allow_none=False by default for Type and Instance

IPython/config/application.py

@@ -1,622 +1,622 b''
 # encoding: utf-8
 """A base class for a configurable application."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import json
 import logging
 import os
 import re
 import sys
 from copy import deepcopy
 from collections import defaultdict
 
 from decorator import decorator
 
 from IPython.config.configurable import SingletonConfigurable
 from IPython.config.loader import (
     KVArgParseConfigLoader, PyFileConfigLoader, Config, ArgumentError, ConfigFileNotFound, JSONFileConfigLoader
 )
 
 from IPython.utils.traitlets import (
     Unicode, List, Enum, Dict, Instance, TraitError
 )
 from IPython.utils.importstring import import_item
 from IPython.utils.text import indent, wrap_paragraphs, dedent
 from IPython.utils import py3compat
 from IPython.utils.py3compat import string_types, iteritems
 
 #-----------------------------------------------------------------------------
 # Descriptions for the various sections
 #-----------------------------------------------------------------------------
 
 # merge flags&aliases into options
 option_description = """
 Arguments that take values are actually convenience aliases to full
 Configurables, whose aliases are listed on the help line. For more information
 on full configurables, see '--help-all'.
 """.strip() # trim newlines of front and back
 
 keyvalue_description = """
 Parameters are set from command-line arguments of the form:
 `--Class.trait=value`.
 This line is evaluated in Python, so simple expressions are allowed, e.g.::
 `--C.a='range(3)'` For setting C.a=[0,1,2].
 """.strip() # trim newlines of front and back
 
 # sys.argv can be missing, for example when python is embedded. See the docs
 # for details: http://docs.python.org/2/c-api/intro.html#embedding-python
 if not hasattr(sys, "argv"):
     sys.argv = [""]
 
 subcommand_description = """
 Subcommands are launched as `{app} cmd [args]`. For information on using
 subcommand 'cmd', do: `{app} cmd -h`.
 """
 # get running program name
 
 #-----------------------------------------------------------------------------
 # Application class
 #-----------------------------------------------------------------------------
 
 @decorator
 def catch_config_error(method, app, *args, **kwargs):
     """Method decorator for catching invalid config (Trait/ArgumentErrors) during init.
 
     On a TraitError (generally caused by bad config), this will print the trait's
     message, and exit the app.
     
     For use on init methods, to prevent invoking excepthook on invalid input.
     """
     try:
         return method(app, *args, **kwargs)
     except (TraitError, ArgumentError) as e:
         app.print_help()
         app.log.fatal("Bad config encountered during initialization:")
         app.log.fatal(str(e))
         app.log.debug("Config at the time: %s", app.config)
         app.exit(1)
 
 
 class ApplicationError(Exception):
     pass
 
 class LevelFormatter(logging.Formatter):
     """Formatter with additional `highlevel` record
     
     This field is empty if log level is less than highlevel_limit,
     otherwise it is formatted with self.highlevel_format.
     
     Useful for adding 'WARNING' to warning messages,
     without adding 'INFO' to info, etc.
     """
     highlevel_limit = logging.WARN
     highlevel_format = " %(levelname)s |"
     
     def format(self, record):
         if record.levelno >= self.highlevel_limit:
             record.highlevel = self.highlevel_format % record.__dict__
         else:
             record.highlevel = ""
         return super(LevelFormatter, self).format(record)
             
 
 class Application(SingletonConfigurable):
     """A singleton application with full configuration support."""
 
     # The name of the application, will usually match the name of the command
     # line application
     name = Unicode(u'application')
 
     # The description of the application that is printed at the beginning
     # of the help.
     description = Unicode(u'This is an application.')
     # default section descriptions
     option_description = Unicode(option_description)
     keyvalue_description = Unicode(keyvalue_description)
     subcommand_description = Unicode(subcommand_description)
     
     python_config_loader_class = PyFileConfigLoader
     json_config_loader_class = JSONFileConfigLoader
 
     # The usage and example string that goes at the end of the help string.
     examples = Unicode()
 
     # A sequence of Configurable subclasses whose config=True attributes will
     # be exposed at the command line.
     classes = []
     @property
     def _help_classes(self):
         """Define `App.help_classes` if CLI classes should differ from config file classes"""
         return getattr(self, 'help_classes', self.classes)
     
     @property
     def _config_classes(self):
         """Define `App.config_classes` if config file classes should differ from CLI classes."""
         return getattr(self, 'config_classes', self.classes)
 
     # The version string of this application.
     version = Unicode(u'0.0')
     
     # the argv used to initialize the application
     argv = List()
 
     # The log level for the application
     log_level = Enum((0,10,20,30,40,50,'DEBUG','INFO','WARN','ERROR','CRITICAL'),
                     default_value=logging.WARN,
                     config=True,
                     help="Set the log level by value or name.")
     def _log_level_changed(self, name, old, new):
         """Adjust the log level when log_level is set."""
         if isinstance(new, string_types):
             new = getattr(logging, new)
             self.log_level = new
         self.log.setLevel(new)
     
     _log_formatter_cls = LevelFormatter
     
     log_datefmt = Unicode("%Y-%m-%d %H:%M:%S", config=True,
         help="The date format used by logging formatters for %(asctime)s"
     )
     def _log_datefmt_changed(self, name, old, new):
         self._log_format_changed('log_format', self.log_format, self.log_format)
     
     log_format = Unicode("[%(name)s]%(highlevel)s %(message)s", config=True,
         help="The Logging format template",
     )
     def _log_format_changed(self, name, old, new):
         """Change the log formatter when log_format is set."""
         _log_handler = self.log.handlers[0]
         _log_formatter = self._log_formatter_cls(fmt=new, datefmt=self.log_datefmt)
         _log_handler.setFormatter(_log_formatter)
     
 
-    log = Instance(logging.Logger)
+    log = Instance(logging.Logger, allow_none=True)
     def _log_default(self):
         """Start logging for this application.
 
         The default is to log to stderr using a StreamHandler, if no default
         handler already exists.  The log level starts at logging.WARN, but this
         can be adjusted by setting the ``log_level`` attribute.
         """
         log = logging.getLogger(self.__class__.__name__)
         log.setLevel(self.log_level)
         log.propagate = False
         _log = log # copied from Logger.hasHandlers() (new in Python 3.2)
         while _log:
             if _log.handlers:
                 return log
             if not _log.propagate:
                 break
             else:
                 _log = _log.parent
         if sys.executable.endswith('pythonw.exe'):
             # this should really go to a file, but file-logging is only
             # hooked up in parallel applications
             _log_handler = logging.StreamHandler(open(os.devnull, 'w'))
         else:
             _log_handler = logging.StreamHandler()
         _log_formatter = self._log_formatter_cls(fmt=self.log_format, datefmt=self.log_datefmt)
         _log_handler.setFormatter(_log_formatter)
         log.addHandler(_log_handler)
         return log
 
     # the alias map for configurables
     aliases = Dict({'log-level' : 'Application.log_level'})
 
     # flags for loading Configurables or store_const style flags
     # flags are loaded from this dict by '--key' flags
     # this must be a dict of two-tuples, the first element being the Config/dict
     # and the second being the help string for the flag
     flags = Dict()
     def _flags_changed(self, name, old, new):
         """ensure flags dict is valid"""
         for key,value in iteritems(new):
             assert len(value) == 2, "Bad flag: %r:%s"%(key,value)
             assert isinstance(value[0], (dict, Config)), "Bad flag: %r:%s"%(key,value)
             assert isinstance(value[1], string_types), "Bad flag: %r:%s"%(key,value)
 
 
     # subcommands for launching other applications
     # if this is not empty, this will be a parent Application
     # this must be a dict of two-tuples,
     # the first element being the application class/import string
     # and the second being the help string for the subcommand
     subcommands = Dict()
     # parse_command_line will initialize a subapp, if requested
     subapp = Instance('IPython.config.application.Application', allow_none=True)
 
     # extra command-line arguments that don't set config values
     extra_args = List(Unicode)
 
 
     def __init__(self, **kwargs):
         SingletonConfigurable.__init__(self, **kwargs)
         # Ensure my class is in self.classes, so my attributes appear in command line
         # options and config files.
         if self.__class__ not in self.classes:
             self.classes.insert(0, self.__class__)
 
     def _config_changed(self, name, old, new):
         SingletonConfigurable._config_changed(self, name, old, new)
         self.log.debug('Config changed:')
         self.log.debug(repr(new))
 
     @catch_config_error
     def initialize(self, argv=None):
         """Do the basic steps to configure me.
 
         Override in subclasses.
         """
         self.parse_command_line(argv)
 
 
     def start(self):
         """Start the app mainloop.
 
         Override in subclasses.
         """
         if self.subapp is not None:
             return self.subapp.start()
 
     def print_alias_help(self):
         """Print the alias part of the help."""
         if not self.aliases:
             return
 
         lines = []
         classdict = {}
         for cls in self._help_classes:
             # include all parents (up to, but excluding Configurable) in available names
             for c in cls.mro()[:-3]:
                 classdict[c.__name__] = c
 
         for alias, longname in iteritems(self.aliases):
             classname, traitname = longname.split('.',1)
             cls = classdict[classname]
 
             trait = cls.class_traits(config=True)[traitname]
             help = cls.class_get_trait_help(trait).splitlines()
             # reformat first line
             help[0] = help[0].replace(longname, alias) + ' (%s)'%longname
             if len(alias) == 1:
                 help[0] = help[0].replace('--%s='%alias, '-%s '%alias)
             lines.extend(help)
         # lines.append('')
         print(os.linesep.join(lines))
 
     def print_flag_help(self):
         """Print the flag part of the help."""
         if not self.flags:
             return
 
         lines = []
         for m, (cfg,help) in iteritems(self.flags):
             prefix = '--' if len(m) > 1 else '-'
             lines.append(prefix+m)
             lines.append(indent(dedent(help.strip())))
         # lines.append('')
         print(os.linesep.join(lines))
 
     def print_options(self):
         if not self.flags and not self.aliases:
             return
         lines = ['Options']
         lines.append('-'*len(lines[0]))
         lines.append('')
         for p in wrap_paragraphs(self.option_description):
             lines.append(p)
             lines.append('')
         print(os.linesep.join(lines))
         self.print_flag_help()
         self.print_alias_help()
         print()
 
     def print_subcommands(self):
         """Print the subcommand part of the help."""
         if not self.subcommands:
             return
 
         lines = ["Subcommands"]
         lines.append('-'*len(lines[0]))
         lines.append('')
         for p in wrap_paragraphs(self.subcommand_description.format(
                     app=self.name)):
             lines.append(p)
             lines.append('')
         for subc, (cls, help) in iteritems(self.subcommands):
             lines.append(subc)
             if help:
                 lines.append(indent(dedent(help.strip())))
         lines.append('')
         print(os.linesep.join(lines))
 
     def print_help(self, classes=False):
         """Print the help for each Configurable class in self.classes.
 
         If classes=False (the default), only flags and aliases are printed.
         """
         self.print_description()
         self.print_subcommands()
         self.print_options()
 
         if classes:
             help_classes = self._help_classes
             if help_classes:
                 print("Class parameters")
                 print("----------------")
                 print()
                 for p in wrap_paragraphs(self.keyvalue_description):
                     print(p)
                     print()
 
             for cls in help_classes:
                 cls.class_print_help()
                 print()
         else:
             print("To see all available configurables, use `--help-all`")
             print()
 
         self.print_examples()
 
 
     def print_description(self):
         """Print the application description."""
         for p in wrap_paragraphs(self.description):
             print(p)
             print()
 
     def print_examples(self):
         """Print usage and examples.
 
         This usage string goes at the end of the command line help string
         and should contain examples of the application's usage.
         """
         if self.examples:
             print("Examples")
             print("--------")
             print()
             print(indent(dedent(self.examples.strip())))
             print()
 
     def print_version(self):
         """Print the version string."""
         print(self.version)
 
     def update_config(self, config):
         """Fire the traits events when the config is updated."""
         # Save a copy of the current config.
         newconfig = deepcopy(self.config)
         # Merge the new config into the current one.
         newconfig.merge(config)
         # Save the combined config as self.config, which triggers the traits
         # events.
         self.config = newconfig
 
     @catch_config_error
     def initialize_subcommand(self, subc, argv=None):
         """Initialize a subcommand with argv."""
         subapp,help = self.subcommands.get(subc)
 
         if isinstance(subapp, string_types):
             subapp = import_item(subapp)
 
         # clear existing instances
         self.__class__.clear_instance()
         # instantiate
         self.subapp = subapp.instance(config=self.config)
         # and initialize subapp
         self.subapp.initialize(argv)
     
     def flatten_flags(self):
         """flatten flags and aliases, so cl-args override as expected.
         
         This prevents issues such as an alias pointing to InteractiveShell,
         but a config file setting the same trait in TerminalInteraciveShell
         getting inappropriate priority over the command-line arg.
 
         Only aliases with exactly one descendent in the class list
         will be promoted.
         
         """
         # build a tree of classes in our list that inherit from a particular
         # it will be a dict by parent classname of classes in our list
         # that are descendents
         mro_tree = defaultdict(list)
         for cls in self._help_classes:
             clsname = cls.__name__
             for parent in cls.mro()[1:-3]:
                 # exclude cls itself and Configurable,HasTraits,object
                 mro_tree[parent.__name__].append(clsname)
         # flatten aliases, which have the form:
         # { 'alias' : 'Class.trait' }
         aliases = {}
         for alias, cls_trait in iteritems(self.aliases):
             cls,trait = cls_trait.split('.',1)
             children = mro_tree[cls]
             if len(children) == 1:
                 # exactly one descendent, promote alias
                 cls = children[0]
             aliases[alias] = '.'.join([cls,trait])
         
         # flatten flags, which are of the form:
         # { 'key' : ({'Cls' : {'trait' : value}}, 'help')}
         flags = {}
         for key, (flagdict, help) in iteritems(self.flags):
             newflag = {}
             for cls, subdict in iteritems(flagdict):
                 children = mro_tree[cls]
                 # exactly one descendent, promote flag section
                 if len(children) == 1:
                     cls = children[0]
                 newflag[cls] = subdict
             flags[key] = (newflag, help)
         return flags, aliases
 
     @catch_config_error
     def parse_command_line(self, argv=None):
         """Parse the command line arguments."""
         argv = sys.argv[1:] if argv is None else argv
         self.argv = [ py3compat.cast_unicode(arg) for arg in argv ]
         
         if argv and argv[0] == 'help':
             # turn `ipython help notebook` into `ipython notebook -h`
             argv = argv[1:] + ['-h']
 
         if self.subcommands and len(argv) > 0:
             # we have subcommands, and one may have been specified
             subc, subargv = argv[0], argv[1:]
             if re.match(r'^\w(\-?\w)*$', subc) and subc in self.subcommands:
                 # it's a subcommand, and *not* a flag or class parameter
                 return self.initialize_subcommand(subc, subargv)
 
         # Arguments after a '--' argument are for the script IPython may be
         # about to run, not IPython iteslf. For arguments parsed here (help and
         # version), we want to only search the arguments up to the first
         # occurrence of '--', which we're calling interpreted_argv.
         try:
             interpreted_argv = argv[:argv.index('--')]
         except ValueError:
             interpreted_argv = argv
 
         if any(x in interpreted_argv for x in ('-h', '--help-all', '--help')):
             self.print_help('--help-all' in interpreted_argv)
             self.exit(0)
 
         if '--version' in interpreted_argv or '-V' in interpreted_argv:
             self.print_version()
             self.exit(0)
         
         # flatten flags&aliases, so cl-args get appropriate priority:
         flags,aliases = self.flatten_flags()
         loader = KVArgParseConfigLoader(argv=argv, aliases=aliases,
                                         flags=flags, log=self.log)
         config = loader.load_config()
         self.update_config(config)
         # store unparsed args in extra_args
         self.extra_args = loader.extra_args
 
     @classmethod
     def _load_config_files(cls, basefilename, path=None, log=None):
         """Load config files (py,json) by filename and path.
 
         yield each config object in turn.
         """
         
         if not isinstance(path, list):
             path = [path]
         for path in path[::-1]:
             # path list is in descending priority order, so load files backwards:
             pyloader = cls.python_config_loader_class(basefilename+'.py', path=path, log=log)
             jsonloader = cls.json_config_loader_class(basefilename+'.json', path=path, log=log)
             config = None
             for loader in [pyloader, jsonloader]:
                 try:
                     config = loader.load_config()
                 except ConfigFileNotFound:
                     pass
                 except Exception:
                     # try to get the full filename, but it will be empty in the
                     # unlikely event that the error raised before filefind finished
                     filename = loader.full_filename or basefilename
                     # problem while running the file
                     if log:
                         log.error("Exception while loading config file %s",
                                 filename, exc_info=True)
                 else:
                     if log:
                         log.debug("Loaded config file: %s", loader.full_filename)
                 if config:
                      yield config
 
         raise StopIteration
 
 
     @catch_config_error
     def load_config_file(self, filename, path=None):
         """Load config files by filename and path."""
         filename, ext = os.path.splitext(filename)
         loaded = []
         for config in self._load_config_files(filename, path=path, log=self.log):
             loaded.append(config)
             self.update_config(config)
         if len(loaded) > 1:
             collisions = loaded[0].collisions(loaded[1])
             if collisions:
                 self.log.warn("Collisions detected in {0}.py and {0}.json config files."
                               " {0}.json has higher priority: {1}".format(
                               filename, json.dumps(collisions, indent=2),
                 ))
 
 
     def generate_config_file(self):
         """generate default config file from Configurables"""
         lines = ["# Configuration file for %s." % self.name]
         lines.append('')
         for cls in self._config_classes:
             lines.append(cls.class_config_section())
         return '\n'.join(lines)
 
     def exit(self, exit_status=0):
         self.log.debug("Exiting application: %s" % self.name)
         sys.exit(exit_status)
 
     @classmethod
     def launch_instance(cls, argv=None, **kwargs):
         """Launch a global instance of this Application
         
         If a global instance already exists, this reinitializes and starts it
         """
         app = cls.instance(**kwargs)
         app.initialize(argv)
         app.start()
 
 #-----------------------------------------------------------------------------
 # utility functions, for convenience
 #-----------------------------------------------------------------------------
 
 def boolean_flag(name, configurable, set_help='', unset_help=''):
     """Helper for building basic --trait, --no-trait flags.
 
     Parameters
     ----------
 
     name : str
         The name of the flag.
     configurable : str
         The 'Class.trait' string of the trait to be set/unset with the flag
     set_help : unicode
         help string for --name flag
     unset_help : unicode
         help string for --no-name flag
 
     Returns
     -------
 
     cfg : dict
         A dict with two keys: 'name', and 'no-name', for setting and unsetting
         the trait, respectively.
     """
     # default helpstrings
     set_help = set_help or "set %s=True"%configurable
     unset_help = unset_help or "set %s=False"%configurable
 
     cls,trait = configurable.split('.')
 
     setter = {cls : {trait : True}}
     unsetter = {cls : {trait : False}}
     return {name : (setter, set_help), 'no-'+name : (unsetter, unset_help)}
 
 
 def get_config():
     """Get the config object for the global Application instance, if there is one
     
     otherwise return an empty config object
     """
     if Application.initialized():
         return Application.instance().config
     else:
         return Config()

IPython/config/configurable.py

@@ -1,380 +1,380 b''
 # encoding: utf-8
 """A base class for objects that are configurable."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import logging
 from copy import deepcopy
 
 from .loader import Config, LazyConfigValue
 from IPython.utils.traitlets import HasTraits, Instance
 from IPython.utils.text import indent, wrap_paragraphs
 from IPython.utils.py3compat import iteritems
 
 
 #-----------------------------------------------------------------------------
 # Helper classes for Configurables
 #-----------------------------------------------------------------------------
 
 
 class ConfigurableError(Exception):
     pass
 
 
 class MultipleInstanceError(ConfigurableError):
     pass
 
 #-----------------------------------------------------------------------------
 # Configurable implementation
 #-----------------------------------------------------------------------------
 
 class Configurable(HasTraits):
 
     config = Instance(Config, (), {})
-    parent = Instance('IPython.config.configurable.Configurable')
+    parent = Instance('IPython.config.configurable.Configurable', allow_none=True)
 
     def __init__(self, **kwargs):
         """Create a configurable given a config config.
 
         Parameters
         ----------
         config : Config
             If this is empty, default values are used. If config is a
             :class:`Config` instance, it will be used to configure the
             instance.
         parent : Configurable instance, optional
             The parent Configurable instance of this object.
 
         Notes
         -----
         Subclasses of Configurable must call the :meth:`__init__` method of
         :class:`Configurable` *before* doing anything else and using
         :func:`super`::
 
             class MyConfigurable(Configurable):
                 def __init__(self, config=None):
                     super(MyConfigurable, self).__init__(config=config)
                     # Then any other code you need to finish initialization.
 
         This ensures that instances will be configured properly.
         """
         parent = kwargs.pop('parent', None)
         if parent is not None:
             # config is implied from parent
             if kwargs.get('config', None) is None:
                 kwargs['config'] = parent.config
             self.parent = parent
         
         config = kwargs.pop('config', None)
         
         # load kwarg traits, other than config
         super(Configurable, self).__init__(**kwargs)
         
         # load config
         if config is not None:
             # We used to deepcopy, but for now we are trying to just save
             # by reference.  This *could* have side effects as all components
             # will share config. In fact, I did find such a side effect in
             # _config_changed below. If a config attribute value was a mutable type
             # all instances of a component were getting the same copy, effectively
             # making that a class attribute.
             # self.config = deepcopy(config)
             self.config = config
         else:
             # allow _config_default to return something
             self._load_config(self.config)
         
         # Ensure explicit kwargs are applied after loading config.
         # This is usually redundant, but ensures config doesn't override
         # explicitly assigned values.
         for key, value in kwargs.items():
             setattr(self, key, value)
 
     #-------------------------------------------------------------------------
     # Static trait notifiations
     #-------------------------------------------------------------------------
     
     @classmethod
     def section_names(cls):
         """return section names as a list"""
         return  [c.__name__ for c in reversed(cls.__mro__) if
             issubclass(c, Configurable) and issubclass(cls, c)
         ]
     
     def _find_my_config(self, cfg):
         """extract my config from a global Config object
         
         will construct a Config object of only the config values that apply to me
         based on my mro(), as well as those of my parent(s) if they exist.
         
         If I am Bar and my parent is Foo, and their parent is Tim,
         this will return merge following config sections, in this order::
         
             [Bar, Foo.bar, Tim.Foo.Bar]
         
         With the last item being the highest priority.
         """
         cfgs = [cfg]
         if self.parent:
             cfgs.append(self.parent._find_my_config(cfg))
         my_config = Config()
         for c in cfgs:
             for sname in self.section_names():
                 # Don't do a blind getattr as that would cause the config to
                 # dynamically create the section with name Class.__name__.
                 if c._has_section(sname):
                     my_config.merge(c[sname])
         return my_config
     
     def _load_config(self, cfg, section_names=None, traits=None):
         """load traits from a Config object"""
         
         if traits is None:
             traits = self.traits(config=True)
         if section_names is None:
             section_names = self.section_names()
         
         my_config = self._find_my_config(cfg)
         
         # hold trait notifications until after all config has been loaded
         with self.hold_trait_notifications():
             for name, config_value in iteritems(my_config):
                 if name in traits:
                     if isinstance(config_value, LazyConfigValue):
                         # ConfigValue is a wrapper for using append / update on containers
                         # without having to copy the initial value
                         initial = getattr(self, name)
                         config_value = config_value.get_value(initial)
                     # We have to do a deepcopy here if we don't deepcopy the entire
                     # config object. If we don't, a mutable config_value will be
                     # shared by all instances, effectively making it a class attribute.
                     setattr(self, name, deepcopy(config_value))
 
     def _config_changed(self, name, old, new):
         """Update all the class traits having ``config=True`` as metadata.
 
         For any class trait with a ``config`` metadata attribute that is
         ``True``, we update the trait with the value of the corresponding
         config entry.
         """
         # Get all traits with a config metadata entry that is True
         traits = self.traits(config=True)
 
         # We auto-load config section for this class as well as any parent
         # classes that are Configurable subclasses.  This starts with Configurable
         # and works down the mro loading the config for each section.
         section_names = self.section_names()
         self._load_config(new, traits=traits, section_names=section_names)
 
     def update_config(self, config):
         """Fire the traits events when the config is updated."""
         # Save a copy of the current config.
         newconfig = deepcopy(self.config)
         # Merge the new config into the current one.
         newconfig.merge(config)
         # Save the combined config as self.config, which triggers the traits
         # events.
         self.config = newconfig
 
     @classmethod
     def class_get_help(cls, inst=None):
         """Get the help string for this class in ReST format.
         
         If `inst` is given, it's current trait values will be used in place of
         class defaults.
         """
         assert inst is None or isinstance(inst, cls)
         final_help = []
         final_help.append(u'%s options' % cls.__name__)
         final_help.append(len(final_help[0])*u'-')
         for k, v in sorted(cls.class_traits(config=True).items()):
             help = cls.class_get_trait_help(v, inst)
             final_help.append(help)
         return '\n'.join(final_help)
 
     @classmethod
     def class_get_trait_help(cls, trait, inst=None):
         """Get the help string for a single trait.
         
