 
 
     def _add_block_id_for_result(self, result, blockID):
         """Add the blockID to result or failure. Unfortunatley, we have to
         treat failures differently than result dicts.
         """
 
         result['blockID'] = blockID
 
         return result
 
     def _add_block_id_for_failure(self, failure, blockID):
         """_add_block_id_for_failure"""
         failure.blockID = blockID
         return failure
 
 
     def _add_history(self, result, block=None):
         """Add block to the history"""
 
         assert(block != None)
         self.history.add_items([block])
         self.history_cursor += 1
 
         return result
 
 
     def get_history_previous(self, current_block):
         """ Returns previous history string and decrement history cursor.
         """
         command = self.history.get_history_item(self.history_cursor - 1)
 
         if command is not None:
             if(self.history_cursor+1 == len(self.history.input_cache)):
                 self.history.input_cache[self.history_cursor] = current_block
             self.history_cursor -= 1
         return command
 
 
     def get_history_next(self):
         """ Returns next history string and increment history cursor.
         """
         command = self.history.get_history_item(self.history_cursor+1)
 
         if command is not None:
             self.history_cursor += 1
         return command
 
     ###
     # Subclasses probably want to override these methods...
     ###
 
     def update_cell_prompt(self, result, blockID=None):
         """Subclass may override to update the input prompt for a block.
 
         This method only really makes sens in asyncrhonous frontend.
         Since this method will be called as a
         twisted.internet.defer.Deferred's callback, implementations should
         return result when finished.
         """
 
         raise NotImplementedError
 
 
     def render_result(self, result):
         """Subclasses must override to render result.
 
         In asynchronous frontends, this method will be called as a
         twisted.internet.defer.Deferred's callback. Implementations
         should thus return result when finished.
         """
 
         raise NotImplementedError
 
 
     def render_error(self, failure):
         """Subclasses must override to render the failure.
 
         In asynchronous frontends, this method will be called as a
         twisted.internet.defer.Deferred's callback. Implementations
         should thus return result when finished.
         """
 
         raise NotImplementedError
 

IPython/deathrow/oldfrontend/linefrontendbase.py

@@ -1,373 +1,373 b''
 """
 Base front end class for all line-oriented frontends, rather than
 block-oriented.
 
 Currently this focuses on synchronous frontends.
 """
 __docformat__ = "restructuredtext en"
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-------------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------------
 # Imports
 #-------------------------------------------------------------------------------
 import re
 
 import sys
 import codeop
 
 from frontendbase import FrontEndBase
 from IPython.kernel.core.interpreter import Interpreter
 
 def common_prefix(strings):
     """ Given a list of strings, return the common prefix between all
         these strings.
     """
     ref = strings[0]
     prefix = ''
     for size in range(len(ref)):
         test_prefix = ref[:size+1]
         for string in strings[1:]:
             if not string.startswith(test_prefix):
                 return prefix
         prefix = test_prefix
 
     return prefix
 
 #-----------------------------------------------------------------------------
 # Base class for the line-oriented front ends
 #-----------------------------------------------------------------------------
 
 class LineFrontEndBase(FrontEndBase):
     """ Concrete implementation of the FrontEndBase class. This is meant
     to be the base class behind all the frontend that are line-oriented,
     rather than block-oriented.
     """
 
     # We need to keep the prompt number, to be able to increment
     # it when there is an exception.
     prompt_number = 1
 
     # We keep a reference to the last result: it helps testing and
     # programatic control of the frontend.
     last_result = dict(number=0)
 
     # The last prompt displayed. Useful for continuation prompts.
     last_prompt = ''
 
     # The input buffer being edited
     input_buffer = ''
 
     # Set to true for debug output
     debug = False
 
     # A banner to print at startup
     banner = None
 
     #--------------------------------------------------------------------------
     # FrontEndBase interface
     #--------------------------------------------------------------------------
 
     def __init__(self, shell=None, history=None, banner=None, *args, **kwargs):
         if shell is None:
             shell = Interpreter()
         FrontEndBase.__init__(self, shell=shell, history=history)
 
         if banner is not None:
             self.banner = banner
 
     def start(self):
         """ Put the frontend in a state where it is ready for user
             interaction.
         """
         if self.banner is not None:
             self.write(self.banner, refresh=False)
 