         If `inst` is given, it's current trait values will be used in place of
         the class default.
         """
         assert inst is None or isinstance(inst, cls)
         lines = []
         header = "--%s.%s=<%s>" % (cls.__name__, trait.name, trait.__class__.__name__)
         lines.append(header)
         if inst is not None:
             lines.append(indent('Current: %r' % getattr(inst, trait.name), 4))
         else:
             try:
                 dvr = repr(trait.get_default_value())
             except Exception:
                 dvr = None # ignore defaults we can't construct
             if dvr is not None:
                 if len(dvr) > 64:
                     dvr = dvr[:61]+'...'
                 lines.append(indent('Default: %s' % dvr, 4))
         if 'Enum' in trait.__class__.__name__:
             # include Enum choices
             lines.append(indent('Choices: %r' % (trait.values,)))
 
         help = trait.get_metadata('help')
         if help is not None:
             help = '\n'.join(wrap_paragraphs(help, 76))
             lines.append(indent(help, 4))
         return '\n'.join(lines)
 
     @classmethod
     def class_print_help(cls, inst=None):
         """Get the help string for a single trait and print it."""
         print(cls.class_get_help(inst))
 
     @classmethod
     def class_config_section(cls):
         """Get the config class config section"""
         def c(s):
             """return a commented, wrapped block."""
             s = '\n\n'.join(wrap_paragraphs(s, 78))
 
             return '# ' + s.replace('\n', '\n# ')
 
         # section header
         breaker = '#' + '-'*78
         s = "# %s configuration" % cls.__name__
         lines = [breaker, s, breaker, '']
         # get the description trait
         desc = cls.class_traits().get('description')
         if desc:
             desc = desc.default_value
         else:
             # no description trait, use __doc__
             desc = getattr(cls, '__doc__', '')
         if desc:
             lines.append(c(desc))
             lines.append('')
 
         parents = []
         for parent in cls.mro():
             # only include parents that are not base classes
             # and are not the class itself
             # and have some configurable traits to inherit
             if parent is not cls and issubclass(parent, Configurable) and \
                     parent.class_traits(config=True):
                 parents.append(parent)
 
         if parents:
             pstr = ', '.join([ p.__name__ for p in parents ])
             lines.append(c('%s will inherit config from: %s'%(cls.__name__, pstr)))
             lines.append('')
 
         for name, trait in iteritems(cls.class_traits(config=True)):
             help = trait.get_metadata('help') or ''
             lines.append(c(help))
             lines.append('# c.%s.%s = %r'%(cls.__name__, name, trait.get_default_value()))
             lines.append('')
         return '\n'.join(lines)
 
 
 
 class SingletonConfigurable(Configurable):
     """A configurable that only allows one instance.
 
     This class is for classes that should only have one instance of itself
     or *any* subclass. To create and retrieve such a class use the
     :meth:`SingletonConfigurable.instance` method.
     """
 
     _instance = None
 
     @classmethod
     def _walk_mro(cls):
         """Walk the cls.mro() for parent classes that are also singletons
 
         For use in instance()
         """
 
         for subclass in cls.mro():
             if issubclass(cls, subclass) and \
                     issubclass(subclass, SingletonConfigurable) and \
                     subclass != SingletonConfigurable:
                 yield subclass
 
     @classmethod
     def clear_instance(cls):
         """unset _instance for this class and singleton parents.
         """
         if not cls.initialized():
             return
         for subclass in cls._walk_mro():
             if isinstance(subclass._instance, cls):
                 # only clear instances that are instances
                 # of the calling class
                 subclass._instance = None
 
     @classmethod
     def instance(cls, *args, **kwargs):
         """Returns a global instance of this class.
 
         This method create a new instance if none have previously been created
         and returns a previously created instance is one already exists.
 
         The arguments and keyword arguments passed to this method are passed
         on to the :meth:`__init__` method of the class upon instantiation.
 
         Examples
         --------
 
         Create a singleton class using instance, and retrieve it::
 
             >>> from IPython.config.configurable import SingletonConfigurable
             >>> class Foo(SingletonConfigurable): pass
             >>> foo = Foo.instance()
             >>> foo == Foo.instance()
             True
 
         Create a subclass that is retrived using the base class instance::
 
             >>> class Bar(SingletonConfigurable): pass
             >>> class Bam(Bar): pass
             >>> bam = Bam.instance()
             >>> bam == Bar.instance()
             True
         """
         # Create and save the instance
         if cls._instance is None:
             inst = cls(*args, **kwargs)
             # Now make sure that the instance will also be returned by
             # parent classes' _instance attribute.
             for subclass in cls._walk_mro():
                 subclass._instance = inst
 
         if isinstance(cls._instance, cls):
             return cls._instance
         else:
             raise MultipleInstanceError(
                 'Multiple incompatible subclass instances of '
                 '%s are being created.' % cls.__name__
             )
 
     @classmethod
     def initialized(cls):
         """Has an instance been created?"""
         return hasattr(cls, "_instance") and cls._instance is not None
 
 
 class LoggingConfigurable(Configurable):
     """A parent class for Configurables that log.
 
     Subclasses have a log trait, and the default behavior
     is to get the logger from the currently running Application.
     """
 
-    log = Instance('logging.Logger')
+    log = Instance('logging.Logger', allow_none=True)
     def _log_default(self):
         from IPython.utils import log
         return log.get_logger()
 
 

IPython/core/alias.py

@@ -1,256 +1,256 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 os
 import re
 import sys
 
 from IPython.config.configurable import Configurable
 from IPython.core.error import UsageError
 
 from IPython.utils.py3compat import string_types
 from IPython.utils.traitlets import List, Instance
 from IPython.utils.warn import 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'), ('rm', 'rm'), ('cp', 'cp'),
                            ('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 /$'),
                           # things which are executable
                           ('lx', 'ls -F -o --color %l | grep ^-..x'),
                           ]
         elif sys.platform.startswith('openbsd') or sys.platform.startswith('netbsd'):
             # OpenBSD, NetBSD. The ls implementation on these platforms do not support
             # the -G switch and lack the ability to use colorized output.
             ls_aliases = [('ls', 'ls -F'),
                           # long ls
                           ('ll', 'ls -F -l'),
                           # ls normal files only
                           ('lf', 'ls -F -l %l | grep ^-'),
                           # ls symbolic links
                           ('lk', 'ls -F -l %l | grep ^l'),
                           # directories or links to directories,
                           ('ldir', 'ls -F -l %l | grep /$'),
                           # things which are executable
                           ('lx', 'ls -F -l %l | grep ^-..x'),
                           ]
         else:
             # BSD, OSX, etc.
             ls_aliases = [('ls', 'ls -F -G'),
                           # long ls
                           ('ll', 'ls -F -l -G'),
                           # ls normal files only
                           ('lf', 'ls -F -l -G %l | grep ^-'),
                           # ls symbolic links
                           ('lk', 'ls -F -l -G %l | grep ^l'),
                           # directories or links to directories,
                           ('ldir', 'ls -F -G -l %l | grep /$'),
                           # things which are executable
                           ('lx', 'ls -F -l -G %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
 
 class Alias(object):
     """Callable object storing the details of one alias.
 
     Instances are registered as magic functions to allow use of aliases.
     """
 
     # Prepare blacklist
     blacklist = {'cd','popd','pushd','dhist','alias','unalias'}
 
     def __init__(self, shell, name, cmd):
         self.shell = shell
         self.name = name
         self.cmd = cmd
         self.nargs = self.validate()
 
     def validate(self):
         """Validate the alias, and return the number of arguments."""
         if self.name in self.blacklist:
             raise InvalidAliasError("The name %s can't be aliased "
                                     "because it is a keyword or builtin." % self.name)
         try:
             caller = self.shell.magics_manager.magics['line'][self.name]
         except KeyError:
             pass
         else:
             if not isinstance(caller, Alias):
                 raise InvalidAliasError("The name %s can't be aliased "
                                         "because it is another magic command." % self.name)
 
         if not (isinstance(self.cmd, string_types)):
             raise InvalidAliasError("An alias command must be a string, "
                                     "got: %r" % self.cmd)
 
         nargs = self.cmd.count('%s') - self.cmd.count('%%s')
   
         if (nargs > 0) and (self.cmd.find('%l') >= 0):
             raise InvalidAliasError('The %s and %l specifiers are mutually '
                                     'exclusive in alias definitions.')
 
         return nargs
 
     def __repr__(self):
         return "<alias {} for {!r}>".format(self.name, self.cmd)
 
     def __call__(self, rest=''):
         cmd = self.cmd
         nargs = self.nargs
         # 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:
             if cmd.find('%%s') >= 1:
                 cmd = cmd.replace('%%s', '%s')
             # 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 UsageError('Alias <%s> requires %s arguments, %s given.' %
                       (self.name, nargs, len(args)))
             cmd = '%s %s' % (cmd % tuple(args[:nargs]),' '.join(args[nargs:]))
 
         self.shell.system(cmd)
 
 #-----------------------------------------------------------------------------
 # 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')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
 
     def __init__(self, shell=None, **kwargs):
         super(AliasManager, self).__init__(shell=shell, **kwargs)
         # For convenient access
         self.linemagics = self.shell.magics_manager.magics['line']
         self.init_aliases()
 
     def init_aliases(self):
         # Load default & user aliases
         for name, cmd in self.default_aliases + self.user_aliases:
             self.soft_define_alias(name, cmd)
 
     @property
     def aliases(self):
         return [(n, func.cmd) for (n, func) in self.linemagics.items()
                             if isinstance(func, Alias)]
 
     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 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.
         """
         caller = Alias(shell=self.shell, name=name, cmd=cmd)
         self.shell.magics_manager.register_function(caller, magic_kind='line',
                                                     magic_name=name)
 
     def get_alias(self, name):
         """Return an alias, or None if no alias by that name exists."""
         aname = self.linemagics.get(name, None)
         return aname if isinstance(aname, Alias) else None
 
     def is_alias(self, name):
         """Return whether or not a given name has been defined as an alias"""
         return self.get_alias(name) is not None
 
     def undefine_alias(self, name):
         if self.is_alias(name):
             del self.linemagics[name]
         else:
             raise ValueError('%s is not an alias' % name)
 
     def clear_aliases(self):
         for name, cmd in self.aliases:
             self.undefine_alias(name)
 
     def retrieve_alias(self, name):
         """Retrieve the command to which an alias expands."""
         caller = self.get_alias(name)
         if caller:
             return caller.cmd
         else:
             raise ValueError('%s is not an alias' % name)

IPython/core/application.py

@@ -1,396 +1,396 b''
 # encoding: utf-8
 """
 An application for IPython.
 
 All top-level applications should use the classes in this module for
 handling configuration and creating configurables.
 
 The job of an :class:`Application` is to create the master configuration
 object and then create the configurable objects, passing the config to them.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import atexit
 import glob
 import logging
 import os
 import shutil
 import sys
 
 from IPython.config.application import Application, catch_config_error
 from IPython.config.loader import ConfigFileNotFound, PyFileConfigLoader
 from IPython.core import release, crashhandler
 from IPython.core.profiledir import ProfileDir, ProfileDirError
 from IPython.utils.path import get_ipython_dir, get_ipython_package_dir, ensure_dir_exists
 from IPython.utils import py3compat
 from IPython.utils.traitlets import List, Unicode, Type, Bool, Dict, Set, Instance
 
 if os.name == 'nt':
     programdata = os.environ.get('PROGRAMDATA', None)
     if programdata:
         SYSTEM_CONFIG_DIRS = [os.path.join(programdata, 'ipython')]
     else:  # PROGRAMDATA is not defined by default on XP.
         SYSTEM_CONFIG_DIRS = []
 else:
     SYSTEM_CONFIG_DIRS = [
         "/usr/local/etc/ipython",
         "/etc/ipython",
     ]
 
 
 # aliases and flags
 
 base_aliases = {
     'profile-dir' : 'ProfileDir.location',
     'profile' : 'BaseIPythonApplication.profile',
     'ipython-dir' : 'BaseIPythonApplication.ipython_dir',
     'log-level' : 'Application.log_level',
     'config' : 'BaseIPythonApplication.extra_config_file',
 }
 
 base_flags = dict(
     debug = ({'Application' : {'log_level' : logging.DEBUG}},
             "set log level to logging.DEBUG (maximize logging output)"),
     quiet = ({'Application' : {'log_level' : logging.CRITICAL}},
             "set log level to logging.CRITICAL (minimize logging output)"),
     init = ({'BaseIPythonApplication' : {
                     'copy_config_files' : True,
                     'auto_create' : True}
             }, """Initialize profile with default config files.  This is equivalent
             to running `ipython profile create <profile>` prior to startup.
             """)
 )
 
 class ProfileAwareConfigLoader(PyFileConfigLoader):
     """A Python file config loader that is aware of IPython profiles."""
     def load_subconfig(self, fname, path=None, profile=None):
         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
         return super(ProfileAwareConfigLoader, self).load_subconfig(fname, path=path)
 
 class BaseIPythonApplication(Application):
 
     name = Unicode(u'ipython')
     description = Unicode(u'IPython: an enhanced interactive Python shell.')
     version = Unicode(release.version)
 
     aliases = Dict(base_aliases)
     flags = Dict(base_flags)
     classes = List([ProfileDir])
     
     # enable `load_subconfig('cfg.py', profile='name')`
     python_config_loader_class = ProfileAwareConfigLoader
 
     # Track whether the config_file has changed,
     # because some logic happens only if we aren't using the default.
     config_file_specified = Set()
 
     config_file_name = Unicode()
     def _config_file_name_default(self):
         return self.name.replace('-','_') + u'_config.py'
     def _config_file_name_changed(self, name, old, new):
         if new != old:
             self.config_file_specified.add(new)
 
     # The directory that contains IPython's builtin profiles.
     builtin_profile_dir = Unicode(
         os.path.join(get_ipython_package_dir(), u'config', u'profile', u'default')
     )
     
     config_file_paths = List(Unicode)
     def _config_file_paths_default(self):
         return [py3compat.getcwd()]
 
     extra_config_file = Unicode(config=True,
     help="""Path to an extra config file to load.
     
     If specified, load this config file in addition to any other IPython config.
     """)
     def _extra_config_file_changed(self, name, old, new):
         try:
             self.config_files.remove(old)
         except ValueError:
             pass
         self.config_file_specified.add(new)
         self.config_files.append(new)
 
     profile = Unicode(u'default', config=True,
         help="""The IPython profile to use."""
     )
 
     def _profile_changed(self, name, old, new):
         self.builtin_profile_dir = os.path.join(
                 get_ipython_package_dir(), u'config', u'profile', new
         )
 
     ipython_dir = Unicode(config=True,
         help="""
         The name of the IPython directory. This directory is used for logging
         configuration (through profiles), history storage, etc. The default
         is usually $HOME/.ipython. This option can also be specified through
         the environment variable IPYTHONDIR.
         """
     )
     def _ipython_dir_default(self):
         d = get_ipython_dir()
         self._ipython_dir_changed('ipython_dir', d, d)
         return d
     
     _in_init_profile_dir = False
-    profile_dir = Instance(ProfileDir)
+    profile_dir = Instance(ProfileDir, allow_none=True)
     def _profile_dir_default(self):
         # avoid recursion
         if self._in_init_profile_dir:
             return
         # profile_dir requested early, force initialization
         self.init_profile_dir()
         return self.profile_dir
 
     overwrite = Bool(False, config=True,
         help="""Whether to overwrite existing config files when copying""")
     auto_create = Bool(False, config=True,
         help="""Whether to create profile dir if it doesn't exist""")
 
     config_files = List(Unicode)
     def _config_files_default(self):
         return [self.config_file_name]
 
     copy_config_files = Bool(False, config=True,
         help="""Whether to install the default config files into the profile dir.
         If a new profile is being created, and IPython contains config files for that
         profile, then they will be staged into the new directory.  Otherwise,
         default config files will be automatically generated.
         """)
     
     verbose_crash = Bool(False, config=True,
         help="""Create a massive crash report when IPython encounters what may be an
         internal error.  The default is to append a short message to the
         usual traceback""")
 
     # The class to use as the crash handler.
     crash_handler_class = Type(crashhandler.CrashHandler)
 
     @catch_config_error
     def __init__(self, **kwargs):
         super(BaseIPythonApplication, self).__init__(**kwargs)
         # ensure current working directory exists
         try:
             directory = py3compat.getcwd()
         except:
             # exit if cwd doesn't exist
             self.log.error("Current working directory doesn't exist.")
             self.exit(1)
 
     #-------------------------------------------------------------------------
     # Various stages of Application creation
     #-------------------------------------------------------------------------
 
     def init_crash_handler(self):
         """Create a crash handler, typically setting sys.excepthook to it."""
         self.crash_handler = self.crash_handler_class(self)
         sys.excepthook = self.excepthook
         def unset_crashhandler():
             sys.excepthook = sys.__excepthook__
         atexit.register(unset_crashhandler)
     
     def excepthook(self, etype, evalue, tb):
         """this is sys.excepthook after init_crashhandler
         
         set self.verbose_crash=True to use our full crashhandler, instead of
         a regular traceback with a short message (crash_handler_lite)
         """
         
         if self.verbose_crash:
             return self.crash_handler(etype, evalue, tb)
         else:
             return crashhandler.crash_handler_lite(etype, evalue, tb)
     
     def _ipython_dir_changed(self, name, old, new):
         if old is not None:
             str_old = py3compat.cast_bytes_py2(os.path.abspath(old),
                 sys.getfilesystemencoding()
             )
             if str_old in sys.path:
                 sys.path.remove(str_old)
         str_path = py3compat.cast_bytes_py2(os.path.abspath(new),
             sys.getfilesystemencoding()
         )
         sys.path.append(str_path)
         ensure_dir_exists(new)
         readme = os.path.join(new, 'README')
         readme_src = os.path.join(get_ipython_package_dir(), u'config', u'profile', 'README')
         if not os.path.exists(readme) and os.path.exists(readme_src):
             shutil.copy(readme_src, readme)
         for d in ('extensions', 'nbextensions'):
             path = os.path.join(new, d)
             try:
                 ensure_dir_exists(path)
             except OSError:
                 # this will not be EEXIST
                 self.log.error("couldn't create path %s: %s", path, e)
         self.log.debug("IPYTHONDIR set to: %s" % new)
 
     def load_config_file(self, suppress_errors=True):
         """Load the config file.
 
         By default, errors in loading config are handled, and a warning
         printed on screen. For testing, the suppress_errors option is set
         to False, so errors will make tests fail.
         """
         self.log.debug("Searching path %s for config files", self.config_file_paths)
         base_config = 'ipython_config.py'
         self.log.debug("Attempting to load config file: %s" %
                        base_config)
         try:
             Application.load_config_file(
                 self,
                 base_config,
                 path=self.config_file_paths
             )
         except ConfigFileNotFound:
             # ignore errors loading parent
             self.log.debug("Config file %s not found", base_config)
             pass
         
         for config_file_name in self.config_files:
             if not config_file_name or config_file_name == base_config:
                 continue
             self.log.debug("Attempting to load config file: %s" %
                            self.config_file_name)
             try:
                 Application.load_config_file(
                     self,
                     config_file_name,
                     path=self.config_file_paths
                 )
             except ConfigFileNotFound:
                 # Only warn if the default config file was NOT being used.
                 if config_file_name in self.config_file_specified:
                     msg = self.log.warn
                 else:
                     msg = self.log.debug
                 msg("Config file not found, skipping: %s", config_file_name)
             except:
                 # For testing purposes.
                 if not suppress_errors:
                     raise
                 self.log.warn("Error loading config file: %s" %
                               self.config_file_name, exc_info=True)
 
     def init_profile_dir(self):
         """initialize the profile dir"""
         self._in_init_profile_dir = True
         if self.profile_dir is not None:
             # already ran
             return
         if 'ProfileDir.location' not in self.config:
             # location not specified, find by profile name
             try:
                 p = ProfileDir.find_profile_dir_by_name(self.ipython_dir, self.profile, self.config)
             except ProfileDirError:
                 # not found, maybe create it (always create default profile)
                 if self.auto_create or self.profile == 'default':
                     try:
                         p = ProfileDir.create_profile_dir_by_name(self.ipython_dir, self.profile, self.config)
                     except ProfileDirError:
                         self.log.fatal("Could not create profile: %r"%self.profile)
                         self.exit(1)
                     else:
                         self.log.info("Created profile dir: %r"%p.location)
                 else:
                     self.log.fatal("Profile %r not found."%self.profile)
                     self.exit(1)
             else:
                 self.log.debug("Using existing profile dir: %r"%p.location)
         else:
             location = self.config.ProfileDir.location
             # location is fully specified
             try:
                 p = ProfileDir.find_profile_dir(location, self.config)
             except ProfileDirError:
                 # not found, maybe create it
                 if self.auto_create:
                     try:
                         p = ProfileDir.create_profile_dir(location, self.config)
                     except ProfileDirError:
                         self.log.fatal("Could not create profile directory: %r"%location)
                         self.exit(1)
                     else:
                         self.log.debug("Creating new profile dir: %r"%location)
                 else:
                     self.log.fatal("Profile directory %r not found."%location)
                     self.exit(1)
             else:
                 self.log.info("Using existing profile dir: %r"%location)
             # if profile_dir is specified explicitly, set profile name
             dir_name = os.path.basename(p.location)
             if dir_name.startswith('profile_'):
                 self.profile = dir_name[8:]
 
         self.profile_dir = p
         self.config_file_paths.append(p.location)
         self._in_init_profile_dir = False
 
     def init_config_files(self):
         """[optionally] copy default config files into profile dir."""
         self.config_file_paths.extend(SYSTEM_CONFIG_DIRS)
         # copy config files
         path = self.builtin_profile_dir
         if self.copy_config_files:
             src = self.profile
 
             cfg = self.config_file_name
             if path and os.path.exists(os.path.join(path, cfg)):
                 self.log.warn("Staging %r from %s into %r [overwrite=%s]"%(
                         cfg, src, self.profile_dir.location, self.overwrite)
                 )
                 self.profile_dir.copy_config_file(cfg, path=path, overwrite=self.overwrite)
             else:
                 self.stage_default_config_file()
         else:
             # Still stage *bundled* config files, but not generated ones
             # This is necessary for `ipython profile=sympy` to load the profile
             # on the first go
             files = glob.glob(os.path.join(path, '*.py'))
             for fullpath in files:
                 cfg = os.path.basename(fullpath)
                 if self.profile_dir.copy_config_file(cfg, path=path, overwrite=False):
                     # file was copied
                     self.log.warn("Staging bundled %s from %s into %r"%(
                             cfg, self.profile, self.profile_dir.location)
                     )
 
 
     def stage_default_config_file(self):
         """auto generate default config file, and stage it into the profile."""
         s = self.generate_config_file()
         fname = os.path.join(self.profile_dir.location, self.config_file_name)
         if self.overwrite or not os.path.exists(fname):
             self.log.warn("Generating default config file: %r"%(fname))
             with open(fname, 'w') as f:
                 f.write(s)
 
     @catch_config_error
     def initialize(self, argv=None):
         # don't hook up crash handler before parsing command-line
         self.parse_command_line(argv)
         self.init_crash_handler()
         if self.subapp is not None:
             # stop here if subapp is taking over
             return
         cl_config = self.config
         self.init_profile_dir()
         self.init_config_files()
         self.load_config_file()
         # enforce cl-opts override configfile opts:
         self.update_config(cl_config)
 

IPython/core/builtin_trap.py

@@ -1,111 +1,112 b''
 """
 A context manager for managing things injected into :mod:`__builtin__`.
 
 Authors:
 
 * Brian Granger
 * Fernando Perez
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011  The IPython Development Team.
 #
 #  Distributed under the terms of the BSD License.
 #
 #  Complete license in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from IPython.config.configurable import Configurable
 
 from IPython.utils.py3compat import builtin_mod, iteritems
 from IPython.utils.traitlets import Instance
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 class __BuiltinUndefined(object): pass
 BuiltinUndefined = __BuiltinUndefined()
 
 class __HideBuiltin(object): pass
 HideBuiltin = __HideBuiltin()
 
 
 class BuiltinTrap(Configurable):
 
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
+                     allow_none=True)
 
     def __init__(self, shell=None):
         super(BuiltinTrap, self).__init__(shell=shell, config=None)
         self._orig_builtins = {}
         # We define this to track if a single BuiltinTrap is nested.
         # Only turn off the trap when the outermost call to __exit__ is made.
         self._nested_level = 0
         self.shell = shell
         # builtins we always add - if set to HideBuiltin, they will just
         # be removed instead of being replaced by something else
         self.auto_builtins = {'exit': HideBuiltin,
                               'quit': HideBuiltin,
                               'get_ipython': self.shell.get_ipython,
                               }
         # Recursive reload function
         try:
             from IPython.lib import deepreload
             if self.shell.deep_reload:
                 self.auto_builtins['reload'] = deepreload.reload
             else:
                 self.auto_builtins['dreload']= deepreload.reload
         except ImportError:
             pass
 
     def __enter__(self):
         if self._nested_level == 0:
             self.activate()
         self._nested_level += 1
         # I return self, so callers can use add_builtin in a with clause.
         return self
 
     def __exit__(self, type, value, traceback):
         if self._nested_level == 1:
             self.deactivate()
         self._nested_level -= 1
         # Returning False will cause exceptions to propagate
         return False
 
     def add_builtin(self, key, value):
         """Add a builtin and save the original."""
         bdict = builtin_mod.__dict__
         orig = bdict.get(key, BuiltinUndefined)
         if value is HideBuiltin:
             if orig is not BuiltinUndefined: #same as 'key in bdict'
                 self._orig_builtins[key] = orig
                 del bdict[key]
         else:
             self._orig_builtins[key] = orig
             bdict[key] = value
 
     def remove_builtin(self, key, orig):
         """Remove an added builtin and re-set the original."""
         if orig is BuiltinUndefined:
             del builtin_mod.__dict__[key]
         else:
             builtin_mod.__dict__[key] = orig
 
     def activate(self):
         """Store ipython references in the __builtin__ namespace."""
 
         add_builtin = self.add_builtin
         for name, func in iteritems(self.auto_builtins):
             add_builtin(name, func)
 
     def deactivate(self):
         """Remove any builtins which might have been added by add_builtins, or
         restore overwritten ones to their previous values."""
         remove_builtin = self.remove_builtin
         for key, val in iteritems(self._orig_builtins):
             remove_builtin(key, val)
         self._orig_builtins.clear()
         self._builtins_added = False

IPython/core/displayhook.py

@@ -1,282 +1,283 b''
 # -*- coding: utf-8 -*-
 """Displayhook for IPython.
 
 This defines a callable class that IPython uses for `sys.displayhook`.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import sys
 
 from IPython.core.formatters import _safe_get_formatter_method
 from IPython.config.configurable import Configurable
 from IPython.utils import io
 from IPython.utils.py3compat import builtin_mod
 from IPython.utils.traitlets import Instance, Float
 from IPython.utils.warn import warn
 
 # TODO: Move the various attributes (cache_size, [others now moved]). Some
 # of these are also attributes of InteractiveShell. They should be on ONE object
 # only and the other objects should ask that one object for their values.
 
 class DisplayHook(Configurable):
     """The custom IPython displayhook to replace sys.displayhook.
 
     This class does many things, but the basic idea is that it is a callable
     that gets called anytime user code returns a value.
     """
 
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
+                     allow_none=True)
     exec_result = Instance('IPython.core.interactiveshell.ExecutionResult',
                            allow_none=True)
     cull_fraction = Float(0.2)
 
     def __init__(self, shell=None, cache_size=1000, **kwargs):
         super(DisplayHook, self).__init__(shell=shell, **kwargs)
         cache_size_min = 3
         if cache_size <= 0:
             self.do_full_cache = 0
             cache_size = 0
         elif cache_size < cache_size_min:
             self.do_full_cache = 0
             cache_size = 0
             warn('caching was disabled (min value for cache size is %s).' %
                  cache_size_min,level=3)
         else:
             self.do_full_cache = 1
 
         self.cache_size = cache_size
 
         # we need a reference to the user-level namespace
         self.shell = shell
         
         self._,self.__,self.___ = '','',''
 
         # these are deliberately global:
         to_user_ns = {'_':self._,'__':self.__,'___':self.___}
         self.shell.user_ns.update(to_user_ns)
 
     @property
     def prompt_count(self):
         return self.shell.execution_count
 
     #-------------------------------------------------------------------------
     # Methods used in __call__. Override these methods to modify the behavior
     # of the displayhook.
     #-------------------------------------------------------------------------
 
     def check_for_underscore(self):
         """Check if the user has set the '_' variable by hand."""
         # If something injected a '_' variable in __builtin__, delete
         # ipython's automatic one so we don't clobber that.  gettext() in
         # particular uses _, so we need to stay away from it.
         if '_' in builtin_mod.__dict__:
             try:
                 del self.shell.user_ns['_']
             except KeyError:
                 pass
 
     def quiet(self):
         """Should we silence the display hook because of ';'?"""
         # do not print output if input ends in ';'
         try:
             cell = self.shell.history_manager.input_hist_parsed[self.prompt_count]
             return cell.rstrip().endswith(';')
         except IndexError:
             # some uses of ipshellembed may fail here
             return False
 
     def start_displayhook(self):
         """Start the displayhook, initializing resources."""
         pass
 
     def write_output_prompt(self):
         """Write the output prompt.
 
         The default implementation simply writes the prompt to
         ``io.stdout``.
         """
         # Use write, not print which adds an extra space.
         io.stdout.write(self.shell.separate_out)
         outprompt = self.shell.prompt_manager.render('out')
         if self.do_full_cache:
             io.stdout.write(outprompt)
 
     def compute_format_data(self, result):
         """Compute format data of the object to be displayed.
 
         The format data is a generalization of the :func:`repr` of an object.
         In the default implementation the format data is a :class:`dict` of
         key value pair where the keys are valid MIME types and the values
         are JSON'able data structure containing the raw data for that MIME
         type. It is up to frontends to determine pick a MIME to to use and
         display that data in an appropriate manner.
 
         This method only computes the format data for the object and should
         NOT actually print or write that to a stream.
 
         Parameters
         ----------
         result : object
             The Python object passed to the display hook, whose format will be
             computed.
 
         Returns
         -------
         (format_dict, md_dict) : dict
             format_dict is a :class:`dict` whose keys are valid MIME types and values are
             JSON'able raw data for that MIME type. It is recommended that
             all return values of this should always include the "text/plain"
             MIME type representation of the object.
             md_dict is a :class:`dict` with the same MIME type keys
             of metadata associated with each output.
             
         """
         return self.shell.display_formatter.format(result)
 
     def write_format_data(self, format_dict, md_dict=None):
         """Write the format data dict to the frontend.
 
         This default version of this method simply writes the plain text
         representation of the object to ``io.stdout``. Subclasses should
         override this method to send the entire `format_dict` to the
         frontends.
 
         Parameters
         ----------
         format_dict : dict
             The format dict for the object passed to `sys.displayhook`.
         md_dict : dict (optional)
             The metadata dict to be associated with the display data.
         """
         if 'text/plain' not in format_dict:
             # nothing to do
             return
         # We want to print because we want to always make sure we have a
         # newline, even if all the prompt separators are ''. This is the
         # standard IPython behavior.
         result_repr = format_dict['text/plain']
         if '\n' in result_repr:
             # So that multi-line strings line up with the left column of
             # the screen, instead of having the output prompt mess up
             # their first line.
             # We use the prompt template instead of the expanded prompt
             # because the expansion may add ANSI escapes that will interfere
             # with our ability to determine whether or not we should add
             # a newline.
             prompt_template = self.shell.prompt_manager.out_template
             if prompt_template and not prompt_template.endswith('\n'):
                 # But avoid extraneous empty lines.
                 result_repr = '\n' + result_repr
 
         print(result_repr, file=io.stdout)
 
     def update_user_ns(self, result):
         """Update user_ns with various things like _, __, _1, etc."""
 
         # Avoid recursive reference when displaying _oh/Out
         if result is not self.shell.user_ns['_oh']:
             if len(self.shell.user_ns['_oh']) >= self.cache_size and self.do_full_cache:
                 self.cull_cache()
             # Don't overwrite '_' and friends if '_' is in __builtin__ (otherwise
             # we cause buggy behavior for things like gettext).
 
             if '_' not in builtin_mod.__dict__:
                 self.___ = self.__
                 self.__ = self._
                 self._ = result
                 self.shell.push({'_':self._,
                                  '__':self.__,
                                 '___':self.___}, interactive=False)
 
             # hackish access to top-level  namespace to create _1,_2... dynamically
             to_main = {}
             if self.do_full_cache:
                 new_result = '_'+repr(self.prompt_count)
                 to_main[new_result] = result
                 self.shell.push(to_main, interactive=False)
                 self.shell.user_ns['_oh'][self.prompt_count] = result
 
     def fill_exec_result(self, result):
         if self.exec_result is not None:
             self.exec_result.result = result
 
     def log_output(self, format_dict):
         """Log the output."""
         if 'text/plain' not in format_dict:
             # nothing to do
             return
         if self.shell.logger.log_output:
             self.shell.logger.log_write(format_dict['text/plain'], 'output')
         self.shell.history_manager.output_hist_reprs[self.prompt_count] = \
                                                     format_dict['text/plain']
 
     def finish_displayhook(self):
         """Finish up all displayhook activities."""
         io.stdout.write(self.shell.separate_out2)
         io.stdout.flush()
 
     def __call__(self, result=None):
         """Printing with history cache management.
 
         This is invoked everytime the interpreter needs to print, and is
         activated by setting the variable sys.displayhook to it.
         """
         self.check_for_underscore()
         if result is not None and not self.quiet():
             self.start_displayhook()
             self.write_output_prompt()
             format_dict, md_dict = self.compute_format_data(result)
             self.update_user_ns(result)
             self.fill_exec_result(result)
             if format_dict:
                 self.write_format_data(format_dict, md_dict)
                 self.log_output(format_dict)
             self.finish_displayhook()
 
     def cull_cache(self):
         """Output cache is full, cull the oldest entries"""
         oh = self.shell.user_ns.get('_oh', {})
         sz = len(oh)
         cull_count = max(int(sz * self.cull_fraction), 2)
         warn('Output cache limit (currently {sz} entries) hit.\n'
              'Flushing oldest {cull_count} entries.'.format(sz=sz, cull_count=cull_count))
         
         for i, n in enumerate(sorted(oh)):
             if i >= cull_count:
                 break
             self.shell.user_ns.pop('_%i' % n, None)
             oh.pop(n, None)
         
 
     def flush(self):
         if not self.do_full_cache:
             raise ValueError("You shouldn't have reached the cache flush "
                              "if full caching is not enabled!")
         # delete auto-generated vars from global namespace
 
         for n in range(1,self.prompt_count + 1):
             key = '_'+repr(n)
             try:
                 del self.shell.user_ns[key]
             except: pass
         # In some embedded circumstances, the user_ns doesn't have the
         # '_oh' key set up.
         oh = self.shell.user_ns.get('_oh', None)
         if oh is not None:
             oh.clear()
 
         # Release our own references to objects:
         self._, self.__, self.___ = '', '', ''
 
         if '_' not in builtin_mod.__dict__:
             self.shell.user_ns.update({'_':None,'__':None, '___':None})
         import gc
         # TODO: Is this really needed?
         # IronPython blocks here forever
         if sys.platform != "cli":
             gc.collect()
 

IPython/core/extensions.py

@@ -1,175 +1,176 b''
 # encoding: utf-8
 """A class for managing IPython extensions."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 from shutil import copyfile
 import sys
 
 from IPython.config.configurable import Configurable
 from IPython.utils.path import ensure_dir_exists
 from IPython.utils.traitlets import Instance
 from IPython.utils.py3compat import PY3
 if PY3:
     from imp import reload
 
 #-----------------------------------------------------------------------------
 # Main class
 #-----------------------------------------------------------------------------
 
 class ExtensionManager(Configurable):
     """A class to manage IPython extensions.
 
     An IPython extension is an importable Python module that has
     a function with the signature::
 
         def load_ipython_extension(ipython):
             # Do things with ipython
 
     This function is called after your extension is imported and the
     currently active :class:`InteractiveShell` instance is passed as
     the only argument.  You can do anything you want with IPython at
     that point, including defining new magic and aliases, adding new
     components, etc.
     
     You can also optionally define an :func:`unload_ipython_extension(ipython)`
     function, which will be called if the user unloads or reloads the extension.
     The extension manager will only call :func:`load_ipython_extension` again
     if the extension is reloaded.
 
     You can put your extension modules anywhere you want, as long as
     they can be imported by Python's standard import mechanism.  However,
     to make it easy to write extensions, you can also put your extensions
     in ``os.path.join(self.ipython_dir, 'extensions')``.  This directory
     is added to ``sys.path`` automatically.
     """
 
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
+                     allow_none=True)
 
     def __init__(self, shell=None, **kwargs):
         super(ExtensionManager, self).__init__(shell=shell, **kwargs)
         self.shell.on_trait_change(
             self._on_ipython_dir_changed, 'ipython_dir'
         )
         self.loaded = set()
 
     def __del__(self):
         self.shell.on_trait_change(
             self._on_ipython_dir_changed, 'ipython_dir', remove=True
         )
 
     @property
     def ipython_extension_dir(self):
         return os.path.join(self.shell.ipython_dir, u'extensions')
 
     def _on_ipython_dir_changed(self):
         ensure_dir_exists(self.ipython_extension_dir)
 
     def load_extension(self, module_str):
         """Load an IPython extension by its module name.
 
         Returns the string "already loaded" if the extension is already loaded,
         "no load function" if the module doesn't have a load_ipython_extension
         function, or None if it succeeded.
         """
         if module_str in self.loaded:
             return "already loaded"
         
         from IPython.utils.syspathcontext import prepended_to_syspath
         
         with self.shell.builtin_trap:
             if module_str not in sys.modules:
                 with prepended_to_syspath(self.ipython_extension_dir):
                     __import__(module_str)
             mod = sys.modules[module_str]
             if self._call_load_ipython_extension(mod):
                 self.loaded.add(module_str)
             else:
                 return "no load function"
 
     def unload_extension(self, module_str):
         """Unload an IPython extension by its module name.
 
         This function looks up the extension's name in ``sys.modules`` and
         simply calls ``mod.unload_ipython_extension(self)``.
         
         Returns the string "no unload function" if the extension doesn't define
         a function to unload itself, "not loaded" if the extension isn't loaded,
         otherwise None.
         """
         if module_str not in self.loaded:
             return "not loaded"
         
         if module_str in sys.modules:
             mod = sys.modules[module_str]
             if self._call_unload_ipython_extension(mod):
                 self.loaded.discard(module_str)
             else:
                 return "no unload function"
 
     def reload_extension(self, module_str):
         """Reload an IPython extension by calling reload.
 
         If the module has not been loaded before,
         :meth:`InteractiveShell.load_extension` is called. Otherwise
         :func:`reload` is called and then the :func:`load_ipython_extension`
         function of the module, if it exists is called.
         """
         from IPython.utils.syspathcontext import prepended_to_syspath
 
         if (module_str in self.loaded) and (module_str in sys.modules):
             self.unload_extension(module_str)
             mod = sys.modules[module_str]
             with prepended_to_syspath(self.ipython_extension_dir):
                 reload(mod)
             if self._call_load_ipython_extension(mod):
                 self.loaded.add(module_str)
         else:
             self.load_extension(module_str)
 
     def _call_load_ipython_extension(self, mod):
         if hasattr(mod, 'load_ipython_extension'):
             mod.load_ipython_extension(self.shell)
             return True
 
     def _call_unload_ipython_extension(self, mod):
         if hasattr(mod, 'unload_ipython_extension'):
             mod.unload_ipython_extension(self.shell)
             return True
 
     def install_extension(self, url, filename=None):
         """Download and install an IPython extension. 
 
         If filename is given, the file will be so named (inside the extension
         directory). Otherwise, the name from the URL will be used. The file must
         have a .py or .zip extension; otherwise, a ValueError will be raised.
 
         Returns the full path to the installed file.
         """
         # Ensure the extension directory exists
         ensure_dir_exists(self.ipython_extension_dir)
 
         if os.path.isfile(url):
             src_filename = os.path.basename(url)
             copy = copyfile
         else:
             # Deferred imports
             try:
                 from urllib.parse import urlparse  # Py3
                 from urllib.request import urlretrieve
             except ImportError:
                 from urlparse import urlparse
                 from urllib import urlretrieve
             src_filename = urlparse(url).path.split('/')[-1]
             copy = urlretrieve
 
         if filename is None:
             filename = src_filename
         if os.path.splitext(filename)[1] not in ('.py', '.zip'):
             raise ValueError("The file must have a .py or .zip extension", filename)
 
         filename = os.path.join(self.ipython_extension_dir, filename)
         copy(url, filename)
         return filename

IPython/core/history.py

@@ -1,870 +1,872 b''
 """ History related magics and functionality """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011 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
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib imports
 import atexit
 import datetime
 import os
 import re
 try:
     import sqlite3
 except ImportError:
     try:
         from pysqlite2 import dbapi2 as sqlite3
     except ImportError:
         sqlite3 = None
 import threading
 
 # Our own packages
 from IPython.config.configurable import Configurable
 from decorator import decorator
 from IPython.utils.decorators import undoc
 from IPython.utils.path import locate_profile
 from IPython.utils import py3compat
 from IPython.utils.traitlets import (
     Any, Bool, Dict, Instance, Integer, List, Unicode, TraitError,
 )
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 @undoc
 class DummyDB(object):
     """Dummy DB that will act as a black hole for history.
     
     Only used in the absence of sqlite"""
     def execute(*args, **kwargs):
         return []
     
     def commit(self, *args, **kwargs):
         pass
     
     def __enter__(self, *args, **kwargs):
         pass
     
     def __exit__(self, *args, **kwargs):
         pass
 
 
 @decorator
 def needs_sqlite(f, self, *a, **kw):
     """Decorator: return an empty list in the absence of sqlite."""
     if sqlite3 is None or not self.enabled:
         return []
     else:
         return f(self, *a, **kw)
 
 
 if sqlite3 is not None:
     DatabaseError = sqlite3.DatabaseError
 else:
     @undoc
     class DatabaseError(Exception):
         "Dummy exception when sqlite could not be imported. Should never occur."
 
 @decorator
 def catch_corrupt_db(f, self, *a, **kw):
     """A decorator which wraps HistoryAccessor method calls to catch errors from
     a corrupt SQLite database, move the old database out of the way, and create
     a new one.
     """
     try:
         return f(self, *a, **kw)
     except DatabaseError:
         if os.path.isfile(self.hist_file):
             # Try to move the file out of the way
             base,ext = os.path.splitext(self.hist_file)
             newpath = base + '-corrupt' + ext
             os.rename(self.hist_file, newpath)
             self.init_db()
             print("ERROR! History file wasn't a valid SQLite database.",
             "It was moved to %s" % newpath, "and a new file created.")
             return []
         
         else:
             # The hist_file is probably :memory: or something else.
             raise
         
 class HistoryAccessorBase(Configurable):
     """An abstract class for History Accessors """
 
     def get_tail(self, n=10, raw=True, output=False, include_latest=False):
         raise NotImplementedError
 
     def search(self, pattern="*", raw=True, search_raw=True,
                output=False, n=None, unique=False):
         raise NotImplementedError
 
     def get_range(self, session, start=1, stop=None, raw=True,output=False):
         raise NotImplementedError
 
     def get_range_by_str(self, rangestr, raw=True, output=False):
         raise NotImplementedError
 
 
 class HistoryAccessor(HistoryAccessorBase):
     """Access the history database without adding to it.
     
     This is intended for use by standalone history tools. IPython shells use
     HistoryManager, below, which is a subclass of this."""
 
     # String holding the path to the history file
     hist_file = Unicode(config=True,
         help="""Path to file to use for SQLite history database.
         
         By default, IPython will put the history database in the IPython
         profile directory.  If you would rather share one history among
         profiles, you can set this value in each, so that they are consistent.
         
         Due to an issue with fcntl, SQLite is known to misbehave on some NFS
         mounts.  If you see IPython hanging, try setting this to something on a
         local disk, e.g::
         
             ipython --HistoryManager.hist_file=/tmp/ipython_hist.sqlite
         
         """)
     
     enabled = Bool(True, config=True,
         help="""enable the SQLite history
         
         set enabled=False to disable the SQLite history,
         in which case there will be no stored history, no SQLite connection,
         and no background saving thread.  This may be necessary in some
         threaded environments where IPython is embedded.
         """
     )
     
     connection_options = Dict(config=True,
         help="""Options for configuring the SQLite connection
         
         These options are passed as keyword args to sqlite3.connect
         when establishing database conenctions.
         """
     )
 
     # The SQLite database
     db = Any()
     def _db_changed(self, name, old, new):
         """validate the db, since it can be an Instance of two different types"""
         connection_types = (DummyDB,)
         if sqlite3 is not None:
             connection_types = (DummyDB, sqlite3.Connection)
         if not isinstance(new, connection_types):
             msg = "%s.db must be sqlite3 Connection or DummyDB, not %r" % \
                     (self.__class__.__name__, new)
             raise TraitError(msg)
     
     def __init__(self, profile='default', hist_file=u'', **traits):
         """Create a new history accessor.
         
         Parameters
         ----------
         profile : str
           The name of the profile from which to open history.
         hist_file : str
           Path to an SQLite history database stored by IPython. If specified,
           hist_file overrides profile.
         config : :class:`~IPython.config.loader.Config`
           Config object. hist_file can also be set through this.
         """
         # We need a pointer back to the shell for various tasks.
         super(HistoryAccessor, self).__init__(**traits)
         # defer setting hist_file from kwarg until after init,
         # otherwise the default kwarg value would clobber any value
         # set by config
         if hist_file:
             self.hist_file = hist_file
         
         if self.hist_file == u'':
             # No one has set the hist_file, yet.
             self.hist_file = self._get_hist_file_name(profile)
 
         if sqlite3 is None and self.enabled:
             warn("IPython History requires SQLite, your history will not be saved")
             self.enabled = False
         
         self.init_db()
     
     def _get_hist_file_name(self, profile='default'):
         """Find the history file for the given profile name.
         
         This is overridden by the HistoryManager subclass, to use the shell's
         active profile.
         
         Parameters
         ----------
         profile : str
           The name of a profile which has a history file.
         """
         return os.path.join(locate_profile(profile), 'history.sqlite')
     
     @catch_corrupt_db
     def init_db(self):
         """Connect to the database, and create tables if necessary."""
         if not self.enabled:
             self.db = DummyDB()
             return
         
         # use detect_types so that timestamps return datetime objects
         kwargs = dict(detect_types=sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES)
         kwargs.update(self.connection_options)
         self.db = sqlite3.connect(self.hist_file, **kwargs)
         self.db.execute("""CREATE TABLE IF NOT EXISTS sessions (session integer
                         primary key autoincrement, start timestamp,
                         end timestamp, num_cmds integer, remark text)""")
         self.db.execute("""CREATE TABLE IF NOT EXISTS history
                 (session integer, line integer, source text, source_raw text,
                 PRIMARY KEY (session, line))""")
         # Output history is optional, but ensure the table's there so it can be
         # enabled later.
         self.db.execute("""CREATE TABLE IF NOT EXISTS output_history
                         (session integer, line integer, output text,
                         PRIMARY KEY (session, line))""")
         self.db.commit()
 
     def writeout_cache(self):
         """Overridden by HistoryManager to dump the cache before certain
         database lookups."""
         pass
 
     ## -------------------------------
     ## Methods for retrieving history:
     ## -------------------------------
     def _run_sql(self, sql, params, raw=True, output=False):
         """Prepares and runs an SQL query for the history database.
 
         Parameters
         ----------
         sql : str
           Any filtering expressions to go after SELECT ... FROM ...
         params : tuple
           Parameters passed to the SQL query (to replace "?")
         raw, output : bool
           See :meth:`get_range`
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         toget = 'source_raw' if raw else 'source'
         sqlfrom = "history"
         if output:
             sqlfrom = "history LEFT JOIN output_history USING (session, line)"
             toget = "history.%s, output_history.output" % toget
         cur = self.db.execute("SELECT session, line, %s FROM %s " %\
                                 (toget, sqlfrom) + sql, params)
         if output:    # Regroup into 3-tuples, and parse JSON
             return ((ses, lin, (inp, out)) for ses, lin, inp, out in cur)
         return cur
 
     @needs_sqlite
     @catch_corrupt_db
     def get_session_info(self, session):
         """Get info about a session.
 
         Parameters
         ----------
 
         session : int
             Session number to retrieve.
 
         Returns
         -------
         
         session_id : int
            Session ID number
         start : datetime
            Timestamp for the start of the session.
         end : datetime
            Timestamp for the end of the session, or None if IPython crashed.
         num_cmds : int
            Number of commands run, or None if IPython crashed.
         remark : unicode
            A manually set description.
         """
         query = "SELECT * from sessions where session == ?"
         return self.db.execute(query, (session,)).fetchone()
 
     @catch_corrupt_db
     def get_last_session_id(self):
         """Get the last session ID currently in the database.
         
         Within IPython, this should be the same as the value stored in
         :attr:`HistoryManager.session_number`.
         """
         for record in self.get_tail(n=1, include_latest=True):
             return record[0]
 
     @catch_corrupt_db
     def get_tail(self, n=10, raw=True, output=False, include_latest=False):
         """Get the last n lines from the history database.
 
         Parameters
         ----------
         n : int
           The number of lines to get
         raw, output : bool
           See :meth:`get_range`
         include_latest : bool
           If False (default), n+1 lines are fetched, and the latest one
           is discarded. This is intended to be used where the function
           is called by a user command, which it should not return.
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         self.writeout_cache()
         if not include_latest:
             n += 1
         cur = self._run_sql("ORDER BY session DESC, line DESC LIMIT ?",
                                 (n,), raw=raw, output=output)
         if not include_latest:
             return reversed(list(cur)[1:])
         return reversed(list(cur))
 
     @catch_corrupt_db
     def search(self, pattern="*", raw=True, search_raw=True,
                output=False, n=None, unique=False):
         """Search the database using unix glob-style matching (wildcards
         * and ?).
 
         Parameters
         ----------
         pattern : str
           The wildcarded pattern to match when searching
         search_raw : bool
           If True, search the raw input, otherwise, the parsed input
         raw, output : bool
           See :meth:`get_range`
         n : None or int
           If an integer is given, it defines the limit of
           returned entries.
         unique : bool
           When it is true, return only unique entries.
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         tosearch = "source_raw" if search_raw else "source"
         if output:
             tosearch = "history." + tosearch
         self.writeout_cache()
         sqlform = "WHERE %s GLOB ?" % tosearch
         params = (pattern,)
         if unique:
             sqlform += ' GROUP BY {0}'.format(tosearch)
         if n is not None:
             sqlform += " ORDER BY session DESC, line DESC LIMIT ?"
             params += (n,)
         elif unique:
             sqlform += " ORDER BY session, line"
         cur = self._run_sql(sqlform, params, raw=raw, output=output)
         if n is not None:
             return reversed(list(cur))
         return cur
     
     @catch_corrupt_db
     def get_range(self, session, start=1, stop=None, raw=True,output=False):
         """Retrieve input by session.
 
         Parameters
         ----------
         session : int
             Session number to retrieve.
         start : int
             First line to retrieve.
         stop : int
             End of line range (excluded from output itself). If None, retrieve
             to the end of the session.
         raw : bool
             If True, return untranslated input
         output : bool
             If True, attempt to include output. This will be 'real' Python
             objects for the current session, or text reprs from previous
             sessions if db_log_output was enabled at the time. Where no output
             is found, None is used.
 
         Returns
         -------
         entries
           An iterator over the desired lines. Each line is a 3-tuple, either
           (session, line, input) if output is False, or
           (session, line, (input, output)) if output is True.
         """
         if stop:
             lineclause = "line >= ? AND line < ?"
             params = (session, start, stop)
         else:
             lineclause = "line>=?"
             params = (session, start)
 
         return self._run_sql("WHERE session==? AND %s" % lineclause,
                                     params, raw=raw, output=output)
 
     def get_range_by_str(self, rangestr, raw=True, output=False):
         """Get lines of history from a string of ranges, as used by magic
         commands %hist, %save, %macro, etc.
 