         self.new_prompt(self.input_prompt_template.substitute(number=1))
 
 
     def complete(self, line):
         """Complete line in engine's user_ns
 
         Parameters
         ----------
         line : string
 
         Returns
         -------
         The replacement for the line and the list of possible completions.
         """
         completions = self.shell.complete(line)
         complete_sep =  re.compile('[\s\{\}\[\]\(\)\=]')
         if completions:
             prefix = common_prefix(completions)
             residual = complete_sep.split(line)[:-1]
             line = line[:-len(residual)] + prefix
         return line, completions
 
 
     def render_result(self, result):
         """ Frontend-specific rendering of the result of a calculation
         that has been sent to an engine.
         """
         if 'stdout' in result and result['stdout']:
             self.write('\n' + result['stdout'])
         if 'display' in result and result['display']:
             self.write("%s%s\n" % (
                             self.output_prompt_template.substitute(
                                     number=result['number']),
                             result['display']['pprint']
                             ) )
 
 
     def render_error(self, failure):
         """ Frontend-specific rendering of error.
         """
         self.write('\n\n'+str(failure)+'\n\n')
         return failure
 
 
     def is_complete(self, string):
         """ Check if a string forms a complete, executable set of
         commands.
 
         For the line-oriented frontend, multi-line code is not executed
         as soon as it is complete: the users has to enter two line
         returns.
         """
         if string in ('', '\n'):
             # Prefiltering, eg through ipython0, may return an empty
             # string although some operations have been accomplished. We
             # thus want to consider an empty string as a complete
             # statement.
             return True
         elif ( len(self.input_buffer.split('\n'))>2
                         and not re.findall(r"\n[\t ]*\n[\t ]*$", string)):
             return False
         else:
             self.capture_output()
             try:
                 # Add line returns here, to make sure that the statement is
                 # complete (except if '\' was used).
                 # This should probably be done in a different place (like
                 # maybe 'prefilter_input' method? For now, this works.
                 clean_string = string.rstrip('\n')
                 if not clean_string.endswith('\\'): clean_string +='\n\n'
                 is_complete = codeop.compile_command(clean_string,
                             "<string>", "exec")
                 self.release_output()
-            except Exception, e:
+            except Exception as e:
                 # XXX: Hack: return True so that the
                 # code gets executed and the error captured.
                 is_complete = True
             return is_complete
 
 
     def write(self, string, refresh=True):
         """ Write some characters to the display.
 
             Subclass should overide this method.
 
             The refresh keyword argument is used in frontends with an
             event loop, to choose whether the write should trigget an UI
             refresh, and thus be syncrhonous, or not.
         """
         print >>sys.__stderr__, string
 
 
     def execute(self, python_string, raw_string=None):
         """ Stores the raw_string in the history, and sends the
         python string to the interpreter.
         """
         if raw_string is None:
             raw_string = python_string
         # Create a false result, in case there is an exception
         self.last_result = dict(number=self.prompt_number)
 
         try:
             try:
                 self.history.input_cache[-1] = raw_string.rstrip()
                 result = self.shell.execute(python_string)
                 self.last_result = result
                 self.render_result(result)
             except:
                 self.show_traceback()
         finally:
             self.after_execute()
 
 
     #--------------------------------------------------------------------------
     # LineFrontEndBase interface
     #--------------------------------------------------------------------------
 
     def prefilter_input(self, string):
         """ Prefilter the input to turn it in valid python.
         """
         string = string.replace('\r\n', '\n')
         string = string.replace('\t', 4*' ')
         # Clean the trailing whitespace
         string = '\n'.join(l.rstrip()  for l in string.split('\n'))
         return string
 
 
     def after_execute(self):
         """ All the operations required after an execution to put the
             terminal back in a shape where it is usable.
         """
         self.prompt_number += 1
         self.new_prompt(self.input_prompt_template.substitute(
                             number=(self.last_result['number'] + 1)))
         # Start a new empty history entry
         self._add_history(None, '')
         self.history_cursor = len(self.history.input_cache) - 1
 
 
     def complete_current_input(self):
         """ Do code completion on current line.
         """
         if self.debug:
             print >>sys.__stdout__, "complete_current_input",
         line = self.input_buffer
         new_line, completions = self.complete(line)
         if len(completions)>1:
             self.write_completion(completions, new_line=new_line)
         elif not line == new_line:
             self.input_buffer = new_line
         if self.debug:
             print >>sys.__stdout__, 'line', line
             print >>sys.__stdout__, 'new_line', new_line
             print >>sys.__stdout__, completions
 
 
     def get_line_width(self):
         """ Return the width of the line in characters.
         """
         return 80
 
 
     def write_completion(self, possibilities, new_line=None):
         """ Write the list of possible completions.
 