         Parameters
         ----------
         rangestr : str
           A string specifying ranges, e.g. "5 ~2/1-4". See
           :func:`magic_history` for full details.
         raw, output : bool
           As :meth:`get_range`
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         for sess, s, e in extract_hist_ranges(rangestr):
             for line in self.get_range(sess, s, e, raw=raw, output=output):
                 yield line
 
 
 class HistoryManager(HistoryAccessor):
     """A class to organize all history-related functionality in one place.
     """
     # Public interface
 
     # An instance of the IPython shell we are attached to
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
+                     allow_none=True)
     # Lists to hold processed and raw history. These start with a blank entry
     # so that we can index them starting from 1
     input_hist_parsed = List([""])
     input_hist_raw = List([""])
     # A list of directories visited during session
     dir_hist = List()
     def _dir_hist_default(self):
         try:
             return [py3compat.getcwd()]
         except OSError:
             return []
 
     # A dict of output history, keyed with ints from the shell's
     # execution count.
     output_hist = Dict()
     # The text/plain repr of outputs.
     output_hist_reprs = Dict()
 
     # The number of the current session in the history database
     session_number = Integer()
     
     db_log_output = Bool(False, config=True,
         help="Should the history database include output? (default: no)"
     )
     db_cache_size = Integer(0, config=True,
         help="Write to database every x commands (higher values save disk access & power).\n"
         "Values of 1 or less effectively disable caching."
     )
     # The input and output caches
     db_input_cache = List()
     db_output_cache = List()
     
     # History saving in separate thread
-    save_thread = Instance('IPython.core.history.HistorySavingThread')
+    save_thread = Instance('IPython.core.history.HistorySavingThread',
+                           allow_none=True)
     try:               # Event is a function returning an instance of _Event...
-        save_flag = Instance(threading._Event)
+        save_flag = Instance(threading._Event, allow_none=True)
     except AttributeError:         # ...until Python 3.3, when it's a class.
-        save_flag = Instance(threading.Event)
+        save_flag = Instance(threading.Event, allow_none=True)
     
     # Private interface
     # Variables used to store the three last inputs from the user.  On each new
     # history update, we populate the user's namespace with these, shifted as
     # necessary.
     _i00 = Unicode(u'')
     _i = Unicode(u'')
     _ii = Unicode(u'')
     _iii = Unicode(u'')
 
     # A regex matching all forms of the exit command, so that we don't store
     # them in the history (it's annoying to rewind the first entry and land on
     # an exit call).
     _exit_re = re.compile(r"(exit|quit)(\s*\(.*\))?$")
 
     def __init__(self, shell=None, config=None, **traits):
         """Create a new history manager associated with a shell instance.
         """
         # We need a pointer back to the shell for various tasks.
         super(HistoryManager, self).__init__(shell=shell, config=config,
             **traits)
         self.save_flag = threading.Event()
         self.db_input_cache_lock = threading.Lock()
         self.db_output_cache_lock = threading.Lock()
         if self.enabled and self.hist_file != ':memory:':
             self.save_thread = HistorySavingThread(self)
             self.save_thread.start()
 
         self.new_session()
 
     def _get_hist_file_name(self, profile=None):
         """Get default history file name based on the Shell's profile.
         
         The profile parameter is ignored, but must exist for compatibility with
         the parent class."""
         profile_dir = self.shell.profile_dir.location
         return os.path.join(profile_dir, 'history.sqlite')
     
     @needs_sqlite
     def new_session(self, conn=None):
         """Get a new session number."""
         if conn is None:
             conn = self.db
         
         with conn:
             cur = conn.execute("""INSERT INTO sessions VALUES (NULL, ?, NULL,
                             NULL, "") """, (datetime.datetime.now(),))
             self.session_number = cur.lastrowid
             
     def end_session(self):
         """Close the database session, filling in the end time and line count."""
         self.writeout_cache()
         with self.db:
             self.db.execute("""UPDATE sessions SET end=?, num_cmds=? WHERE
                             session==?""", (datetime.datetime.now(),
                             len(self.input_hist_parsed)-1, self.session_number))
         self.session_number = 0
                             
     def name_session(self, name):
         """Give the current session a name in the history database."""
         with self.db:
             self.db.execute("UPDATE sessions SET remark=? WHERE session==?",
                             (name, self.session_number))
                             
     def reset(self, new_session=True):
         """Clear the session history, releasing all object references, and
         optionally open a new session."""
         self.output_hist.clear()
         # The directory history can't be completely empty
         self.dir_hist[:] = [py3compat.getcwd()]
         
         if new_session:
             if self.session_number:
                 self.end_session()
             self.input_hist_parsed[:] = [""]
             self.input_hist_raw[:] = [""]
             self.new_session()
 
     # ------------------------------
     # Methods for retrieving history
     # ------------------------------
     def get_session_info(self, session=0):
         """Get info about a session.
 
         Parameters
         ----------
 
         session : int
             Session number to retrieve. The current session is 0, and negative
             numbers count back from current session, so -1 is the previous session.
 
         Returns
         -------
         
         session_id : int
            Session ID number
         start : datetime
            Timestamp for the start of the session.
         end : datetime
            Timestamp for the end of the session, or None if IPython crashed.
         num_cmds : int
            Number of commands run, or None if IPython crashed.
         remark : unicode
            A manually set description.
         """
         if session <= 0:
             session += self.session_number
 
         return super(HistoryManager, self).get_session_info(session=session)
 
     def _get_range_session(self, start=1, stop=None, raw=True, output=False):
         """Get input and output history from the current session. Called by
         get_range, and takes similar parameters."""
         input_hist = self.input_hist_raw if raw else self.input_hist_parsed
             
         n = len(input_hist)
         if start < 0:
             start += n
         if not stop or (stop > n):
             stop = n
         elif stop < 0:
             stop += n
         
         for i in range(start, stop):
             if output:
                 line = (input_hist[i], self.output_hist_reprs.get(i))
             else:
                 line = input_hist[i]
             yield (0, i, line)
     
     def get_range(self, session=0, start=1, stop=None, raw=True,output=False):
         """Retrieve input by session.
         
         Parameters
         ----------
         session : int
             Session number to retrieve. The current session is 0, and negative
             numbers count back from current session, so -1 is previous session.
         start : int
             First line to retrieve.
         stop : int
             End of line range (excluded from output itself). If None, retrieve
             to the end of the session.
         raw : bool
             If True, return untranslated input
         output : bool
             If True, attempt to include output. This will be 'real' Python
             objects for the current session, or text reprs from previous
             sessions if db_log_output was enabled at the time. Where no output
             is found, None is used.
             
         Returns
         -------
         entries
           An iterator over the desired lines. Each line is a 3-tuple, either
           (session, line, input) if output is False, or
           (session, line, (input, output)) if output is True.
         """
         if session <= 0:
             session += self.session_number
         if session==self.session_number:          # Current session
             return self._get_range_session(start, stop, raw, output)
         return super(HistoryManager, self).get_range(session, start, stop, raw,
                                                      output)
 
     ## ----------------------------
     ## Methods for storing history:
     ## ----------------------------
     def store_inputs(self, line_num, source, source_raw=None):
         """Store source and raw input in history and create input cache
         variables ``_i*``.
 
         Parameters
         ----------
         line_num : int
           The prompt number of this input.
 
         source : str
           Python input.
 
         source_raw : str, optional
           If given, this is the raw input without any IPython transformations
           applied to it.  If not given, ``source`` is used.
         """
         if source_raw is None:
             source_raw = source
         source = source.rstrip('\n')
         source_raw = source_raw.rstrip('\n')
 
         # do not store exit/quit commands
         if self._exit_re.match(source_raw.strip()):
             return
 
         self.input_hist_parsed.append(source)
         self.input_hist_raw.append(source_raw)
 
         with self.db_input_cache_lock:
             self.db_input_cache.append((line_num, source, source_raw))
             # Trigger to flush cache and write to DB.
             if len(self.db_input_cache) >= self.db_cache_size:
                 self.save_flag.set()
 
         # update the auto _i variables
         self._iii = self._ii
         self._ii = self._i
         self._i = self._i00
         self._i00 = source_raw
 
         # hackish access to user namespace to create _i1,_i2... dynamically
         new_i = '_i%s' % line_num
         to_main = {'_i': self._i,
                    '_ii': self._ii,
                    '_iii': self._iii,
                    new_i : self._i00 }
         
         if self.shell is not None:
             self.shell.push(to_main, interactive=False)
 
     def store_output(self, line_num):
         """If database output logging is enabled, this saves all the
         outputs from the indicated prompt number to the database. It's
         called by run_cell after code has been executed.
 
         Parameters
         ----------
         line_num : int
           The line number from which to save outputs
         """
         if (not self.db_log_output) or (line_num not in self.output_hist_reprs):
             return
         output = self.output_hist_reprs[line_num]
 
         with self.db_output_cache_lock:
             self.db_output_cache.append((line_num, output))
         if self.db_cache_size <= 1:
             self.save_flag.set()
 
     def _writeout_input_cache(self, conn):
         with conn:
             for line in self.db_input_cache:
                 conn.execute("INSERT INTO history VALUES (?, ?, ?, ?)",
                                 (self.session_number,)+line)
 
     def _writeout_output_cache(self, conn):
         with conn:
             for line in self.db_output_cache:
                 conn.execute("INSERT INTO output_history VALUES (?, ?, ?)",
                                 (self.session_number,)+line)
 
     @needs_sqlite
     def writeout_cache(self, conn=None):
         """Write any entries in the cache to the database."""
         if conn is None:
             conn = self.db
 
         with self.db_input_cache_lock:
             try:
                 self._writeout_input_cache(conn)
             except sqlite3.IntegrityError:
                 self.new_session(conn)
                 print("ERROR! Session/line number was not unique in",
                       "database. History logging moved to new session",
                                                 self.session_number)
                 try:
                     # Try writing to the new session. If this fails, don't
                     # recurse
                     self._writeout_input_cache(conn)
                 except sqlite3.IntegrityError:
                     pass
             finally:
                 self.db_input_cache = []
 
         with self.db_output_cache_lock:
             try:
                 self._writeout_output_cache(conn)
             except sqlite3.IntegrityError:
                 print("!! Session/line number for output was not unique",
                       "in database. Output will not be stored.")
             finally:
                 self.db_output_cache = []
 
 
 class HistorySavingThread(threading.Thread):
     """This thread takes care of writing history to the database, so that
     the UI isn't held up while that happens.
 
     It waits for the HistoryManager's save_flag to be set, then writes out
     the history cache. The main thread is responsible for setting the flag when
     the cache size reaches a defined threshold."""
     daemon = True
     stop_now = False
     enabled = True
     def __init__(self, history_manager):
         super(HistorySavingThread, self).__init__(name="IPythonHistorySavingThread")
         self.history_manager = history_manager
         self.enabled = history_manager.enabled
         atexit.register(self.stop)
 
     @needs_sqlite
     def run(self):
         # We need a separate db connection per thread:
         try:
             self.db = sqlite3.connect(self.history_manager.hist_file,
                             **self.history_manager.connection_options
             )
             while True:
                 self.history_manager.save_flag.wait()
                 if self.stop_now:
                     self.db.close()
                     return
                 self.history_manager.save_flag.clear()
                 self.history_manager.writeout_cache(self.db)
         except Exception as e:
             print(("The history saving thread hit an unexpected error (%s)."
                    "History will not be written to the database.") % repr(e))
 
     def stop(self):
         """This can be called from the main thread to safely stop this thread.
 
         Note that it does not attempt to write out remaining history before
         exiting. That should be done by calling the HistoryManager's
         end_session method."""
         self.stop_now = True
         self.history_manager.save_flag.set()
         self.join()
 
 
 # To match, e.g. ~5/8-~2/3
 range_re = re.compile(r"""
 ((?P<startsess>~?\d+)/)?
 (?P<start>\d+)?
 ((?P<sep>[\-:])
  ((?P<endsess>~?\d+)/)?
  (?P<end>\d+))?
 $""", re.VERBOSE)
 
 
 def extract_hist_ranges(ranges_str):
     """Turn a string of history ranges into 3-tuples of (session, start, stop).
 
     Examples
     --------
     >>> list(extract_hist_ranges("~8/5-~7/4 2"))
     [(-8, 5, None), (-7, 1, 5), (0, 2, 3)]
     """
     for range_str in ranges_str.split():
         rmatch = range_re.match(range_str)
         if not rmatch:
             continue
         start = rmatch.group("start")
         if start:
             start = int(start)
             end = rmatch.group("end")
             # If no end specified, get (a, a + 1)
             end = int(end) if end else start + 1
         else:  # start not specified
             if not rmatch.group('startsess'):  # no startsess
                 continue
             start = 1
             end = None  # provide the entire session hist
 
         if rmatch.group("sep") == "-":       # 1-3 == 1:4 --> [1, 2, 3]
             end += 1
         startsess = rmatch.group("startsess") or "0"
         endsess = rmatch.group("endsess") or startsess
         startsess = int(startsess.replace("~","-"))
         endsess = int(endsess.replace("~","-"))
         assert endsess >= startsess, "start session must be earlier than end session"
 
         if endsess == startsess:
             yield (startsess, start, end)
             continue
         # Multiple sessions in one range:
         yield (startsess, start, None)
         for sess in range(startsess+1, endsess):
             yield (sess, 1, None)
         yield (endsess, 1, end)
 
 
 def _format_lineno(session, line):
     """Helper function to format line numbers properly."""
     if session == 0:
         return str(line)
     return "%s#%s" % (session, line)
 
 

IPython/core/magic.py

@@ -1,702 +1,702 b''
 # encoding: utf-8
 """Magic functions for InteractiveShell.
 """
 from __future__ import print_function
 
 #-----------------------------------------------------------------------------
 #  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 decorator import decorator
 from IPython.utils.ipstruct import Struct
 from IPython.utils.process import arg_split
 from IPython.utils.py3compat import string_types, iteritems
 from IPython.utils.text import dedent
 from IPython.utils.traitlets import Bool, Dict, Instance, MetaHasTraits
 from IPython.utils.warn import error
 
 #-----------------------------------------------------------------------------
 # 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.__name__
             retval = decorator(call, func)
             record_magic(magics, magic_kind, name, name)
         elif isinstance(arg, string_types):
             # Decorator called with arguments (@foo('bar'))
             name = arg
             def mark(func, *a, **kw):
                 record_magic(magics, magic_kind, name, 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.__name__
             ip.register_magic_function(func, magic_kind, name)
             retval = decorator(call, func)
         elif isinstance(arg, string_types):
             # 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')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
 
     auto_magic = Bool(True, config=True, help=
         "Automatically call line magics without requiring explicit % prefix")
 
     def _auto_magic_changed(self, name, value):
         self.shell.automagic = value
     
     _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')
+    user_magics = Instance('IPython.core.magics.UserMagics', allow_none=True)
 
     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(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 iteritems(self.magics[m_type]):
                 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.__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)
 
     def register_alias(self, alias_name, magic_name, magic_kind='line'):
         """Register an alias to a magic function.
 
         The alias is an instance of :class:`MagicAlias`, which holds the
         name and kind of the magic it should call. Binding is done at
         call time, so if the underlying magic function is changed the alias
         will call the new function.
 
         Parameters
         ----------
         alias_name : str
           The name of the magic to be registered.
 
         magic_name : str
           The name of an existing magic.
 
         magic_kind : str
           Kind of magic, one of 'line' or 'cell'
         """
 
         # `validate_type` is too permissive, as it allows 'line_cell'
         # which we do not handle.
         if magic_kind not in magic_kinds:
             raise ValueError('magic_kind must be one of %s, %s given' %
                              magic_kinds, magic_kind)
 
         alias = MagicAlias(self.shell, magic_name, magic_kind)
         setattr(self.user_magics, alias_name, alias)
         record_magic(self.magics, magic_kind, alias_name, alias)
 
 # Key base class that provides the central functionality for magics.
 
 
 class Magics(Configurable):
     """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=None, **kwargs):
         if not(self.__class__.registered):
             raise ValueError('Magics subclass without registration - '
                              'did you forget to apply @magics_class?')
         if shell is not None:
             if hasattr(shell, 'configurables'):
                 shell.configurables.append(self)
             if hasattr(shell, 'config'):
                 kwargs.setdefault('parent', shell)
             kwargs['shell'] = shell
 
         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 iteritems(cls_tab):
                 if isinstance(meth_name, string_types):
                     # 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
         # Configurable **needs** to be initiated at the end or the config
         # magics get screwed up.
         super(Magics, self).__init__(**kwargs)
 
     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 :func:`getopt.getopt`, but it
         returns a :class:`~IPython.utils.struct.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.
 
         Parameters
         ----------
 
         arg_str : str
           The arguments to parse.
 
         opt_str : str
           The options specification.
 
         mode : str, default 'string'
           If given as 'list', the argument string is returned as a list (split
           on whitespace) instead of a string.
 
         list_all : bool, default False
           Put all option values in lists. Normally only options
           appearing more than once are put in a list.
 
         posix : bool, default True
           Whether to split the input line in POSIX mode or not, as per the
           conventions outlined in the :mod:`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 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
 
 
 class MagicAlias(object):
     """An alias to another magic function.
 
     An alias is determined by its magic name and magic kind. Lookup
     is done at call time, so if the underlying magic changes the alias
     will call the new function.
 
     Use the :meth:`MagicsManager.register_alias` method or the
     `%alias_magic` magic function to create and register a new alias.
     """
     def __init__(self, shell, magic_name, magic_kind):
         self.shell = shell
         self.magic_name = magic_name
         self.magic_kind = magic_kind
 
         self.pretty_target = '%s%s' % (magic_escapes[self.magic_kind], self.magic_name)
         self.__doc__ = "Alias for `%s`." % self.pretty_target
 
         self._in_call = False
 
     def __call__(self, *args, **kwargs):
         """Call the magic alias."""
         fn = self.shell.find_magic(self.magic_name, self.magic_kind)
         if fn is None:
             raise UsageError("Magic `%s` not found." % self.pretty_target)
 
         # Protect against infinite recursion.
         if self._in_call:
             raise UsageError("Infinite recursion detected; "
                              "magic aliases cannot call themselves.")
         self._in_call = True
         try:
             return fn(*args, **kwargs)
         finally:
             self._in_call = False

IPython/core/prefilter.py

@@ -1,715 +1,715 b''
 # encoding: utf-8
 """
 Prefiltering components.
 
 Prefilters transform user input before it is exec'd by Python.  These
 transforms are used to implement additional syntax such as !ls and %magic.
 
 Authors:
 
 * Brian Granger
 * Fernando Perez
 * Dan Milstein
 * Ville Vainio
 """
 
 #-----------------------------------------------------------------------------
 #  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 keyword import iskeyword
 import re
 
 from IPython.core.autocall import IPyAutocall
 from IPython.config.configurable import Configurable
 from IPython.core.inputsplitter import (
     ESC_MAGIC,
     ESC_QUOTE,
     ESC_QUOTE2,
     ESC_PAREN,
 )
 from IPython.core.macro import Macro
 from IPython.core.splitinput import LineInfo
 
 from IPython.utils.traitlets import (
     List, Integer, Unicode, CBool, Bool, Instance, CRegExp
 )
 
 #-----------------------------------------------------------------------------
 # Global utilities, errors and constants
 #-----------------------------------------------------------------------------
 
 
 class PrefilterError(Exception):
     pass
 
 
 # RegExp to identify potential function names
 re_fun_name = re.compile(r'[a-zA-Z_]([a-zA-Z0-9_.]*) *$')
 
 # RegExp to exclude strings with this start from autocalling.  In
 # particular, all binary operators should be excluded, so that if foo is
 # callable, foo OP bar doesn't become foo(OP bar), which is invalid.  The
 # characters '!=()' don't need to be checked for, as the checkPythonChars
 # routine explicitely does so, to catch direct calls and rebindings of
 # existing names.
 
 # Warning: the '-' HAS TO BE AT THE END of the first group, otherwise
 # it affects the rest of the group in square brackets.
 re_exclude_auto = re.compile(r'^[,&^\|\*/\+-]'
                              r'|^is |^not |^in |^and |^or ')
 
 # try to catch also methods for stuff in lists/tuples/dicts: off
 # (experimental). For this to work, the line_split regexp would need
 # to be modified so it wouldn't break things at '['. That line is
 # nasty enough that I shouldn't change it until I can test it _well_.
 #self.re_fun_name = re.compile (r'[a-zA-Z_]([a-zA-Z0-9_.\[\]]*) ?$')
 
 
 # Handler Check Utilities
 def is_shadowed(identifier, ip):
     """Is the given identifier defined in one of the namespaces which shadow
     the alias and magic namespaces?  Note that an identifier is different
     than ifun, because it can not contain a '.' character."""
     # This is much safer than calling ofind, which can change state
     return (identifier in ip.user_ns \
             or identifier in ip.user_global_ns \
             or identifier in ip.ns_table['builtin']\
             or iskeyword(identifier))
 
 
 #-----------------------------------------------------------------------------
 # Main Prefilter manager
 #-----------------------------------------------------------------------------
 
 
 class PrefilterManager(Configurable):
     """Main prefilter component.
 
     The IPython prefilter is run on all user input before it is run.  The
     prefilter consumes lines of input and produces transformed lines of
     input.
 
     The iplementation consists of two phases:
 
     1. Transformers
     2. Checkers and handlers
 
     Over time, we plan on deprecating the checkers and handlers and doing
     everything in the transformers.
 
     The transformers are instances of :class:`PrefilterTransformer` and have
     a single method :meth:`transform` that takes a line and returns a
     transformed line.  The transformation can be accomplished using any
     tool, but our current ones use regular expressions for speed.
 
     After all the transformers have been run, the line is fed to the checkers,
     which are instances of :class:`PrefilterChecker`.  The line is passed to
     the :meth:`check` method, which either returns `None` or a
     :class:`PrefilterHandler` instance.  If `None` is returned, the other
     checkers are tried.  If an :class:`PrefilterHandler` instance is returned,
     the line is passed to the :meth:`handle` method of the returned
     handler and no further checkers are tried.
 
     Both transformers and checkers have a `priority` attribute, that determines
     the order in which they are called.  Smaller priorities are tried first.
 
     Both transformers and checkers also have `enabled` attribute, which is
     a boolean that determines if the instance is used.
 
     Users or developers can change the priority or enabled attribute of
     transformers or checkers, but they must call the :meth:`sort_checkers`
     or :meth:`sort_transformers` method after changing the priority.
     """
 
     multi_line_specials = CBool(True, config=True)
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
 
     def __init__(self, shell=None, **kwargs):
         super(PrefilterManager, self).__init__(shell=shell, **kwargs)
         self.shell = shell
         self.init_transformers()
         self.init_handlers()
         self.init_checkers()
 
     #-------------------------------------------------------------------------
     # API for managing transformers
     #-------------------------------------------------------------------------
 
     def init_transformers(self):
         """Create the default transformers."""
         self._transformers = []
         for transformer_cls in _default_transformers:
             transformer_cls(
                 shell=self.shell, prefilter_manager=self, parent=self
             )
 
     def sort_transformers(self):
         """Sort the transformers by priority.
 
         This must be called after the priority of a transformer is changed.
         The :meth:`register_transformer` method calls this automatically.
         """
         self._transformers.sort(key=lambda x: x.priority)
 
     @property
     def transformers(self):
         """Return a list of checkers, sorted by priority."""
         return self._transformers
 
     def register_transformer(self, transformer):
         """Register a transformer instance."""
         if transformer not in self._transformers:
             self._transformers.append(transformer)
             self.sort_transformers()
 
     def unregister_transformer(self, transformer):
         """Unregister a transformer instance."""
         if transformer in self._transformers:
             self._transformers.remove(transformer)
 
     #-------------------------------------------------------------------------
     # API for managing checkers
     #-------------------------------------------------------------------------
 
     def init_checkers(self):
         """Create the default checkers."""
         self._checkers = []
         for checker in _default_checkers:
             checker(
                 shell=self.shell, prefilter_manager=self, parent=self
             )
 
     def sort_checkers(self):
         """Sort the checkers by priority.
 
         This must be called after the priority of a checker is changed.
         The :meth:`register_checker` method calls this automatically.
         """
         self._checkers.sort(key=lambda x: x.priority)
 
     @property
     def checkers(self):
         """Return a list of checkers, sorted by priority."""
         return self._checkers
 
     def register_checker(self, checker):
         """Register a checker instance."""
         if checker not in self._checkers:
             self._checkers.append(checker)
             self.sort_checkers()
 
     def unregister_checker(self, checker):
         """Unregister a checker instance."""
         if checker in self._checkers:
             self._checkers.remove(checker)
 
     #-------------------------------------------------------------------------
     # API for managing handlers
     #-------------------------------------------------------------------------
 
     def init_handlers(self):
         """Create the default handlers."""
         self._handlers = {}
         self._esc_handlers = {}
         for handler in _default_handlers:
             handler(
                 shell=self.shell, prefilter_manager=self, parent=self
             )
 
     @property
     def handlers(self):
         """Return a dict of all the handlers."""
         return self._handlers
 
     def register_handler(self, name, handler, esc_strings):
         """Register a handler instance by name with esc_strings."""
         self._handlers[name] = handler
         for esc_str in esc_strings:
             self._esc_handlers[esc_str] = handler
 
     def unregister_handler(self, name, handler, esc_strings):
         """Unregister a handler instance by name with esc_strings."""
         try:
             del self._handlers[name]
         except KeyError:
             pass
         for esc_str in esc_strings:
             h = self._esc_handlers.get(esc_str)
             if h is handler:
                 del self._esc_handlers[esc_str]
 
     def get_handler_by_name(self, name):
         """Get a handler by its name."""
         return self._handlers.get(name)
 
     def get_handler_by_esc(self, esc_str):
         """Get a handler by its escape string."""
         return self._esc_handlers.get(esc_str)
 
     #-------------------------------------------------------------------------
     # Main prefiltering API
     #-------------------------------------------------------------------------
 
     def prefilter_line_info(self, line_info):
         """Prefilter a line that has been converted to a LineInfo object.
 
         This implements the checker/handler part of the prefilter pipe.
         """
         # print "prefilter_line_info: ", line_info
         handler = self.find_handler(line_info)
         return handler.handle(line_info)
 
     def find_handler(self, line_info):
         """Find a handler for the line_info by trying checkers."""
         for checker in self.checkers:
             if checker.enabled:
                 handler = checker.check(line_info)
                 if handler:
                     return handler
         return self.get_handler_by_name('normal')
 
     def transform_line(self, line, continue_prompt):
         """Calls the enabled transformers in order of increasing priority."""
         for transformer in self.transformers:
             if transformer.enabled:
                 line = transformer.transform(line, continue_prompt)
         return line
 
     def prefilter_line(self, line, continue_prompt=False):
         """Prefilter a single input line as text.
 
         This method prefilters a single line of text by calling the
         transformers and then the checkers/handlers.
         """
 
         # print "prefilter_line: ", line, continue_prompt
         # All handlers *must* return a value, even if it's blank ('').
 
         # save the line away in case we crash, so the post-mortem handler can
         # record it
         self.shell._last_input_line = line
 
         if not line:
             # Return immediately on purely empty lines, so that if the user
             # previously typed some whitespace that started a continuation
             # prompt, he can break out of that loop with just an empty line.
             # This is how the default python prompt works.
             return ''
 
         # At this point, we invoke our transformers.
         if not continue_prompt or (continue_prompt and self.multi_line_specials):
             line = self.transform_line(line, continue_prompt)
 
         # Now we compute line_info for the checkers and handlers
         line_info = LineInfo(line, continue_prompt)
 
         # the input history needs to track even empty lines
         stripped = line.strip()
 
         normal_handler = self.get_handler_by_name('normal')
         if not stripped:
             return normal_handler.handle(line_info)
 
         # special handlers are only allowed for single line statements
         if continue_prompt and not self.multi_line_specials:
             return normal_handler.handle(line_info)
 
         prefiltered = self.prefilter_line_info(line_info)
         # print "prefiltered line: %r" % prefiltered
         return prefiltered
 
     def prefilter_lines(self, lines, continue_prompt=False):
         """Prefilter multiple input lines of text.
 
         This is the main entry point for prefiltering multiple lines of
         input.  This simply calls :meth:`prefilter_line` for each line of
         input.
 
         This covers cases where there are multiple lines in the user entry,
         which is the case when the user goes back to a multiline history
         entry and presses enter.
         """
         llines = lines.rstrip('\n').split('\n')
         # We can get multiple lines in one shot, where multiline input 'blends'
         # into one line, in cases like recalling from the readline history
         # buffer.  We need to make sure that in such cases, we correctly
         # communicate downstream which line is first and which are continuation
         # ones.
         if len(llines) > 1:
             out = '\n'.join([self.prefilter_line(line, lnum>0)
                              for lnum, line in enumerate(llines) ])
         else:
             out = self.prefilter_line(llines[0], continue_prompt)
 
         return out
 
 #-----------------------------------------------------------------------------
 # Prefilter transformers
 #-----------------------------------------------------------------------------
 
 
 class PrefilterTransformer(Configurable):
     """Transform a line of user input."""
 
     priority = Integer(100, config=True)
     # Transformers don't currently use shell or prefilter_manager, but as we
     # move away from checkers and handlers, they will need them.
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
-    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
+    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager', allow_none=True)
     enabled = Bool(True, config=True)
 
     def __init__(self, shell=None, prefilter_manager=None, **kwargs):
         super(PrefilterTransformer, self).__init__(
             shell=shell, prefilter_manager=prefilter_manager, **kwargs
         )
         self.prefilter_manager.register_transformer(self)
 
     def transform(self, line, continue_prompt):
         """Transform a line, returning the new one."""
         return None
 
     def __repr__(self):
         return "<%s(priority=%r, enabled=%r)>" % (
             self.__class__.__name__, self.priority, self.enabled)
 
 
 #-----------------------------------------------------------------------------
 # Prefilter checkers
 #-----------------------------------------------------------------------------
 
 
 class PrefilterChecker(Configurable):
     """Inspect an input line and return a handler for that line."""
 
     priority = Integer(100, config=True)
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
-    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
+    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager', allow_none=True)
     enabled = Bool(True, config=True)
 
     def __init__(self, shell=None, prefilter_manager=None, **kwargs):
         super(PrefilterChecker, self).__init__(
             shell=shell, prefilter_manager=prefilter_manager, **kwargs
         )
         self.prefilter_manager.register_checker(self)
 
     def check(self, line_info):
         """Inspect line_info and return a handler instance or None."""
         return None
 
     def __repr__(self):
         return "<%s(priority=%r, enabled=%r)>" % (
             self.__class__.__name__, self.priority, self.enabled)
 
 
 class EmacsChecker(PrefilterChecker):
 
     priority = Integer(100, config=True)
     enabled = Bool(False, config=True)
 
     def check(self, line_info):
         "Emacs ipython-mode tags certain input lines."
         if line_info.line.endswith('# PYTHON-MODE'):
             return self.prefilter_manager.get_handler_by_name('emacs')
         else:
             return None
 
 
 class MacroChecker(PrefilterChecker):
 
     priority = Integer(250, config=True)
 
     def check(self, line_info):
         obj = self.shell.user_ns.get(line_info.ifun)
         if isinstance(obj, Macro):
             return self.prefilter_manager.get_handler_by_name('macro')
         else:
             return None
 
 
 class IPyAutocallChecker(PrefilterChecker):
 
     priority = Integer(300, config=True)
 
     def check(self, line_info):
         "Instances of IPyAutocall in user_ns get autocalled immediately"
         obj = self.shell.user_ns.get(line_info.ifun, None)
         if isinstance(obj, IPyAutocall):
             obj.set_ip(self.shell)
             return self.prefilter_manager.get_handler_by_name('auto')
         else:
             return None
 
 
 class AssignmentChecker(PrefilterChecker):
 
     priority = Integer(600, config=True)
 
     def check(self, line_info):
         """Check to see if user is assigning to a var for the first time, in
         which case we want to avoid any sort of automagic / autocall games.
 
         This allows users to assign to either alias or magic names true python
         variables (the magic/alias systems always take second seat to true
         python code).  E.g. ls='hi', or ls,that=1,2"""
         if line_info.the_rest:
             if line_info.the_rest[0] in '=,':
                 return self.prefilter_manager.get_handler_by_name('normal')
         else:
             return None
 
 
 class AutoMagicChecker(PrefilterChecker):
 
     priority = Integer(700, config=True)
 
     def check(self, line_info):
         """If the ifun is magic, and automagic is on, run it.  Note: normal,
         non-auto magic would already have been triggered via '%' in
         check_esc_chars. This just checks for automagic.  Also, before
         triggering the magic handler, make sure that there is nothing in the
         user namespace which could shadow it."""
         if not self.shell.automagic or not self.shell.find_magic(line_info.ifun):
             return None
 
         # We have a likely magic method.  Make sure we should actually call it.
         if line_info.continue_prompt and not self.prefilter_manager.multi_line_specials:
             return None
 
         head = line_info.ifun.split('.',1)[0]
         if is_shadowed(head, self.shell):
             return None
 
         return self.prefilter_manager.get_handler_by_name('magic')
 
 
 class PythonOpsChecker(PrefilterChecker):
 
     priority = Integer(900, config=True)
 
     def check(self, line_info):
         """If the 'rest' of the line begins with a function call or pretty much
         any python operator, we should simply execute the line (regardless of
         whether or not there's a possible autocall expansion).  This avoids
         spurious (and very confusing) geattr() accesses."""
         if line_info.the_rest and line_info.the_rest[0] in '!=()<>,+*/%^&|':
             return self.prefilter_manager.get_handler_by_name('normal')
         else:
             return None
 
 
 class AutocallChecker(PrefilterChecker):
 
     priority = Integer(1000, config=True)
 
     function_name_regexp = CRegExp(re_fun_name, config=True,
         help="RegExp to identify potential function names.")
     exclude_regexp = CRegExp(re_exclude_auto, config=True,
         help="RegExp to exclude strings with this start from autocalling.")
 
     def check(self, line_info):
         "Check if the initial word/function is callable and autocall is on."
         if not self.shell.autocall:
             return None
 
         oinfo = line_info.ofind(self.shell) # This can mutate state via getattr
         if not oinfo['found']:
             return None
 
         if callable(oinfo['obj']) \
                and (not self.exclude_regexp.match(line_info.the_rest)) \
                and self.function_name_regexp.match(line_info.ifun):
             return self.prefilter_manager.get_handler_by_name('auto')
         else:
             return None
 
 
 #-----------------------------------------------------------------------------
 # Prefilter handlers
 #-----------------------------------------------------------------------------
 
 
 class PrefilterHandler(Configurable):
 
     handler_name = Unicode('normal')
     esc_strings = List([])
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
-    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
+    prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager', allow_none=True)
 
     def __init__(self, shell=None, prefilter_manager=None, **kwargs):
         super(PrefilterHandler, self).__init__(
             shell=shell, prefilter_manager=prefilter_manager, **kwargs
         )
         self.prefilter_manager.register_handler(
             self.handler_name,
             self,
             self.esc_strings
         )
 
     def handle(self, line_info):
         # print "normal: ", line_info
         """Handle normal input lines. Use as a template for handlers."""
 
         # With autoindent on, we need some way to exit the input loop, and I
         # don't want to force the user to have to backspace all the way to
         # clear the line.  The rule will be in this case, that either two
         # lines of pure whitespace in a row, or a line of pure whitespace but
         # of a size different to the indent level, will exit the input loop.
         line = line_info.line
         continue_prompt = line_info.continue_prompt
 
         if (continue_prompt and
             self.shell.autoindent and
             line.isspace() and
             0 < abs(len(line) - self.shell.indent_current_nsp) <= 2):
             line = ''
 
         return line
 
     def __str__(self):
         return "<%s(name=%s)>" % (self.__class__.__name__, self.handler_name)
 
 
 class MacroHandler(PrefilterHandler):
     handler_name = Unicode("macro")
 
     def handle(self, line_info):
         obj = self.shell.user_ns.get(line_info.ifun)
         pre_space = line_info.pre_whitespace
         line_sep = "\n" + pre_space
         return pre_space + line_sep.join(obj.value.splitlines())
 
 
 class MagicHandler(PrefilterHandler):
 
     handler_name = Unicode('magic')
     esc_strings = List([ESC_MAGIC])
 
     def handle(self, line_info):
         """Execute magic functions."""
         ifun    = line_info.ifun
         the_rest = line_info.the_rest
         cmd = '%sget_ipython().magic(%r)' % (line_info.pre_whitespace,
                                                     (ifun + " " + the_rest))
         return cmd
 
 
 class AutoHandler(PrefilterHandler):
 
     handler_name = Unicode('auto')
     esc_strings = List([ESC_PAREN, ESC_QUOTE, ESC_QUOTE2])
 
     def handle(self, line_info):
         """Handle lines which can be auto-executed, quoting if requested."""
         line    = line_info.line
         ifun    = line_info.ifun
         the_rest = line_info.the_rest
         pre     = line_info.pre
         esc     = line_info.esc
         continue_prompt = line_info.continue_prompt
         obj = line_info.ofind(self.shell)['obj']
         #print 'pre <%s> ifun <%s> rest <%s>' % (pre,ifun,the_rest)  # dbg
 
         # This should only be active for single-line input!
         if continue_prompt:
             return line
 
         force_auto = isinstance(obj, IPyAutocall)
 
         # User objects sometimes raise exceptions on attribute access other
         # than AttributeError (we've seen it in the past), so it's safest to be
         # ultra-conservative here and catch all.
         try:
             auto_rewrite = obj.rewrite
         except Exception:
             auto_rewrite = True
 
         if esc == ESC_QUOTE:
             # Auto-quote splitting on whitespace
             newcmd = '%s("%s")' % (ifun,'", "'.join(the_rest.split()) )
         elif esc == ESC_QUOTE2:
             # Auto-quote whole string
             newcmd = '%s("%s")' % (ifun,the_rest)
         elif esc == ESC_PAREN:
             newcmd = '%s(%s)' % (ifun,",".join(the_rest.split()))
         else:
             # Auto-paren.       
             if force_auto:
                 # Don't rewrite if it is already a call.
                 do_rewrite = not the_rest.startswith('(')
             else:
                 if not the_rest:
                     # We only apply it to argument-less calls if the autocall
                     # parameter is set to 2.
                     do_rewrite = (self.shell.autocall >= 2)
                 elif the_rest.startswith('[') and hasattr(obj, '__getitem__'):
                     # Don't autocall in this case: item access for an object
                     # which is BOTH callable and implements __getitem__.
                     do_rewrite = False
                 else:
                     do_rewrite = True
 
             # Figure out the rewritten command
             if do_rewrite:
                 if the_rest.endswith(';'):
                     newcmd = '%s(%s);' % (ifun.rstrip(),the_rest[:-1])
                 else:
                     newcmd = '%s(%s)' % (ifun.rstrip(), the_rest)                
             else:
                 normal_handler = self.prefilter_manager.get_handler_by_name('normal')
                 return normal_handler.handle(line_info)
         
         # Display the rewritten call
         if auto_rewrite:
             self.shell.auto_rewrite_input(newcmd)
 
         return newcmd
 
 
 class EmacsHandler(PrefilterHandler):
 
     handler_name = Unicode('emacs')
     esc_strings = List([])
 
     def handle(self, line_info):
         """Handle input lines marked by python-mode."""
 
         # Currently, nothing is done.  Later more functionality can be added
         # here if needed.
 
         # The input cache shouldn't be updated
         return line_info.line
 
 
 #-----------------------------------------------------------------------------
 # Defaults
 #-----------------------------------------------------------------------------
 
 
 _default_transformers = [
 ]
 
 _default_checkers = [
     EmacsChecker,
     MacroChecker,
     IPyAutocallChecker,
     AssignmentChecker,
     AutoMagicChecker,
     PythonOpsChecker,
     AutocallChecker
 ]
 
 _default_handlers = [
     PrefilterHandler,
     MacroHandler,
     MagicHandler,
     AutoHandler,
     EmacsHandler
 ]

IPython/core/prompts.py

@@ -1,442 +1,442 b''
 # -*- coding: utf-8 -*-
 """Classes for handling input/output prompts.
 
 Authors:
 
 * Fernando Perez
 * Brian Granger
 * Thomas Kluyver
 """
 
 #-----------------------------------------------------------------------------
 #       Copyright (C) 2008-2011 The IPython Development Team
 #       Copyright (C) 2001-2007 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.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import re
 import socket
 import sys
 import time
 
 from string import Formatter
 
 from IPython.config.configurable import Configurable
 from IPython.core import release
 from IPython.utils import coloransi, py3compat
 from IPython.utils.traitlets import (Unicode, Instance, Dict, Bool, Int)
 
 #-----------------------------------------------------------------------------
 # Color schemes for prompts
 #-----------------------------------------------------------------------------
 
 InputColors = coloransi.InputTermColors  # just a shorthand
 Colors = coloransi.TermColors  # just a shorthand
 
 color_lists = dict(normal=Colors(), inp=InputColors(), nocolor=coloransi.NoColors())
 
 PColNoColors = coloransi.ColorScheme(
     'NoColor',
     in_prompt  = InputColors.NoColor,  # Input prompt
     in_number  = InputColors.NoColor,  # Input prompt number
     in_prompt2 = InputColors.NoColor, # Continuation prompt
     in_normal  = InputColors.NoColor,  # color off (usu. Colors.Normal)
 
     out_prompt = Colors.NoColor, # Output prompt
     out_number = Colors.NoColor, # Output prompt number
 
     normal = Colors.NoColor  # color off (usu. Colors.Normal)
     )
 
 # make some schemes as instances so we can copy them for modification easily:
 PColLinux =  coloransi.ColorScheme(
     'Linux',
     in_prompt  = InputColors.Green,
     in_number  = InputColors.LightGreen,
     in_prompt2 = InputColors.Green,
     in_normal  = InputColors.Normal,  # color off (usu. Colors.Normal)
 
     out_prompt = Colors.Red,
     out_number = Colors.LightRed,
 
     normal = Colors.Normal
     )
 
 # Slightly modified Linux for light backgrounds
 PColLightBG  = PColLinux.copy('LightBG')
 
 PColLightBG.colors.update(
     in_prompt  = InputColors.Blue,
     in_number  = InputColors.LightBlue,
     in_prompt2 = InputColors.Blue
 )
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 class LazyEvaluate(object):
     """This is used for formatting strings with values that need to be updated
     at that time, such as the current time or working directory."""
     def __init__(self, func, *args, **kwargs):
         self.func = func
         self.args = args
         self.kwargs = kwargs
     
     def __call__(self, **kwargs):
         self.kwargs.update(kwargs)
         return self.func(*self.args, **self.kwargs)
     
     def __str__(self):
         return str(self())
     
     def __unicode__(self):
         return py3compat.unicode_type(self())
     
     def __format__(self, format_spec):
         return format(self(), format_spec)
 
 def multiple_replace(dict, text):
     """ Replace in 'text' all occurences of any key in the given
     dictionary by its corresponding value.  Returns the new string."""
 
     # Function by Xavier Defrang, originally found at:
     # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/81330
 
     # Create a regular expression  from the dictionary keys
     regex = re.compile("(%s)" % "|".join(map(re.escape, dict.keys())))
     # For each match, look-up corresponding value in dictionary
     return regex.sub(lambda mo: dict[mo.string[mo.start():mo.end()]], text)
 
 #-----------------------------------------------------------------------------
 # Special characters that can be used in prompt templates, mainly bash-like
 #-----------------------------------------------------------------------------
 
 # If $HOME isn't defined (Windows), make it an absurd string so that it can
 # never be expanded out into '~'.  Basically anything which can never be a
 # reasonable directory name will do, we just want the $HOME -> '~' operation
 # to become a no-op.  We pre-compute $HOME here so it's not done on every
 # prompt call.
 
 # FIXME:
 
 # - This should be turned into a class which does proper namespace management,
 # since the prompt specials need to be evaluated in a certain namespace.
 # Currently it's just globals, which need to be managed manually by code
 # below.
 
 # - I also need to split up the color schemes from the prompt specials
 # somehow.  I don't have a clean design for that quite yet.
 
 HOME = py3compat.str_to_unicode(os.environ.get("HOME","//////:::::ZZZZZ,,,~~~"))
 
 # This is needed on FreeBSD, and maybe other systems which symlink /home to
 # /usr/home, but retain the $HOME variable as pointing to /home
 HOME = os.path.realpath(HOME)
 
 # We precompute a few more strings here for the prompt_specials, which are
 # fixed once ipython starts.  This reduces the runtime overhead of computing
 # prompt strings.
 USER           = py3compat.str_to_unicode(os.environ.get("USER",''))
 HOSTNAME       = py3compat.str_to_unicode(socket.gethostname())
 HOSTNAME_SHORT = HOSTNAME.split(".")[0]
 
 # IronPython doesn't currently have os.getuid() even if 
 # os.name == 'posix'; 2/8/2014
 ROOT_SYMBOL    = "#" if (os.name=='nt' or sys.platform=='cli' or os.getuid()==0) else "$"
 
 prompt_abbreviations = {
     # Prompt/history count
     '%n' : '{color.number}' '{count}' '{color.prompt}',
     r'\#': '{color.number}' '{count}' '{color.prompt}',
     # Just the prompt counter number, WITHOUT any coloring wrappers, so users
     # can get numbers displayed in whatever color they want.
     r'\N': '{count}',
 
     # Prompt/history count, with the actual digits replaced by dots.  Used
     # mainly in continuation prompts (prompt_in2)
     r'\D': '{dots}',
 
     # Current time
     r'\T' : '{time}',
     # Current working directory
     r'\w': '{cwd}',
     # Basename of current working directory.
     # (use os.sep to make this portable across OSes)
     r'\W' : '{cwd_last}',
     # These X<N> are an extension to the normal bash prompts.  They return
     # N terms of the path, after replacing $HOME with '~'
     r'\X0': '{cwd_x[0]}',
     r'\X1': '{cwd_x[1]}',
     r'\X2': '{cwd_x[2]}',
     r'\X3': '{cwd_x[3]}',
     r'\X4': '{cwd_x[4]}',
     r'\X5': '{cwd_x[5]}',
     # Y<N> are similar to X<N>, but they show '~' if it's the directory
     # N+1 in the list.  Somewhat like %cN in tcsh.
     r'\Y0': '{cwd_y[0]}',
     r'\Y1': '{cwd_y[1]}',
     r'\Y2': '{cwd_y[2]}',
     r'\Y3': '{cwd_y[3]}',
     r'\Y4': '{cwd_y[4]}',
     r'\Y5': '{cwd_y[5]}',
     # Hostname up to first .
     r'\h': HOSTNAME_SHORT,
     # Full hostname
     r'\H': HOSTNAME,
     # Username of current user
     r'\u': USER,
     # Escaped '\'
     '\\\\': '\\',
     # Newline
     r'\n': '\n',
     # Carriage return
     r'\r': '\r',
     # Release version
     r'\v': release.version,
     # Root symbol ($ or #)
     r'\$': ROOT_SYMBOL,
     }
 
 #-----------------------------------------------------------------------------
 # More utilities
 #-----------------------------------------------------------------------------
 
 def cwd_filt(depth):
     """Return the last depth elements of the current working directory.
 
     $HOME is always replaced with '~'.
     If depth==0, the full path is returned."""
 
     cwd = py3compat.getcwd().replace(HOME,"~")
     out = os.sep.join(cwd.split(os.sep)[-depth:])
     return out or os.sep
 
 def cwd_filt2(depth):
     """Return the last depth elements of the current working directory.
 
     $HOME is always replaced with '~'.
     If depth==0, the full path is returned."""
 
     full_cwd = py3compat.getcwd()
     cwd = full_cwd.replace(HOME,"~").split(os.sep)
     if '~' in cwd and len(cwd) == depth+1:
         depth += 1
     drivepart = ''
     if sys.platform == 'win32' and len(cwd) > depth:
         drivepart = os.path.splitdrive(full_cwd)[0]
     out = drivepart + '/'.join(cwd[-depth:])
 
     return out or os.sep
 
 #-----------------------------------------------------------------------------
 # Prompt classes
 #-----------------------------------------------------------------------------
 
 lazily_evaluate = {'time': LazyEvaluate(time.strftime, "%H:%M:%S"),
                    'cwd': LazyEvaluate(py3compat.getcwd),
                    'cwd_last': LazyEvaluate(lambda: py3compat.getcwd().split(os.sep)[-1]),
                    'cwd_x': [LazyEvaluate(lambda: py3compat.getcwd().replace(HOME,"~"))] +\
                             [LazyEvaluate(cwd_filt, x) for x in range(1,6)],
                    'cwd_y': [LazyEvaluate(cwd_filt2, x) for x in range(6)]
                    }
 
 def _lenlastline(s):
     """Get the length of the last line. More intelligent than
     len(s.splitlines()[-1]).
     """
     if not s or s.endswith(('\n', '\r')):
         return 0
     return len(s.splitlines()[-1])
 
 
 class UserNSFormatter(Formatter):
     """A Formatter that falls back on a shell's user_ns and __builtins__ for name resolution"""
     def __init__(self, shell):
         self.shell = shell
 
     def get_value(self, key, args, kwargs):
         # try regular formatting first:
         try:
             return Formatter.get_value(self, key, args, kwargs)
         except Exception:
             pass
         # next, look in user_ns and builtins:
         for container in (self.shell.user_ns, __builtins__):
             if key in container:
                 return container[key]
         # nothing found, put error message in its place
         return "<ERROR: '%s' not found>" % key
 
 
 class PromptManager(Configurable):
     """This is the primary interface for producing IPython's prompts."""
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', allow_none=True)
     
-    color_scheme_table = Instance(coloransi.ColorSchemeTable)
+    color_scheme_table = Instance(coloransi.ColorSchemeTable, allow_none=True)
     color_scheme = Unicode('Linux', config=True)
     def _color_scheme_changed(self, name, new_value):
         self.color_scheme_table.set_active_scheme(new_value)
         for pname in ['in', 'in2', 'out', 'rewrite']:
             # We need to recalculate the number of invisible characters
             self.update_prompt(pname)
     
     lazy_evaluate_fields = Dict(help="""
         This maps field names used in the prompt templates to functions which
         will be called when the prompt is rendered. This allows us to include
         things like the current time in the prompts. Functions are only called
         if they are used in the prompt.
         """)
     def _lazy_evaluate_fields_default(self): return lazily_evaluate.copy()
     
     in_template = Unicode('In [\\#]: ', config=True,
         help="Input prompt.  '\\#' will be transformed to the prompt number")
     in2_template = Unicode('   .\\D.: ', config=True,
         help="Continuation prompt.")
     out_template = Unicode('Out[\\#]: ', config=True,
         help="Output prompt. '\\#' will be transformed to the prompt number")
     
     justify = Bool(True, config=True, help="""
         If True (default), each prompt will be right-aligned with the
         preceding one.
         """)
     
     # We actually store the expanded templates here:
     templates = Dict()
     
     # The number of characters in the last prompt rendered, not including
     # colour characters.
     width = Int()
     txtwidth = Int()   # Not including right-justification
     
     # The number of characters in each prompt which don't contribute to width
     invisible_chars = Dict()
     def _invisible_chars_default(self):
         return {'in': 0, 'in2': 0, 'out': 0, 'rewrite':0}
     
     def __init__(self, shell, **kwargs):
         super(PromptManager, self).__init__(shell=shell, **kwargs)
         
         # Prepare colour scheme table
         self.color_scheme_table = coloransi.ColorSchemeTable([PColNoColors,
                                     PColLinux, PColLightBG], self.color_scheme)
         
         self._formatter = UserNSFormatter(shell)
         # Prepare templates & numbers of invisible characters
         self.update_prompt('in', self.in_template)
         self.update_prompt('in2', self.in2_template)
         self.update_prompt('out', self.out_template)
         self.update_prompt('rewrite')
         self.on_trait_change(self._update_prompt_trait, ['in_template',
                             'in2_template', 'out_template'])
     
     def update_prompt(self, name, new_template=None):
         """This is called when a prompt template is updated. It processes
         abbreviations used in the prompt template (like \#) and calculates how
         many invisible characters (ANSI colour escapes) the resulting prompt
         contains.
         