             new_line is the completed input line that should be displayed
             after the completion are writen. If None, the input_buffer
             before the completion is used.
         """
         if new_line is None:
             new_line = self.input_buffer
 
         self.write('\n')
         max_len = len(max(possibilities, key=len)) + 1
 
         # Now we check how much symbol we can put on a line...
         chars_per_line = self.get_line_width()
         symbols_per_line = max(1, chars_per_line/max_len)
 
         pos = 1
         completion_string = []
         for symbol in possibilities:
             if pos < symbols_per_line:
                 completion_string.append(symbol.ljust(max_len))
                 pos += 1
             else:
                 completion_string.append(symbol.rstrip() + '\n')
                 pos = 1
         self.write(''.join(completion_string))
         self.new_prompt(self.input_prompt_template.substitute(
                             number=self.last_result['number'] + 1))
         self.input_buffer = new_line
 
 
     def new_prompt(self, prompt):
         """ Prints a prompt and starts a new editing buffer.
 
             Subclasses should use this method to make sure that the
             terminal is put in a state favorable for a new line
             input.
         """
         self.input_buffer = ''
         self.write(prompt)
 
 
     def continuation_prompt(self):
         """Returns the current continuation prompt.
         """
         return ("."*(len(self.last_prompt)-2) + ': ')
 
 
     def execute_command(self, command, hidden=False):
         """ Execute a command, not only in the model, but also in the
             view, if any.
         """
         return self.shell.execute(command)
 
     #--------------------------------------------------------------------------
     # Private API
     #--------------------------------------------------------------------------
 
     def _on_enter(self, new_line_pos=0):
         """ Called when the return key is pressed in a line editing
             buffer.
 
             Parameters
             ----------
             new_line_pos : integer, optional
                 Position of the new line to add, starting from the
                 end (0 adds a new line after the last line, -1 before
                 the last line...)
 
             Returns
             -------
             True if execution is triggered
         """
         current_buffer = self.input_buffer
         # XXX: This string replace is ugly, but there should be no way it
         # fails.
         prompt_less_buffer = re.sub('^' + self.continuation_prompt(),
                 '', current_buffer).replace('\n' + self.continuation_prompt(),
                                             '\n')
         cleaned_buffer = self.prefilter_input(prompt_less_buffer)
         if self.is_complete(cleaned_buffer):
             self.execute(cleaned_buffer, raw_string=current_buffer)
             return True
         else:
             # Start a new line.
             new_line_pos = -new_line_pos
             lines = current_buffer.split('\n')[:-1]
             prompt_less_lines = prompt_less_buffer.split('\n')
             # Create the new line, with the continuation prompt, and the
             # same amount of indent than the line above it.
             new_line = self.continuation_prompt() + \
                   self._get_indent_string('\n'.join(
                                     prompt_less_lines[:new_line_pos-1]))
             if len(lines) == 1:
                 # We are starting a first continuation line. Indent it.
                 new_line += '\t'
             elif current_buffer[:-1].split('\n')[-1].rstrip().endswith(':'):
                 # The last line ends with ":", autoindent the new line.
                 new_line += '\t'
 
             if new_line_pos == 0:
                 lines.append(new_line)
             else:
                 lines.insert(new_line_pos, new_line)
             self.input_buffer = '\n'.join(lines)
 
 
     def _get_indent_string(self, string):
         """ Return the string of whitespace that prefixes a line. Used to
         add the right amount of indendation when creating a new line.
         """
         string = string.replace('\t', ' '*4)
         string = string.split('\n')[-1]
         indent_chars = len(string) - len(string.lstrip())
         indent_string = '\t'*(indent_chars // 4) + \
                             ' '*(indent_chars % 4)
 
         return indent_string