         It is also called for each prompt on changing the colour scheme. In both
         cases, traitlets should take care of calling this automatically.
         """
         if new_template is not None:
             self.templates[name] = multiple_replace(prompt_abbreviations, new_template)
         # We count invisible characters (colour escapes) on the last line of the
         # prompt, to calculate the width for lining up subsequent prompts.
         invis_chars = _lenlastline(self._render(name, color=True)) - \
                         _lenlastline(self._render(name, color=False))
         self.invisible_chars[name] = invis_chars
     
     def _update_prompt_trait(self, traitname, new_template):
         name = traitname[:-9]   # Cut off '_template'
         self.update_prompt(name, new_template)
     
     def _render(self, name, color=True, **kwargs):
         """Render but don't justify, or update the width or txtwidth attributes.
         """
         if name == 'rewrite':
             return self._render_rewrite(color=color)
         
         if color:
             scheme = self.color_scheme_table.active_colors
             if name=='out':
                 colors = color_lists['normal']
                 colors.number, colors.prompt, colors.normal = \
                         scheme.out_number, scheme.out_prompt, scheme.normal
             else:
                 colors = color_lists['inp']
                 colors.number, colors.prompt, colors.normal = \
                         scheme.in_number, scheme.in_prompt, scheme.in_normal
                 if name=='in2':
                     colors.prompt = scheme.in_prompt2
         else:
             # No color
             colors = color_lists['nocolor']
             colors.number, colors.prompt, colors.normal = '', '', ''
         
         count = self.shell.execution_count    # Shorthand
         # Build the dictionary to be passed to string formatting
         fmtargs = dict(color=colors, count=count,
                         dots="."*len(str(count)),
                         width=self.width, txtwidth=self.txtwidth )
         fmtargs.update(self.lazy_evaluate_fields)
         fmtargs.update(kwargs)
         
         # Prepare the prompt
         prompt = colors.prompt + self.templates[name] + colors.normal
         
         # Fill in required fields
         return self._formatter.format(prompt, **fmtargs)
     
     def _render_rewrite(self, color=True):
         """Render the ---> rewrite prompt."""
         if color:
             scheme = self.color_scheme_table.active_colors
             # We need a non-input version of these escapes
             color_prompt = scheme.in_prompt.replace("\001","").replace("\002","")
             color_normal = scheme.normal
         else:
             color_prompt, color_normal = '', ''
 
         return color_prompt + "-> ".rjust(self.txtwidth, "-") + color_normal
     
     def render(self, name, color=True, just=None, **kwargs):
         """
         Render the selected prompt.
         
         Parameters
         ----------
         name : str
           Which prompt to render. One of 'in', 'in2', 'out', 'rewrite'
         color : bool
           If True (default), include ANSI escape sequences for a coloured prompt.
         just : bool
           If True, justify the prompt to the width of the last prompt. The
           default is stored in self.justify.
         **kwargs :
           Additional arguments will be passed to the string formatting operation,
           so they can override the values that would otherwise fill in the
           template.
         
         Returns
         -------
         A string containing the rendered prompt.
         """
         res = self._render(name, color=color, **kwargs)
         
         # Handle justification of prompt
         invis_chars = self.invisible_chars[name] if color else 0
         self.txtwidth = _lenlastline(res) - invis_chars
         just = self.justify if (just is None) else just
         # If the prompt spans more than one line, don't try to justify it:
         if just and name != 'in' and ('\n' not in res) and ('\r' not in res):
             res = res.rjust(self.width + invis_chars)
         self.width = _lenlastline(res) - invis_chars
         return res

IPython/core/shellapp.py

@@ -1,432 +1,433 b''
 # encoding: utf-8
 """
 A mixin for :class:`~IPython.core.application.Application` classes that
 launch InteractiveShell instances, load extensions, etc.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import absolute_import
 from __future__ import print_function
 
 import glob
 import os
 import sys
 
 from IPython.config.application import boolean_flag
 from IPython.config.configurable import Configurable
 from IPython.config.loader import Config
 from IPython.core import pylabtools
 from IPython.utils import py3compat
 from IPython.utils.contexts import preserve_keys
 from IPython.utils.path import filefind
 from IPython.utils.traitlets import (
     Unicode, Instance, List, Bool, CaselessStrEnum
 )
 from IPython.lib.inputhook import guis
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 
 gui_keys = tuple(sorted([ key for key in guis if key is not None ]))
 
 backend_keys = sorted(pylabtools.backends.keys())
 backend_keys.insert(0, 'auto')
 
 shell_flags = {}
 
 addflag = lambda *args: shell_flags.update(boolean_flag(*args))
 addflag('autoindent', 'InteractiveShell.autoindent',
         'Turn on autoindenting.', 'Turn off autoindenting.'
 )
 addflag('automagic', 'InteractiveShell.automagic',
         """Turn on the auto calling of magic commands. Type %%magic at the
         IPython  prompt  for  more information.""",
         'Turn off the auto calling of magic commands.'
 )
 addflag('pdb', 'InteractiveShell.pdb',
     "Enable auto calling the pdb debugger after every exception.",
     "Disable auto calling the pdb debugger after every exception."
 )
 # pydb flag doesn't do any config, as core.debugger switches on import,
 # which is before parsing.  This just allows the flag to be passed.
 shell_flags.update(dict(
     pydb = ({},
         """Use the third party 'pydb' package as debugger, instead of pdb.
         Requires that pydb is installed."""
     )
 ))
 addflag('pprint', 'PlainTextFormatter.pprint',
     "Enable auto pretty printing of results.",
     "Disable auto pretty printing of results."
 )
 addflag('color-info', 'InteractiveShell.color_info',
     """IPython can display information about objects via a set of functions,
     and optionally can use colors for this, syntax highlighting
     source code and various other elements. This is on by default, but can cause
     problems with some pagers. If you see such problems, you can disable the
     colours.""",
     "Disable using colors for info related things."
 )
 addflag('deep-reload', 'InteractiveShell.deep_reload',
     """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(). This feature is off
     by default [which means that you have both normal reload() and
     dreload()].""",
     "Disable deep (recursive) reloading by default."
 )
 nosep_config = Config()
 nosep_config.InteractiveShell.separate_in = ''
 nosep_config.InteractiveShell.separate_out = ''
 nosep_config.InteractiveShell.separate_out2 = ''
 
 shell_flags['nosep']=(nosep_config, "Eliminate all spacing between prompts.")
 shell_flags['pylab'] = (
     {'InteractiveShellApp' : {'pylab' : 'auto'}},
     """Pre-load matplotlib and numpy for interactive use with
     the default matplotlib backend."""
 )
 shell_flags['matplotlib'] = (
     {'InteractiveShellApp' : {'matplotlib' : 'auto'}},
     """Configure matplotlib for interactive use with
     the default matplotlib backend."""
 )
 
 # it's possible we don't want short aliases for *all* of these:
 shell_aliases = dict(
     autocall='InteractiveShell.autocall',
     colors='InteractiveShell.colors',
     logfile='InteractiveShell.logfile',
     logappend='InteractiveShell.logappend',
     c='InteractiveShellApp.code_to_run',
     m='InteractiveShellApp.module_to_run',
     ext='InteractiveShellApp.extra_extension',
     gui='InteractiveShellApp.gui',
     pylab='InteractiveShellApp.pylab',
     matplotlib='InteractiveShellApp.matplotlib',
 )
 shell_aliases['cache-size'] = 'InteractiveShell.cache_size'
 
 #-----------------------------------------------------------------------------
 # Main classes and functions
 #-----------------------------------------------------------------------------
 
 class InteractiveShellApp(Configurable):
     """A Mixin for applications that start InteractiveShell instances.
     
     Provides configurables for loading extensions and executing files
     as part of configuring a Shell environment.
 
     The following methods should be called by the :meth:`initialize` method
     of the subclass:
 
       - :meth:`init_path`
       - :meth:`init_shell` (to be implemented by the subclass)
       - :meth:`init_gui_pylab`
       - :meth:`init_extensions`
       - :meth:`init_code`
     """
     extensions = List(Unicode, config=True,
         help="A list of dotted module names of IPython extensions to load."
     )
     extra_extension = Unicode('', config=True,
         help="dotted module name of an IPython extension to load."
     )
 
     reraise_ipython_extension_failures = Bool(
         False,
         config=True,
         help="Reraise exceptions encountered loading IPython extensions?",
     )
 
     # Extensions that are always loaded (not configurable)
     default_extensions = List(Unicode, [u'storemagic'], config=False)
     
     hide_initial_ns = Bool(True, config=True,
         help="""Should variables loaded at startup (by startup files, exec_lines, etc.)
         be hidden from tools like %who?"""
     )
 
     exec_files = List(Unicode, config=True,
         help="""List of files to run at IPython startup."""
     )
     exec_PYTHONSTARTUP = Bool(True, config=True,
         help="""Run the file referenced by the PYTHONSTARTUP environment
         variable at IPython startup."""
     )
     file_to_run = Unicode('', config=True,
         help="""A file to be run""")
 
     exec_lines = List(Unicode, config=True,
         help="""lines of code to run at IPython startup."""
     )
     code_to_run = Unicode('', config=True,
         help="Execute the given command string."
     )
     module_to_run = Unicode('', config=True,
         help="Run the module as a script."
     )
     gui = CaselessStrEnum(gui_keys, config=True, allow_none=True,
         help="Enable GUI event loop integration with any of {0}.".format(gui_keys)
     )
     matplotlib = CaselessStrEnum(backend_keys, allow_none=True,
         config=True,
         help="""Configure matplotlib for interactive use with
         the default matplotlib backend."""
     )
     pylab = CaselessStrEnum(backend_keys, allow_none=True,
         config=True,
         help="""Pre-load matplotlib and numpy for interactive use,
         selecting a particular matplotlib backend and loop integration.
         """
     )
     pylab_import_all = Bool(True, config=True,
         help="""If true, IPython will populate the user namespace with numpy, pylab, etc.
         and an ``import *`` is done from numpy and pylab, when using pylab mode.
         
         When False, pylab mode should not import any names into the user namespace.
         """
     )
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
+                     allow_none=True)
     
     user_ns = Instance(dict, args=None, allow_none=True)
     def _user_ns_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_ns = new
             self.shell.init_user_ns()
 
     def init_path(self):
         """Add current working directory, '', to sys.path"""
         if sys.path[0] != '':
             sys.path.insert(0, '')
 
     def init_shell(self):
         raise NotImplementedError("Override in subclasses")
 
     def init_gui_pylab(self):
         """Enable GUI event loop integration, taking pylab into account."""
         enable = False
         shell = self.shell
         if self.pylab:
             enable = lambda key: shell.enable_pylab(key, import_all=self.pylab_import_all)
             key = self.pylab
         elif self.matplotlib:
             enable = shell.enable_matplotlib
             key = self.matplotlib
         elif self.gui:
             enable = shell.enable_gui
             key = self.gui
         
         if not enable:
             return
         
         try:
             r = enable(key)
         except ImportError:
             self.log.warn("Eventloop or matplotlib integration failed. Is matplotlib installed?")
             self.shell.showtraceback()
             return
         except Exception:
             self.log.warn("GUI event loop or pylab initialization failed")
             self.shell.showtraceback()
             return
             
         if isinstance(r, tuple):
             gui, backend = r[:2]
             self.log.info("Enabling GUI event loop integration, "
                       "eventloop=%s, matplotlib=%s", gui, backend)
             if key == "auto":
                 print("Using matplotlib backend: %s" % backend)
         else:
             gui = r
             self.log.info("Enabling GUI event loop integration, "
                       "eventloop=%s", gui)
 
     def init_extensions(self):
         """Load all IPython extensions in IPythonApp.extensions.
 
         This uses the :meth:`ExtensionManager.load_extensions` to load all
         the extensions listed in ``self.extensions``.
         """
         try:
             self.log.debug("Loading IPython extensions...")
             extensions = self.default_extensions + self.extensions
             if self.extra_extension:
                 extensions.append(self.extra_extension)
             for ext in extensions:
                 try:
                     self.log.info("Loading IPython extension: %s" % ext)
                     self.shell.extension_manager.load_extension(ext)
                 except:
                     if self.reraise_ipython_extension_failures:
                         raise
                     msg = ("Error in loading extension: {ext}\n"
                            "Check your config files in {location}".format(
                                ext=ext,
                                location=self.profile_dir.location
                            ))
                     self.log.warn(msg, exc_info=True)
         except:
             if self.reraise_ipython_extension_failures:
                 raise
             self.log.warn("Unknown error in loading extensions:", exc_info=True)
 
     def init_code(self):
         """run the pre-flight code, specified via exec_lines"""
         self._run_startup_files()
         self._run_exec_lines()
         self._run_exec_files()
         
         # Hide variables defined here from %who etc.
         if self.hide_initial_ns:
             self.shell.user_ns_hidden.update(self.shell.user_ns)
         
         # command-line execution (ipython -i script.py, ipython -m module)
         # should *not* be excluded from %whos
         self._run_cmd_line_code()
         self._run_module()
         
         # flush output, so itwon't be attached to the first cell
         sys.stdout.flush()
         sys.stderr.flush()
 
     def _run_exec_lines(self):
         """Run lines of code in IPythonApp.exec_lines in the user's namespace."""
         if not self.exec_lines:
             return
         try:
             self.log.debug("Running code from IPythonApp.exec_lines...")
             for line in self.exec_lines:
                 try:
                     self.log.info("Running code in user namespace: %s" %
                                   line)
                     self.shell.run_cell(line, store_history=False)
                 except:
                     self.log.warn("Error in executing line in user "
                                   "namespace: %s" % line)
                     self.shell.showtraceback()
         except:
             self.log.warn("Unknown error in handling IPythonApp.exec_lines:")
             self.shell.showtraceback()
 
     def _exec_file(self, fname, shell_futures=False):
         try:
             full_filename = filefind(fname, [u'.', self.ipython_dir])
         except IOError as e:
             self.log.warn("File not found: %r"%fname)
             return
         # Make sure that the running script gets a proper sys.argv as if it
         # were run from a system shell.
         save_argv = sys.argv
         sys.argv = [full_filename] + self.extra_args[1:]
         # protect sys.argv from potential unicode strings on Python 2:
         if not py3compat.PY3:
             sys.argv = [ py3compat.cast_bytes(a) for a in sys.argv ]
         try:
             if os.path.isfile(full_filename):
                 self.log.info("Running file in user namespace: %s" %
                               full_filename)
                 # Ensure that __file__ is always defined to match Python
                 # behavior.
                 with preserve_keys(self.shell.user_ns, '__file__'):
                     self.shell.user_ns['__file__'] = fname
                     if full_filename.endswith('.ipy'):
                         self.shell.safe_execfile_ipy(full_filename,
                                                      shell_futures=shell_futures)
                     else:
                         # default to python, even without extension
                         self.shell.safe_execfile(full_filename,
                                                  self.shell.user_ns,
                                                  shell_futures=shell_futures)
         finally:
             sys.argv = save_argv
 
     def _run_startup_files(self):
         """Run files from profile startup directory"""
         startup_dir = self.profile_dir.startup_dir
         startup_files = []
         
         if self.exec_PYTHONSTARTUP and os.environ.get('PYTHONSTARTUP', False) and \
                 not (self.file_to_run or self.code_to_run or self.module_to_run):
             python_startup = os.environ['PYTHONSTARTUP']
             self.log.debug("Running PYTHONSTARTUP file %s...", python_startup)
             try:
                 self._exec_file(python_startup)
             except:
                 self.log.warn("Unknown error in handling PYTHONSTARTUP file %s:", python_startup)
                 self.shell.showtraceback()
             finally:
                 # Many PYTHONSTARTUP files set up the readline completions,
                 # but this is often at odds with IPython's own completions.
                 # Do not allow PYTHONSTARTUP to set up readline.
                 if self.shell.has_readline:
                     self.shell.set_readline_completer()
         
         startup_files += glob.glob(os.path.join(startup_dir, '*.py'))
         startup_files += glob.glob(os.path.join(startup_dir, '*.ipy'))
         if not startup_files:
             return
         
         self.log.debug("Running startup files from %s...", startup_dir)
         try:
             for fname in sorted(startup_files):
                 self._exec_file(fname)
         except:
             self.log.warn("Unknown error in handling startup files:")
             self.shell.showtraceback()
 
     def _run_exec_files(self):
         """Run files from IPythonApp.exec_files"""
         if not self.exec_files:
             return
 
         self.log.debug("Running files in IPythonApp.exec_files...")
         try:
             for fname in self.exec_files:
                 self._exec_file(fname)
         except:
             self.log.warn("Unknown error in handling IPythonApp.exec_files:")
             self.shell.showtraceback()
 
     def _run_cmd_line_code(self):
         """Run code or file specified at the command-line"""
         if self.code_to_run:
             line = self.code_to_run
             try:
                 self.log.info("Running code given at command line (c=): %s" %
                               line)
                 self.shell.run_cell(line, store_history=False)
             except:
                 self.log.warn("Error in executing line in user namespace: %s" %
                               line)
                 self.shell.showtraceback()
 
         # Like Python itself, ignore the second if the first of these is present
         elif self.file_to_run:
             fname = self.file_to_run
             try:
                 self._exec_file(fname, shell_futures=True)
             except:
                 self.log.warn("Error in executing file in user namespace: %s" %
                               fname)
                 self.shell.showtraceback()
 
     def _run_module(self):
         """Run module specified at the command-line."""
         if self.module_to_run:
             # Make sure that the module gets a proper sys.argv as if it were
             # run using `python -m`.
             save_argv = sys.argv
             sys.argv = [sys.executable] + self.extra_args
             try:
                 self.shell.safe_run_module(self.module_to_run,
                                            self.shell.user_ns)
             finally:
                 sys.argv = save_argv

IPython/html/notebookapp.py

@@ -1,1127 +1,1127 b''
 # coding: utf-8
 """A tornado based IPython notebook server."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import base64
 import datetime
 import errno
 import importlib
 import io
 import json
 import logging
 import os
 import random
 import re
 import select
 import signal
 import socket
 import sys
 import threading
 import webbrowser
 
 
 # check for pyzmq
 from IPython.utils.zmqrelated import check_for_zmq
 check_for_zmq('13', 'IPython.html')
 
 from jinja2 import Environment, FileSystemLoader
 
 # Install the pyzmq ioloop. This has to be done before anything else from
 # tornado is imported.
 from zmq.eventloop import ioloop
 ioloop.install()
 
 # check for tornado 3.1.0
 msg = "The IPython Notebook requires tornado >= 4.0"
 try:
     import tornado
 except ImportError:
     raise ImportError(msg)
 try:
     version_info = tornado.version_info
 except AttributeError:
     raise ImportError(msg + ", but you have < 1.1.0")
 if version_info < (4,0):
     raise ImportError(msg + ", but you have %s" % tornado.version)
 
 from tornado import httpserver
 from tornado import web
 from tornado.log import LogFormatter, app_log, access_log, gen_log
 
 from IPython.html import (
     DEFAULT_STATIC_FILES_PATH,
     DEFAULT_TEMPLATE_PATH_LIST,
 )
 from .base.handlers import Template404
 from .log import log_request
 from .services.kernels.kernelmanager import MappingKernelManager
 from .services.config import ConfigManager
 from .services.contents.manager import ContentsManager
 from .services.contents.filemanager import FileContentsManager
 from .services.clusters.clustermanager import ClusterManager
 from .services.sessions.sessionmanager import SessionManager
 
 from .auth.login import LoginHandler
 from .auth.logout import LogoutHandler
 from .base.handlers import IPythonHandler, FileFindHandler
 
 from IPython.config import Config
 from IPython.config.application import catch_config_error, boolean_flag
 from IPython.core.application import (
     BaseIPythonApplication, base_flags, base_aliases,
 )
 from IPython.core.profiledir import ProfileDir
 from IPython.kernel import KernelManager
 from IPython.kernel.kernelspec import KernelSpecManager
 from IPython.kernel.zmq.session import Session
 from IPython.nbformat.sign import NotebookNotary
 from IPython.utils.importstring import import_item
 from IPython.utils import submodule
 from IPython.utils.process import check_pid
 from IPython.utils.traitlets import (
     Dict, Unicode, Integer, List, Bool, Bytes, Instance,
     TraitError, Type,
 )
 from IPython.utils import py3compat
 from IPython.utils.path import filefind, get_ipython_dir
 from IPython.utils.sysinfo import get_sys_info
 
 from .nbextensions import SYSTEM_NBEXTENSIONS_DIRS
 from .utils import url_path_join
 
 #-----------------------------------------------------------------------------
 # Module globals
 #-----------------------------------------------------------------------------
 
 _examples = """
 ipython notebook                       # start the notebook
 ipython notebook --profile=sympy       # use the sympy profile
 ipython notebook --certfile=mycert.pem # use SSL/TLS certificate
 """
 
 #-----------------------------------------------------------------------------
 # Helper functions
 #-----------------------------------------------------------------------------
 
 def random_ports(port, n):
     """Generate a list of n random ports near the given port.
 
     The first 5 ports will be sequential, and the remaining n-5 will be
     randomly selected in the range [port-2*n, port+2*n].
     """
     for i in range(min(5, n)):
         yield port + i
     for i in range(n-5):
         yield max(1, port + random.randint(-2*n, 2*n))
 
 def load_handlers(name):
     """Load the (URL pattern, handler) tuples for each component."""
     name = 'IPython.html.' + name
     mod = __import__(name, fromlist=['default_handlers'])
     return mod.default_handlers
 
 #-----------------------------------------------------------------------------
 # The Tornado web application
 #-----------------------------------------------------------------------------
 
 class NotebookWebApplication(web.Application):
 
     def __init__(self, ipython_app, kernel_manager, contents_manager,
                  cluster_manager, session_manager, kernel_spec_manager,
                  config_manager, log,
                  base_url, default_url, settings_overrides, jinja_env_options):
 
         settings = self.init_settings(
             ipython_app, kernel_manager, contents_manager, cluster_manager,
             session_manager, kernel_spec_manager, config_manager, log, base_url,
             default_url, settings_overrides, jinja_env_options)
         handlers = self.init_handlers(settings)
 
         super(NotebookWebApplication, self).__init__(handlers, **settings)
 
     def init_settings(self, ipython_app, kernel_manager, contents_manager,
                       cluster_manager, session_manager, kernel_spec_manager,
                       config_manager,
                       log, base_url, default_url, settings_overrides,
                       jinja_env_options=None):
 
         _template_path = settings_overrides.get(
             "template_path",
             ipython_app.template_file_path,
         )
         if isinstance(_template_path, str):
             _template_path = (_template_path,)
         template_path = [os.path.expanduser(path) for path in _template_path]
 
         jenv_opt = jinja_env_options if jinja_env_options else {}
         env = Environment(loader=FileSystemLoader(template_path), **jenv_opt)
         
         sys_info = get_sys_info()
         if sys_info['commit_source'] == 'repository':
             # don't cache (rely on 304) when working from master
             version_hash = ''
         else:
             # reset the cache on server restart
             version_hash = datetime.datetime.now().strftime("%Y%m%d%H%M%S")
 
         settings = dict(
             # basics
             log_function=log_request,
             base_url=base_url,
             default_url=default_url,
             template_path=template_path,
             static_path=ipython_app.static_file_path,
             static_handler_class = FileFindHandler,
             static_url_prefix = url_path_join(base_url,'/static/'),
             static_handler_args = {
                 # don't cache custom.js
                 'no_cache_paths': [url_path_join(base_url, 'static', 'custom')],
             },
             version_hash=version_hash,
             
             # authentication
             cookie_secret=ipython_app.cookie_secret,
             login_url=url_path_join(base_url,'/login'),
             login_handler_class=ipython_app.login_handler_class,
             logout_handler_class=ipython_app.logout_handler_class,
             password=ipython_app.password,
 
             # managers
             kernel_manager=kernel_manager,
             contents_manager=contents_manager,
             cluster_manager=cluster_manager,
             session_manager=session_manager,
             kernel_spec_manager=kernel_spec_manager,
             config_manager=config_manager,
 
             # IPython stuff
             nbextensions_path=ipython_app.nbextensions_path,
             websocket_url=ipython_app.websocket_url,
             mathjax_url=ipython_app.mathjax_url,
             config=ipython_app.config,
             jinja2_env=env,
             terminals_available=False,  # Set later if terminals are available
         )
 
         # allow custom overrides for the tornado web app.
         settings.update(settings_overrides)
         return settings
 
     def init_handlers(self, settings):
         """Load the (URL pattern, handler) tuples for each component."""
         
         # Order matters. The first handler to match the URL will handle the request.
         handlers = []
         handlers.extend(load_handlers('tree.handlers'))
         handlers.extend([(r"/login", settings['login_handler_class'])])
         handlers.extend([(r"/logout", settings['logout_handler_class'])])
         handlers.extend(load_handlers('files.handlers'))
         handlers.extend(load_handlers('notebook.handlers'))
         handlers.extend(load_handlers('nbconvert.handlers'))
         handlers.extend(load_handlers('kernelspecs.handlers'))
         handlers.extend(load_handlers('edit.handlers'))
         handlers.extend(load_handlers('services.config.handlers'))
         handlers.extend(load_handlers('services.kernels.handlers'))
         handlers.extend(load_handlers('services.contents.handlers'))
         handlers.extend(load_handlers('services.clusters.handlers'))
         handlers.extend(load_handlers('services.sessions.handlers'))
         handlers.extend(load_handlers('services.nbconvert.handlers'))
         handlers.extend(load_handlers('services.kernelspecs.handlers'))
         handlers.extend(load_handlers('services.security.handlers'))
         handlers.append(
             (r"/nbextensions/(.*)", FileFindHandler, {
                 'path': settings['nbextensions_path'],
                 'no_cache_paths': ['/'], # don't cache anything in nbextensions
             }),
         )
         # register base handlers last
         handlers.extend(load_handlers('base.handlers'))
         # set the URL that will be redirected from `/`
         handlers.append(
             (r'/?', web.RedirectHandler, {
                 'url' : settings['default_url'],
                 'permanent': False, # want 302, not 301
             })
         )
         # prepend base_url onto the patterns that we match
         new_handlers = []
         for handler in handlers:
             pattern = url_path_join(settings['base_url'], handler[0])
             new_handler = tuple([pattern] + list(handler[1:]))
             new_handlers.append(new_handler)
         # add 404 on the end, which will catch everything that falls through
         new_handlers.append((r'(.*)', Template404))
         return new_handlers
 
 
 class NbserverListApp(BaseIPythonApplication):
     
     description="List currently running notebook servers in this profile."
     
     flags = dict(
         json=({'NbserverListApp': {'json': True}},
               "Produce machine-readable JSON output."),
     )
     
     json = Bool(False, config=True,
           help="If True, each line of output will be a JSON object with the "
                   "details from the server info file.")
 
     def start(self):
         if not self.json:
             print("Currently running servers:")
         for serverinfo in list_running_servers(self.profile):
             if self.json:
                 print(json.dumps(serverinfo))
             else:
                 print(serverinfo['url'], "::", serverinfo['notebook_dir'])
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 
 flags = dict(base_flags)
 flags['no-browser']=(
     {'NotebookApp' : {'open_browser' : False}},
     "Don't open the notebook in a browser after startup."
 )
 flags['pylab']=(
     {'NotebookApp' : {'pylab' : 'warn'}},
     "DISABLED: use %pylab or %matplotlib in the notebook to enable matplotlib."
 )
 flags['no-mathjax']=(
     {'NotebookApp' : {'enable_mathjax' : False}},
     """Disable MathJax
     
     MathJax is the javascript library IPython uses to render math/LaTeX. It is
     very large, so you may want to disable it if you have a slow internet
     connection, or for offline use of the notebook.
     
     When disabled, equations etc. will appear as their untransformed TeX source.
     """
 )
 
 # Add notebook manager flags
 flags.update(boolean_flag('script', 'FileContentsManager.save_script',
                'DEPRECATED, IGNORED',
                'DEPRECATED, IGNORED'))
 
 aliases = dict(base_aliases)
 
 aliases.update({
     'ip': 'NotebookApp.ip',
     'port': 'NotebookApp.port',
     'port-retries': 'NotebookApp.port_retries',
     'transport': 'KernelManager.transport',
     'keyfile': 'NotebookApp.keyfile',
     'certfile': 'NotebookApp.certfile',
     'notebook-dir': 'NotebookApp.notebook_dir',
     'browser': 'NotebookApp.browser',
     'pylab': 'NotebookApp.pylab',
 })
 
 #-----------------------------------------------------------------------------
 # NotebookApp
 #-----------------------------------------------------------------------------
 
 class NotebookApp(BaseIPythonApplication):
 
     name = 'ipython-notebook'
     
     description = """
         The IPython HTML Notebook.
         
         This launches a Tornado based HTML Notebook Server that serves up an
         HTML5/Javascript Notebook client.
     """
     examples = _examples
     aliases = aliases
     flags = flags
     
     classes = [
         KernelManager, ProfileDir, Session, MappingKernelManager,
         ContentsManager, FileContentsManager, NotebookNotary,
         KernelSpecManager,
     ]
     flags = Dict(flags)
     aliases = Dict(aliases)
     
     subcommands = dict(
         list=(NbserverListApp, NbserverListApp.description.splitlines()[0]),
     )
 
     _log_formatter_cls = LogFormatter
 
     def _log_level_default(self):
         return logging.INFO
 
     def _log_datefmt_default(self):
         """Exclude date from default date format"""
         return "%H:%M:%S"
     
     def _log_format_default(self):
         """override default log format to include time"""
         return u"%(color)s[%(levelname)1.1s %(asctime)s.%(msecs).03d %(name)s]%(end_color)s %(message)s"
 
     # create requested profiles by default, if they don't exist:
     auto_create = Bool(True)
 
     # file to be opened in the notebook server
     file_to_run = Unicode('', config=True)
 
     # Network related information
     
     allow_origin = Unicode('', config=True,
         help="""Set the Access-Control-Allow-Origin header
         
         Use '*' to allow any origin to access your server.
         
         Takes precedence over allow_origin_pat.
         """
     )
     
     allow_origin_pat = Unicode('', config=True,
         help="""Use a regular expression for the Access-Control-Allow-Origin header
         
         Requests from an origin matching the expression will get replies with:
         
             Access-Control-Allow-Origin: origin
         
         where `origin` is the origin of the request.
         
         Ignored if allow_origin is set.
         """
     )
     
     allow_credentials = Bool(False, config=True,
         help="Set the Access-Control-Allow-Credentials: true header"
     )
     
     default_url = Unicode('/tree', config=True,
         help="The default URL to redirect to from `/`"
     )
     
     ip = Unicode('localhost', config=True,
         help="The IP address the notebook server will listen on."
     )
     def _ip_default(self):
         """Return localhost if available, 127.0.0.1 otherwise.
         
         On some (horribly broken) systems, localhost cannot be bound.
         """
         s = socket.socket()
         try:
             s.bind(('localhost', 0))
         except socket.error as e:
             self.log.warn("Cannot bind to localhost, using 127.0.0.1 as default ip\n%s", e)
             return '127.0.0.1'
         else:
             s.close()
             return 'localhost'
 
     def _ip_changed(self, name, old, new):
         if new == u'*': self.ip = u''
 
     port = Integer(8888, config=True,
         help="The port the notebook server will listen on."
     )
     port_retries = Integer(50, config=True,
         help="The number of additional ports to try if the specified port is not available."
     )
 
     certfile = Unicode(u'', config=True, 
         help="""The full path to an SSL/TLS certificate file."""
     )
     
     keyfile = Unicode(u'', config=True, 
         help="""The full path to a private key file for usage with SSL/TLS."""
     )
     
     cookie_secret_file = Unicode(config=True,
         help="""The file where the cookie secret is stored."""
     )
     def _cookie_secret_file_default(self):
         if self.profile_dir is None:
             return ''
         return os.path.join(self.profile_dir.security_dir, 'notebook_cookie_secret')
     
     cookie_secret = Bytes(b'', config=True,
         help="""The random bytes used to secure cookies.
         By default this is a new random number every time you start the Notebook.
         Set it to a value in a config file to enable logins to persist across server sessions.
         
         Note: Cookie secrets should be kept private, do not share config files with
         cookie_secret stored in plaintext (you can read the value from a file).
         """
     )
     def _cookie_secret_default(self):
         if os.path.exists(self.cookie_secret_file):
             with io.open(self.cookie_secret_file, 'rb') as f:
                 return f.read()
         else:
             secret = base64.encodestring(os.urandom(1024))
             self._write_cookie_secret_file(secret)
             return secret
     
     def _write_cookie_secret_file(self, secret):
         """write my secret to my secret_file"""
         self.log.info("Writing notebook server cookie secret to %s", self.cookie_secret_file)
         with io.open(self.cookie_secret_file, 'wb') as f:
             f.write(secret)
         try:
             os.chmod(self.cookie_secret_file, 0o600)
         except OSError:
             self.log.warn(
                 "Could not set permissions on %s",
                 self.cookie_secret_file
             )
 
     password = Unicode(u'', config=True,
                       help="""Hashed password to use for web authentication.
 
                       To generate, type in a python/IPython shell:
 
                         from IPython.lib import passwd; passwd()
 
                       The string should be of the form type:salt:hashed-password.
                       """
     )
 
     open_browser = Bool(True, config=True,
                         help="""Whether to open in a browser after starting.
                         The specific browser used is platform dependent and
                         determined by the python standard library `webbrowser`
                         module, unless it is overridden using the --browser
                         (NotebookApp.browser) configuration option.
                         """)
 
     browser = Unicode(u'', config=True,
                       help="""Specify what command to use to invoke a web
                       browser when opening the notebook. If not specified, the
                       default browser will be determined by the `webbrowser`
                       standard library module, which allows setting of the
                       BROWSER environment variable to override it.
                       """)
     
     webapp_settings = Dict(config=True,
         help="DEPRECATED, use tornado_settings"
     )
     def _webapp_settings_changed(self, name, old, new):
         self.log.warn("\n    webapp_settings is deprecated, use tornado_settings.\n")
         self.tornado_settings = new
     
     tornado_settings = Dict(config=True,
             help="Supply overrides for the tornado.web.Application that the "
                  "IPython notebook uses.")
     
     ssl_options = Dict(config=True,
             help="""Supply SSL options for the tornado HTTPServer.
             See the tornado docs for details.""")
     
     jinja_environment_options = Dict(config=True, 
             help="Supply extra arguments that will be passed to Jinja environment.")
     
     enable_mathjax = Bool(True, config=True,
         help="""Whether to enable MathJax for typesetting math/TeX
 
         MathJax is the javascript library IPython uses to render math/LaTeX. It is
         very large, so you may want to disable it if you have a slow internet
         connection, or for offline use of the notebook.
 
         When disabled, equations etc. will appear as their untransformed TeX source.
         """
     )
     def _enable_mathjax_changed(self, name, old, new):
         """set mathjax url to empty if mathjax is disabled"""
         if not new:
             self.mathjax_url = u''
 
     base_url = Unicode('/', config=True,
                                help='''The base URL for the notebook server.
 
                                Leading and trailing slashes can be omitted,
                                and will automatically be added.
                                ''')
     def _base_url_changed(self, name, old, new):
         if not new.startswith('/'):
             self.base_url = '/'+new
         elif not new.endswith('/'):
             self.base_url = new+'/'
     
     base_project_url = Unicode('/', config=True, help="""DEPRECATED use base_url""")
     def _base_project_url_changed(self, name, old, new):
         self.log.warn("base_project_url is deprecated, use base_url")
         self.base_url = new
 
     extra_static_paths = List(Unicode, config=True,
         help="""Extra paths to search for serving static files.
         
         This allows adding javascript/css to be available from the notebook server machine,
         or overriding individual files in the IPython"""
     )
     def _extra_static_paths_default(self):
         return [os.path.join(self.profile_dir.location, 'static')]
     
     @property
     def static_file_path(self):
         """return extra paths + the default location"""
         return self.extra_static_paths + [DEFAULT_STATIC_FILES_PATH]
 
     extra_template_paths = List(Unicode, config=True,
         help="""Extra paths to search for serving jinja templates.
 
         Can be used to override templates from IPython.html.templates."""
     )
     def _extra_template_paths_default(self):
         return []
 
     @property
     def template_file_path(self):
         """return extra paths + the default locations"""
         return self.extra_template_paths + DEFAULT_TEMPLATE_PATH_LIST
 
     extra_nbextensions_path = List(Unicode, config=True,
         help="""extra paths to look for Javascript notebook extensions"""
     )
     
     @property
     def nbextensions_path(self):
         """The path to look for Javascript notebook extensions"""
         return self.extra_nbextensions_path + [os.path.join(get_ipython_dir(), 'nbextensions')] + SYSTEM_NBEXTENSIONS_DIRS
 
     websocket_url = Unicode("", config=True,
         help="""The base URL for websockets,
         if it differs from the HTTP server (hint: it almost certainly doesn't).
         
         Should be in the form of an HTTP origin: ws[s]://hostname[:port]
         """
     )
     mathjax_url = Unicode("", config=True,
         help="""The url for MathJax.js."""
     )
     def _mathjax_url_default(self):
         if not self.enable_mathjax:
             return u''
         static_url_prefix = self.tornado_settings.get("static_url_prefix",
                          url_path_join(self.base_url, "static")
         )
         
         # try local mathjax, either in nbextensions/mathjax or static/mathjax
         for (url_prefix, search_path) in [
             (url_path_join(self.base_url, "nbextensions"), self.nbextensions_path),
             (static_url_prefix, self.static_file_path),
         ]:
             self.log.debug("searching for local mathjax in %s", search_path)
             try:
                 mathjax = filefind(os.path.join('mathjax', 'MathJax.js'), search_path)
             except IOError:
                 continue
             else:
                 url = url_path_join(url_prefix, u"mathjax/MathJax.js")
                 self.log.info("Serving local MathJax from %s at %s", mathjax, url)
                 return url
         
         # no local mathjax, serve from CDN
         url = u"https://cdn.mathjax.org/mathjax/latest/MathJax.js"
         self.log.info("Using MathJax from CDN: %s", url)
         return url
     
     def _mathjax_url_changed(self, name, old, new):
         if new and not self.enable_mathjax:
             # enable_mathjax=False overrides mathjax_url
             self.mathjax_url = u''
         else:
             self.log.info("Using MathJax: %s", new)
 
     contents_manager_class = Type(
         default_value=FileContentsManager,
         klass=ContentsManager,
         config=True,
         help='The notebook manager class to use.'
     )
     kernel_manager_class = Type(
         default_value=MappingKernelManager,
         config=True,
         help='The kernel manager class to use.'
     )
     session_manager_class = Type(
         default_value=SessionManager,
         config=True,
         help='The session manager class to use.'
     )
     cluster_manager_class = Type(
         default_value=ClusterManager,
         config=True,
         help='The cluster manager class to use.'
     )
 
     config_manager_class = Type(
         default_value=ConfigManager,
         config = True,
         help='The config manager class to use'
     )
 
-    kernel_spec_manager = Instance(KernelSpecManager)
+    kernel_spec_manager = Instance(KernelSpecManager, allow_none=True)
 
     kernel_spec_manager_class = Type(
         default_value=KernelSpecManager,
         config=True,
         help="""
         The kernel spec manager class to use. Should be a subclass
         of `IPython.kernel.kernelspec.KernelSpecManager`.
 
         The Api of KernelSpecManager is provisional and might change
         without warning between this version of IPython and the next stable one.
         """
     )
 
     login_handler_class = Type(
         default_value=LoginHandler,
         klass=web.RequestHandler,
         config=True,
         help='The login handler class to use.',
     )
 
     logout_handler_class = Type(
         default_value=LogoutHandler,
         klass=web.RequestHandler,
         config=True,
         help='The logout handler class to use.',
     )
 
     trust_xheaders = Bool(False, config=True,
         help=("Whether to trust or not X-Scheme/X-Forwarded-Proto and X-Real-Ip/X-Forwarded-For headers"
               "sent by the upstream reverse proxy. Necessary if the proxy handles SSL")
     )
 
     info_file = Unicode()
 
     def _info_file_default(self):
         info_file = "nbserver-%s.json"%os.getpid()
         return os.path.join(self.profile_dir.security_dir, info_file)
     
     pylab = Unicode('disabled', config=True,
         help="""
         DISABLED: use %pylab or %matplotlib in the notebook to enable matplotlib.
         """
     )
     def _pylab_changed(self, name, old, new):
         """when --pylab is specified, display a warning and exit"""
         if new != 'warn':
             backend = ' %s' % new
         else:
             backend = ''
         self.log.error("Support for specifying --pylab on the command line has been removed.")
         self.log.error(
             "Please use `%pylab{0}` or `%matplotlib{0}` in the notebook itself.".format(backend)
         )
         self.exit(1)
 
     notebook_dir = Unicode(config=True,
         help="The directory to use for notebooks and kernels."
     )
 
     def _notebook_dir_default(self):
         if self.file_to_run:
             return os.path.dirname(os.path.abspath(self.file_to_run))
         else:
             return py3compat.getcwd()
 
     def _notebook_dir_changed(self, name, old, new):
         """Do a bit of validation of the notebook dir."""
         if not os.path.isabs(new):
             # If we receive a non-absolute path, make it absolute.
             self.notebook_dir = os.path.abspath(new)
             return
         if not os.path.isdir(new):
             raise TraitError("No such notebook dir: %r" % new)
         
         # setting App.notebook_dir implies setting notebook and kernel dirs as well
         self.config.FileContentsManager.root_dir = new
         self.config.MappingKernelManager.root_dir = new
 
     server_extensions = List(Unicode(), config=True,
         help=("Python modules to load as notebook server extensions. "
               "This is an experimental API, and may change in future releases.")
     )
 
     reraise_server_extension_failures = Bool(
         False,
         config=True,
         help="Reraise exceptions encountered loading server extensions?",
     )
 
     def parse_command_line(self, argv=None):
         super(NotebookApp, self).parse_command_line(argv)
         
         if self.extra_args:
             arg0 = self.extra_args[0]
             f = os.path.abspath(arg0)
             self.argv.remove(arg0)
             if not os.path.exists(f):
                 self.log.critical("No such file or directory: %s", f)
                 self.exit(1)
             
             # Use config here, to ensure that it takes higher priority than
             # anything that comes from the profile.
             c = Config()
             if os.path.isdir(f):
                 c.NotebookApp.notebook_dir = f
             elif os.path.isfile(f):
                 c.NotebookApp.file_to_run = f
             self.update_config(c)
 
     def init_configurables(self):
         self.kernel_spec_manager = self.kernel_spec_manager_class(
             parent=self,
             ipython_dir=self.ipython_dir,
         )
         self.kernel_manager = self.kernel_manager_class(
             parent=self,
             log=self.log,
             connection_dir=self.profile_dir.security_dir,
         )
         self.contents_manager = self.contents_manager_class(
             parent=self,
             log=self.log,
         )
         self.session_manager = self.session_manager_class(
             parent=self,
             log=self.log,
             kernel_manager=self.kernel_manager,
             contents_manager=self.contents_manager,
         )
         self.cluster_manager = self.cluster_manager_class(
             parent=self,
             log=self.log,
         )
 
         self.config_manager = self.config_manager_class(
             parent=self,
             log=self.log,
             profile_dir=self.profile_dir.location,
         )
 
     def init_logging(self):
         # This prevents double log messages because tornado use a root logger that
         # self.log is a child of. The logging module dipatches log messages to a log
         # and all of its ancenstors until propagate is set to False.
         self.log.propagate = False
         
         for log in app_log, access_log, gen_log:
             # consistent log output name (NotebookApp instead of tornado.access, etc.)
             log.name = self.log.name
         # hook up tornado 3's loggers to our app handlers
         logger = logging.getLogger('tornado')
         logger.propagate = True
         logger.parent = self.log
         logger.setLevel(self.log.level)
     
     def init_webapp(self):
         """initialize tornado webapp and httpserver"""
         self.tornado_settings['allow_origin'] = self.allow_origin
         if self.allow_origin_pat:
             self.tornado_settings['allow_origin_pat'] = re.compile(self.allow_origin_pat)
         self.tornado_settings['allow_credentials'] = self.allow_credentials
         # ensure default_url starts with base_url
         if not self.default_url.startswith(self.base_url):
             self.default_url = url_path_join(self.base_url, self.default_url)
         
         self.web_app = NotebookWebApplication(
             self, self.kernel_manager, self.contents_manager,
             self.cluster_manager, self.session_manager, self.kernel_spec_manager,
             self.config_manager,
             self.log, self.base_url, self.default_url, self.tornado_settings,
             self.jinja_environment_options
         )
         ssl_options = self.ssl_options
         if self.certfile:
             ssl_options['certfile'] = self.certfile
         if self.keyfile:
             ssl_options['keyfile'] = self.keyfile
         if not ssl_options:
             # None indicates no SSL config
             ssl_options = None
         self.login_handler_class.validate_security(self, ssl_options=ssl_options)
         self.http_server = httpserver.HTTPServer(self.web_app, ssl_options=ssl_options,
                                                  xheaders=self.trust_xheaders)
 
         success = None
         for port in random_ports(self.port, self.port_retries+1):
             try:
                 self.http_server.listen(port, self.ip)
             except socket.error as e:
                 if e.errno == errno.EADDRINUSE:
                     self.log.info('The port %i is already in use, trying another random port.' % port)
                     continue
                 elif e.errno in (errno.EACCES, getattr(errno, 'WSAEACCES', errno.EACCES)):
                     self.log.warn("Permission to listen on port %i denied" % port)
                     continue
                 else:
                     raise
             else:
                 self.port = port
                 success = True
                 break
         if not success:
             self.log.critical('ERROR: the notebook server could not be started because '
                               'no available port could be found.')
             self.exit(1)
     
     @property
     def display_url(self):
         ip = self.ip if self.ip else '[all ip addresses on your system]'
         return self._url(ip)
 
     @property
     def connection_url(self):
         ip = self.ip if self.ip else 'localhost'
         return self._url(ip)
 
     def _url(self, ip):
         proto = 'https' if self.certfile else 'http'
         return "%s://%s:%i%s" % (proto, ip, self.port, self.base_url)
 
     def init_terminals(self):
         try:
             from .terminal import initialize
             initialize(self.web_app)
             self.web_app.settings['terminals_available'] = True
         except ImportError as e:
             log = self.log.debug if sys.platform == 'win32' else self.log.warn
             log("Terminals not available (error was %s)", e)
 
     def init_signal(self):
         if not sys.platform.startswith('win'):
             signal.signal(signal.SIGINT, self._handle_sigint)
         signal.signal(signal.SIGTERM, self._signal_stop)
         if hasattr(signal, 'SIGUSR1'):
             # Windows doesn't support SIGUSR1
             signal.signal(signal.SIGUSR1, self._signal_info)
         if hasattr(signal, 'SIGINFO'):
             # only on BSD-based systems
             signal.signal(signal.SIGINFO, self._signal_info)
     
     def _handle_sigint(self, sig, frame):
         """SIGINT handler spawns confirmation dialog"""
         # register more forceful signal handler for ^C^C case
         signal.signal(signal.SIGINT, self._signal_stop)
         # request confirmation dialog in bg thread, to avoid
         # blocking the App
         thread = threading.Thread(target=self._confirm_exit)
         thread.daemon = True
         thread.start()
     
     def _restore_sigint_handler(self):
         """callback for restoring original SIGINT handler"""
         signal.signal(signal.SIGINT, self._handle_sigint)
     
     def _confirm_exit(self):
         """confirm shutdown on ^C
         
         A second ^C, or answering 'y' within 5s will cause shutdown,
         otherwise original SIGINT handler will be restored.
         
         This doesn't work on Windows.
         """
         info = self.log.info
         info('interrupted')
         print(self.notebook_info())
         sys.stdout.write("Shutdown this notebook server (y/[n])? ")
         sys.stdout.flush()
         r,w,x = select.select([sys.stdin], [], [], 5)
         if r:
             line = sys.stdin.readline()
             if line.lower().startswith('y') and 'n' not in line.lower():
                 self.log.critical("Shutdown confirmed")
                 ioloop.IOLoop.current().stop()
                 return
         else:
             print("No answer for 5s:", end=' ')
         print("resuming operation...")
         # no answer, or answer is no:
         # set it back to original SIGINT handler
         # use IOLoop.add_callback because signal.signal must be called
         # from main thread
         ioloop.IOLoop.current().add_callback(self._restore_sigint_handler)
     
     def _signal_stop(self, sig, frame):
         self.log.critical("received signal %s, stopping", sig)
         ioloop.IOLoop.current().stop()
 
     def _signal_info(self, sig, frame):
         print(self.notebook_info())
     
     def init_components(self):
         """Check the components submodule, and warn if it's unclean"""
         status = submodule.check_submodule_status()
         if status == 'missing':
             self.log.warn("components submodule missing, running `git submodule update`")
             submodule.update_submodules(submodule.ipython_parent())
         elif status == 'unclean':
             self.log.warn("components submodule unclean, you may see 404s on static/components")
             self.log.warn("run `setup.py submodule` or `git submodule update` to update")
 
     def init_server_extensions(self):
         """Load any extensions specified by config.
 
         Import the module, then call the load_jupyter_server_extension function,
         if one exists.
         
         The extension API is experimental, and may change in future releases.
         """
         for modulename in self.server_extensions:
             try:
                 mod = importlib.import_module(modulename)
                 func = getattr(mod, 'load_jupyter_server_extension', None)
                 if func is not None:
                     func(self)
             except Exception:
                 if self.reraise_server_extension_failures:
                     raise
                 self.log.warn("Error loading server extension %s", modulename,
                               exc_info=True)
     
     @catch_config_error
     def initialize(self, argv=None):
         super(NotebookApp, self).initialize(argv)
         self.init_logging()
         self.init_configurables()
         self.init_components()
         self.init_webapp()
         self.init_terminals()
         self.init_signal()
         self.init_server_extensions()
 
     def cleanup_kernels(self):
         """Shutdown all kernels.
         
         The kernels will shutdown themselves when this process no longer exists,
         but explicit shutdown allows the KernelManagers to cleanup the connection files.
         """
         self.log.info('Shutting down kernels')
         self.kernel_manager.shutdown_all()
 
     def notebook_info(self):
         "Return the current working directory and the server url information"
         info = self.contents_manager.info_string() + "\n"
         info += "%d active kernels \n" % len(self.kernel_manager._kernels)
         return info + "The IPython Notebook is running at: %s" % self.display_url
 
     def server_info(self):
         """Return a JSONable dict of information about this server."""
         return {'url': self.connection_url,
                 'hostname': self.ip if self.ip else 'localhost',
                 'port': self.port,
                 'secure': bool(self.certfile),
                 'base_url': self.base_url,
                 'notebook_dir': os.path.abspath(self.notebook_dir),
                 'pid': os.getpid()
                }
 
     def write_server_info_file(self):
         """Write the result of server_info() to the JSON file info_file."""
         with open(self.info_file, 'w') as f:
             json.dump(self.server_info(), f, indent=2)
 
     def remove_server_info_file(self):
         """Remove the nbserver-<pid>.json file created for this server.
         
         Ignores the error raised when the file has already been removed.
         """
         try:
             os.unlink(self.info_file)
         except OSError as e:
             if e.errno != errno.ENOENT:
                 raise
 
     def start(self):
         """ Start the IPython Notebook server app, after initialization
         
         This method takes no arguments so all configuration and initialization
         must be done prior to calling this method."""
         if self.subapp is not None:
             return self.subapp.start()
 
         info = self.log.info
         for line in self.notebook_info().split("\n"):
             info(line)
         info("Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).")
 
         self.write_server_info_file()
 
         if self.open_browser or self.file_to_run:
             try:
                 browser = webbrowser.get(self.browser or None)
             except webbrowser.Error as e:
                 self.log.warn('No web browser found: %s.' % e)
                 browser = None
             
             if self.file_to_run:
                 if not os.path.exists(self.file_to_run):
                     self.log.critical("%s does not exist" % self.file_to_run)
                     self.exit(1)
 
                 relpath = os.path.relpath(self.file_to_run, self.notebook_dir)
                 uri = url_path_join('notebooks', *relpath.split(os.sep))
             else:
                 uri = 'tree'
             if browser:
                 b = lambda : browser.open(url_path_join(self.connection_url, uri),
                                           new=2)
                 threading.Thread(target=b).start()
         
         self.io_loop = ioloop.IOLoop.current()
         if sys.platform.startswith('win'):
             # add no-op to wake every 5s
             # to handle signals that may be ignored by the inner loop
             pc = ioloop.PeriodicCallback(lambda : None, 5000)
             pc.start()
         try:
             self.io_loop.start()
         except KeyboardInterrupt:
             info("Interrupted...")
         finally:
             self.cleanup_kernels()
             self.remove_server_info_file()
     
     def stop(self):
         def _stop():
             self.http_server.stop()
             self.io_loop.stop()
         self.io_loop.add_callback(_stop)
 
 
 def list_running_servers(profile='default'):
     """Iterate over the server info files of running notebook servers.
     
     Given a profile name, find nbserver-* files in the security directory of
     that profile, and yield dicts of their information, each one pertaining to
     a currently running notebook server instance.
     """
     pd = ProfileDir.find_profile_dir_by_name(get_ipython_dir(), name=profile)
     for file in os.listdir(pd.security_dir):
         if file.startswith('nbserver-'):
             with io.open(os.path.join(pd.security_dir, file), encoding='utf-8') as f:
                 info = json.load(f)
 
             # Simple check whether that process is really still running
             # Also remove leftover files from IPython 2.x without a pid field
             if ('pid' in info) and check_pid(info['pid']):
                 yield info
             else:
                 # If the process has died, try to delete its info file
                 try:
                     os.unlink(file)
                 except OSError:
                     pass  # TODO: This should warn or log or something
 #-----------------------------------------------------------------------------
 # Main entry point
 #-----------------------------------------------------------------------------
 
 launch_new_instance = NotebookApp.launch_instance
 

IPython/html/services/clusters/clustermanager.py

@@ -1,162 +1,162 b''
 """Manage IPython.parallel clusters in the notebook."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from tornado import web
 
 from IPython.config.configurable import LoggingConfigurable
 from IPython.utils.traitlets import Dict, Instance, Float
 from IPython.core.profileapp import list_profiles_in
 from IPython.core.profiledir import ProfileDir
 from IPython.utils import py3compat
 from IPython.utils.path import get_ipython_dir
 
 
 class ClusterManager(LoggingConfigurable):
 
     profiles = Dict()
 
     delay = Float(1., config=True,
         help="delay (in s) between starting the controller and the engines")
 
-    loop = Instance('zmq.eventloop.ioloop.IOLoop')
+    loop = Instance('zmq.eventloop.ioloop.IOLoop', allow_none=True)
     def _loop_default(self):
         from zmq.eventloop.ioloop import IOLoop
         return IOLoop.instance()
 
     def build_launchers(self, profile_dir):
         from IPython.parallel.apps.ipclusterapp import IPClusterStart
         
         class DummyIPClusterStart(IPClusterStart):
             """Dummy subclass to skip init steps that conflict with global app.
     
             Instantiating and initializing this class should result in fully configured
             launchers, but no other side effects or state.
             """
 
             def init_signal(self):
                 pass
             def reinit_logging(self):
                 pass
         
         starter = DummyIPClusterStart(log=self.log)
         starter.initialize(['--profile-dir', profile_dir])
         cl = starter.controller_launcher
         esl = starter.engine_launcher
         n = starter.n
         return cl, esl, n
 
     def get_profile_dir(self, name, path):
         p = ProfileDir.find_profile_dir_by_name(path,name=name)
         return p.location
 
     def update_profiles(self):
         """List all profiles in the ipython_dir and cwd.
         """
         
         stale = set(self.profiles)
         for path in [get_ipython_dir(), py3compat.getcwd()]:
             for profile in list_profiles_in(path):
                 if profile in stale:
                     stale.remove(profile)
                 pd = self.get_profile_dir(profile, path)
                 if profile not in self.profiles:
                     self.log.debug("Adding cluster profile '%s'", profile)
                     self.profiles[profile] = {
                         'profile': profile,
                         'profile_dir': pd,
                         'status': 'stopped'
                     }
         for profile in stale:
             # remove profiles that no longer exist
             self.log.debug("Profile '%s' no longer exists", profile)
             self.profiles.pop(stale)
 
     def list_profiles(self):
         self.update_profiles()
         # sorted list, but ensure that 'default' always comes first
         default_first = lambda name: name if name != 'default' else ''
         result = [self.profile_info(p) for p in sorted(self.profiles, key=default_first)]
         return result
 
     def check_profile(self, profile):
         if profile not in self.profiles:
             raise web.HTTPError(404, u'profile not found')
 
     def profile_info(self, profile):
         self.check_profile(profile)
         result = {}
         data = self.profiles.get(profile)
         result['profile'] = profile
         result['profile_dir'] = data['profile_dir']
         result['status'] = data['status']
         if 'n' in data:
             result['n'] = data['n']
         return result
 
     def start_cluster(self, profile, n=None):
         """Start a cluster for a given profile."""
         self.check_profile(profile)
         data = self.profiles[profile]
         if data['status'] == 'running':
             raise web.HTTPError(409, u'cluster already running')
         cl, esl, default_n = self.build_launchers(data['profile_dir'])
         n = n if n is not None else default_n
         def clean_data():
             data.pop('controller_launcher',None)
             data.pop('engine_set_launcher',None)
             data.pop('n',None)
             data['status'] = 'stopped'
         def engines_stopped(r):
             self.log.debug('Engines stopped')
             if cl.running:
                 cl.stop()
             clean_data()
         esl.on_stop(engines_stopped)
         def controller_stopped(r):
             self.log.debug('Controller stopped')
             if esl.running:
                 esl.stop()
             clean_data()
         cl.on_stop(controller_stopped)
         loop = self.loop
         
         def start():
             """start the controller, then the engines after a delay"""
             cl.start()
             loop.add_timeout(self.loop.time() + self.delay, lambda : esl.start(n))
         self.loop.add_callback(start)
 
         self.log.debug('Cluster started')
         data['controller_launcher'] = cl
         data['engine_set_launcher'] = esl
         data['n'] = n
         data['status'] = 'running'
         return self.profile_info(profile)
 
     def stop_cluster(self, profile):
         """Stop a cluster for a given profile."""
         self.check_profile(profile)
         data = self.profiles[profile]
         if data['status'] == 'stopped':
             raise web.HTTPError(409, u'cluster not running')
         data = self.profiles[profile]
         cl = data['controller_launcher']
         esl = data['engine_set_launcher']
         if cl.running:
             cl.stop()
         if esl.running:
             esl.stop()
         # Return a temp info dict, the real one is updated in the on_stop
         # logic above.
         result = {
             'profile': data['profile'],
             'profile_dir': data['profile_dir'],
             'status': 'stopped'
         }
         return result
 
     def stop_all_clusters(self):
         for p in self.profiles.keys():
             self.stop_cluster(p)

IPython/html/widgets/widget.py

@@ -1,497 +1,497 b''
 """Base Widget class.  Allows user to create widgets in the back-end that render
 in the IPython notebook front-end.
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2013, 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
 #-----------------------------------------------------------------------------
 from contextlib import contextmanager
 import collections
 
 from IPython.core.getipython import get_ipython
 from IPython.kernel.comm import Comm
 from IPython.config import LoggingConfigurable
 from IPython.utils.importstring import import_item
 from IPython.utils.traitlets import Unicode, Dict, Instance, Bool, List, \
     CaselessStrEnum, Tuple, CUnicode, Int, Set
 from IPython.utils.py3compat import string_types
 from .trait_types import Color
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class CallbackDispatcher(LoggingConfigurable):
     """A structure for registering and running callbacks"""
     callbacks = List()
     
     def __call__(self, *args, **kwargs):
         """Call all of the registered callbacks."""
         value = None
         for callback in self.callbacks:
             try:
                 local_value = callback(*args, **kwargs)
             except Exception as e:
                 ip = get_ipython()
                 if ip is None:
                     self.log.warn("Exception in callback %s: %s", callback, e, exc_info=True)
                 else:
                     ip.showtraceback()
             else:
                 value = local_value if local_value is not None else value
         return value
 
     def register_callback(self, callback, remove=False):
         """(Un)Register a callback
 
         Parameters
         ----------
         callback: method handle
             Method to be registered or unregistered.
         remove=False: bool
             Whether to unregister the callback."""
         
         # (Un)Register the callback.
         if remove and callback in self.callbacks:
             self.callbacks.remove(callback)
         elif not remove and callback not in self.callbacks:
             self.callbacks.append(callback)
 
 def _show_traceback(method):
     """decorator for showing tracebacks in IPython"""
     def m(self, *args, **kwargs):
         try:
             return(method(self, *args, **kwargs))
         except Exception as e:
             ip = get_ipython()
             if ip is None:
                 self.log.warn("Exception in widget method %s: %s", method, e, exc_info=True)
             else:
                 ip.showtraceback()
     return m
 
 
 def register(key=None):
     """Returns a decorator registering a widget class in the widget registry. 
     If no key is provided, the class name is used as a key. A key is
     provided for each core IPython widget so that the frontend can use
     this key regardless of the language of the kernel"""
     def wrap(widget):
         l = key if key is not None else widget.__module__ + widget.__name__
         Widget.widget_types[l] = widget
         return widget
     return wrap
 
 
 class Widget(LoggingConfigurable):
     #-------------------------------------------------------------------------
     # Class attributes
     #-------------------------------------------------------------------------
     _widget_construction_callback = None
     widgets = {}
     widget_types = {}
 
     @staticmethod
     def on_widget_constructed(callback):
         """Registers a callback to be called when a widget is constructed.
 
         The callback must have the following signature:
         callback(widget)"""
         Widget._widget_construction_callback = callback
 
     @staticmethod
     def _call_widget_constructed(widget):
         """Static method, called when a widget is constructed."""
         if Widget._widget_construction_callback is not None and callable(Widget._widget_construction_callback):
             Widget._widget_construction_callback(widget)
 
     @staticmethod
     def handle_comm_opened(comm, msg):
         """Static method, called when a widget is constructed."""
         widget_class = import_item(msg['content']['data']['widget_class'])
         widget = widget_class(comm=comm)
 
 
     #-------------------------------------------------------------------------
     # Traits
     #-------------------------------------------------------------------------
     _model_module = Unicode(None, allow_none=True, help="""A requirejs module name
         in which to find _model_name. If empty, look in the global registry.""")
     _model_name = Unicode('WidgetModel', help="""Name of the backbone model 
         registered in the front-end to create and sync this widget with.""")
     _view_module = Unicode(help="""A requirejs module in which to find _view_name.
         If empty, look in the global registry.""", sync=True)
     _view_name = Unicode(None, allow_none=True, help="""Default view registered in the front-end
         to use to represent the widget.""", sync=True)
-    comm = Instance('IPython.kernel.comm.Comm')
+    comm = Instance('IPython.kernel.comm.Comm', allow_none=True)
     
     msg_throttle = Int(3, sync=True, help="""Maximum number of msgs the 
         front-end can send before receiving an idle msg from the back-end.""")
     
     version = Int(0, sync=True, help="""Widget's version""")
     keys = List()
     def _keys_default(self):
         return [name for name in self.traits(sync=True)]
     
     _property_lock = Tuple((None, None))
     _send_state_lock = Int(0)
     _states_to_send = Set()
     _display_callbacks = Instance(CallbackDispatcher, ())
     _msg_callbacks = Instance(CallbackDispatcher, ())
     
     #-------------------------------------------------------------------------
     # (Con/de)structor
     #-------------------------------------------------------------------------
     def __init__(self, **kwargs):
         """Public constructor"""
         self._model_id = kwargs.pop('model_id', None)
         super(Widget, self).__init__(**kwargs)
 
         Widget._call_widget_constructed(self)
         self.open()
 
     def __del__(self):
         """Object disposal"""
         self.close()
 
     #-------------------------------------------------------------------------
     # Properties
     #-------------------------------------------------------------------------
 
     def open(self):
         """Open a comm to the frontend if one isn't already open."""
         if self.comm is None:
             args = dict(target_name='ipython.widget',
                         data={'model_name': self._model_name,
                               'model_module': self._model_module})
             if self._model_id is not None:
                 args['comm_id'] = self._model_id
             self.comm = Comm(**args)
 
     def _comm_changed(self, name, new):
         """Called when the comm is changed."""
         if new is None:
             return
         self._model_id = self.model_id
         
         self.comm.on_msg(self._handle_msg)
         Widget.widgets[self.model_id] = self
         
         # first update
         self.send_state()
 
     @property
     def model_id(self):
         """Gets the model id of this widget.
 
         If a Comm doesn't exist yet, a Comm will be created automagically."""
         return self.comm.comm_id
 
     #-------------------------------------------------------------------------
     # Methods
     #-------------------------------------------------------------------------
 
     def close(self):
         """Close method.
 
         Closes the underlying comm.
         When the comm is closed, all of the widget views are automatically
         removed from the front-end."""
         if self.comm is not None:
             Widget.widgets.pop(self.model_id, None)
             self.comm.close()
             self.comm = None
     
     def send_state(self, key=None):
         """Sends the widget state, or a piece of it, to the front-end.
 
         Parameters
         ----------
         key : unicode, or iterable (optional)
             A single property's name or iterable of property names to sync with the front-end.
         """
         self._send({
             "method" : "update",
             "state"  : self.get_state(key=key)
         })
 
     def get_state(self, key=None):
         """Gets the widget state, or a piece of it.
 
         Parameters
         ----------
         key : unicode or iterable (optional)
             A single property's name or iterable of property names to get.
         """
         if key is None:
             keys = self.keys
         elif isinstance(key, string_types):
             keys = [key]
         elif isinstance(key, collections.Iterable):
             keys = key
         else:
             raise ValueError("key must be a string, an iterable of keys, or None")
         state = {}
         for k in keys:
             f = self.trait_metadata(k, 'to_json', self._trait_to_json)
             value = getattr(self, k)
             state[k] = f(value)
         return state
 
     def set_state(self, sync_data):
         """Called when a state is received from the front-end."""
         for name in self.keys:
             if name in sync_data:
                 json_value = sync_data[name]
                 from_json = self.trait_metadata(name, 'from_json', self._trait_from_json)
                 with self._lock_property(name, json_value):
                     setattr(self, name, from_json(json_value))
     
     def send(self, content):
         """Sends a custom msg to the widget model in the front-end.
 
         Parameters
         ----------
         content : dict
             Content of the message to send.
         """
         self._send({"method": "custom", "content": content})
 
     def on_msg(self, callback, remove=False):
         """(Un)Register a custom msg receive callback.
 
         Parameters
         ----------
         callback: callable
             callback will be passed two arguments when a message arrives::
             
                 callback(widget, content)
             
         remove: bool
             True if the callback should be unregistered."""
         self._msg_callbacks.register_callback(callback, remove=remove)
 
     def on_displayed(self, callback, remove=False):
         """(Un)Register a widget displayed callback.
 
         Parameters
         ----------
         callback: method handler
             Must have a signature of::
             
                 callback(widget, **kwargs)
             
             kwargs from display are passed through without modification.
         remove: bool
             True if the callback should be unregistered."""
         self._display_callbacks.register_callback(callback, remove=remove)
 
     def add_trait(self, traitname, trait):
         """Dynamically add a trait attribute to the Widget."""
         super(Widget, self).add_trait(traitname, trait)
         if trait.get_metadata('sync'):
              self.keys.append(traitname)
              self.send_state(traitname)
 
     #-------------------------------------------------------------------------
     # Support methods
     #-------------------------------------------------------------------------
     @contextmanager
     def _lock_property(self, key, value):
         """Lock a property-value pair.
 
         The value should be the JSON state of the property.
 
         NOTE: This, in addition to the single lock for all state changes, is 
         flawed.  In the future we may want to look into buffering state changes 
         back to the front-end."""
         self._property_lock = (key, value)
         try:
             yield
         finally:
             self._property_lock = (None, None)
 
     @contextmanager
     def hold_sync(self):
         """Hold syncing any state until the context manager is released"""
         # We increment a value so that this can be nested.  Syncing will happen when
         # all levels have been released.
         self._send_state_lock += 1
         try:
             yield
         finally:
             self._send_state_lock -=1
             if self._send_state_lock == 0:
                 self.send_state(self._states_to_send)
                 self._states_to_send.clear()
 
     def _should_send_property(self, key, value):
         """Check the property lock (property_lock)"""
         to_json = self.trait_metadata(key, 'to_json', self._trait_to_json)
         if (key == self._property_lock[0]
             and to_json(value) == self._property_lock[1]):
             return False
         elif self._send_state_lock > 0:
             self._states_to_send.add(key)
             return False
         else:
             return True
     
     # Event handlers
     @_show_traceback
     def _handle_msg(self, msg):
         """Called when a msg is received from the front-end"""
         data = msg['content']['data']
         method = data['method']
 
         # Handle backbone sync methods CREATE, PATCH, and UPDATE all in one.
         if method == 'backbone':
             if 'sync_data' in data:
                 sync_data = data['sync_data']
                 self.set_state(sync_data) # handles all methods
 
         # Handle a state request.
         elif method == 'request_state':
             self.send_state()
 
         # Handle a custom msg from the front-end.
         elif method == 'custom':
             if 'content' in data:
                 self._handle_custom_msg(data['content'])
 
         # Catch remainder.
         else:
             self.log.error('Unknown front-end to back-end widget msg with method "%s"' % method)
 
     def _handle_custom_msg(self, content):
         """Called when a custom msg is received."""
         self._msg_callbacks(self, content)
 
     def _notify_trait(self, name, old_value, new_value):
         """Called when a property has been changed."""
         # Trigger default traitlet callback machinery.  This allows any user
         # registered validation to be processed prior to allowing the widget
         # machinery to handle the state.
         LoggingConfigurable._notify_trait(self, name, old_value, new_value)
 
         # Send the state after the user registered callbacks for trait changes
         # have all fired (allows for user to validate values).
         if self.comm is not None and name in self.keys:
             # Make sure this isn't information that the front-end just sent us.
             if self._should_send_property(name, new_value):
                 # Send new state to front-end
                 self.send_state(key=name)
 
     def _handle_displayed(self, **kwargs):
         """Called when a view has been displayed for this widget instance"""
         self._display_callbacks(self, **kwargs)
 
     def _trait_to_json(self, x):
         """Convert a trait value to json
 
         Traverse lists/tuples and dicts and serialize their values as well.
         Replace any widgets with their model_id
         """
         if isinstance(x, dict):
             return {k: self._trait_to_json(v) for k, v in x.items()}
         elif isinstance(x, (list, tuple)):
             return [self._trait_to_json(v) for v in x]
         elif isinstance(x, Widget):
             return "IPY_MODEL_" + x.model_id
         else:
             return x # Value must be JSON-able
 
     def _trait_from_json(self, x):
         """Convert json values to objects
 
         Replace any strings representing valid model id values to Widget references.
         """
         if isinstance(x, dict):
             return {k: self._trait_from_json(v) for k, v in x.items()}
         elif isinstance(x, (list, tuple)):
             return [self._trait_from_json(v) for v in x]
         elif isinstance(x, string_types) and x.startswith('IPY_MODEL_') and x[10:] in Widget.widgets:
             # we want to support having child widgets at any level in a hierarchy
             # trusting that a widget UUID will not appear out in the wild
             return Widget.widgets[x[10:]]
         else:
             return x
 
     def _ipython_display_(self, **kwargs):
         """Called when `IPython.display.display` is called on the widget."""
         # Show view.
         if self._view_name is not None:
             self._send({"method": "display"})
             self._handle_displayed(**kwargs)
 
     def _send(self, msg):
         """Sends a message to the model in the front-end."""
         self.comm.send(msg)
 
 
 class DOMWidget(Widget):
     visible = Bool(True, allow_none=True, help="Whether the widget is visible.  False collapses the empty space, while None preserves the empty space.", sync=True)
     _css = Tuple(sync=True, help="CSS property list: (selector, key, value)")
     _dom_classes = Tuple(sync=True, help="DOM classes applied to widget.$el.")
     
     width = CUnicode(sync=True)
     height = CUnicode(sync=True)
     # A default padding of 2.5 px makes the widgets look nice when displayed inline.
     padding = CUnicode(sync=True)
     margin = CUnicode(sync=True)
 
     color = Color(None, allow_none=True, sync=True)
     background_color = Color(None, allow_none=True, sync=True)
     border_color = Color(None, allow_none=True, sync=True)
 
     border_width = CUnicode(sync=True)
     border_radius = CUnicode(sync=True)
     border_style = CaselessStrEnum(values=[ # http://www.w3schools.com/cssref/pr_border-style.asp
         'none', 
         'hidden', 
         'dotted', 
         'dashed', 
         'solid', 
         'double', 
         'groove', 
         'ridge', 
         'inset', 
         'outset', 
         'initial', 
         'inherit', ''],
         default_value='', sync=True)
 
     font_style = CaselessStrEnum(values=[ # http://www.w3schools.com/cssref/pr_font_font-style.asp
         'normal', 
         'italic', 
         'oblique', 
         'initial', 
         'inherit', ''], 
         default_value='', sync=True)
     font_weight = CaselessStrEnum(values=[ # http://www.w3schools.com/cssref/pr_font_weight.asp
         'normal', 
         'bold', 
         'bolder', 
         'lighter',
         'initial', 
         'inherit', ''] + list(map(str, range(100,1000,100))),
         default_value='', sync=True)
     font_size = CUnicode(sync=True)
     font_family = Unicode(sync=True)
 
     def __init__(self, *pargs, **kwargs):
         super(DOMWidget, self).__init__(*pargs, **kwargs)
 
         def _validate_border(name, old, new):
             if new is not None and new != '':
                 if name != 'border_width' and not self.border_width:
                     self.border_width = 1
                 if name != 'border_style' and self.border_style == '':
                     self.border_style = 'solid'
         self.on_trait_change(_validate_border, ['border_width', 'border_style', 'border_color'])

IPython/kernel/inprocess/client.py

@@ -1,156 +1,157 b''
 """A client for in-process kernels."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2012  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
 #-----------------------------------------------------------------------------
 
 # IPython imports
 from IPython.kernel.inprocess.socket import DummySocket
 from IPython.utils.traitlets import Type, Instance
 from IPython.kernel.clientabc import KernelClientABC
 from IPython.kernel.client import KernelClient
 
 # Local imports
 from .channels import (
     InProcessChannel,
     InProcessHBChannel,
 
 )
 
 #-----------------------------------------------------------------------------
 # Main kernel Client class
 #-----------------------------------------------------------------------------
 
 class InProcessKernelClient(KernelClient):
     """A client for an in-process kernel.
 
     This class implements the interface of
     `IPython.kernel.clientabc.KernelClientABC` and allows
     (asynchronous) frontends to be used seamlessly with an in-process kernel.
 
     See `IPython.kernel.client.KernelClient` for docstrings.
     """
 
     # The classes to use for the various channels.
     shell_channel_class = Type(InProcessChannel)
     iopub_channel_class = Type(InProcessChannel)
     stdin_channel_class = Type(InProcessChannel)
     hb_channel_class = Type(InProcessHBChannel)
 
-    kernel = Instance('IPython.kernel.inprocess.ipkernel.InProcessKernel')
+    kernel = Instance('IPython.kernel.inprocess.ipkernel.InProcessKernel', 
+                      allow_none=True)
 
     #--------------------------------------------------------------------------
     # Channel management methods
     #--------------------------------------------------------------------------
 
     def start_channels(self, *args, **kwargs):
         super(InProcessKernelClient, self).start_channels(self)
         self.kernel.frontends.append(self)
 
     @property
     def shell_channel(self):
         if self._shell_channel is None:
             self._shell_channel = self.shell_channel_class(self)
         return self._shell_channel
 
     @property
     def iopub_channel(self):
         if self._iopub_channel is None:
             self._iopub_channel = self.iopub_channel_class(self)
         return self._iopub_channel
 
     @property
     def stdin_channel(self):
         if self._stdin_channel is None:
             self._stdin_channel = self.stdin_channel_class(self)
         return self._stdin_channel
 
     @property
     def hb_channel(self):
         if self._hb_channel is None:
             self._hb_channel = self.hb_channel_class(self)
         return self._hb_channel
 
     # Methods for sending specific messages
     # -------------------------------------
 
     def execute(self, code, silent=False, store_history=True,
                 user_expressions={}, allow_stdin=None):
         if allow_stdin is None:
             allow_stdin = self.allow_stdin
         content = dict(code=code, silent=silent, store_history=store_history,
                        user_expressions=user_expressions,
                        allow_stdin=allow_stdin)
         msg = self.session.msg('execute_request', content)
         self._dispatch_to_kernel(msg)
         return msg['header']['msg_id']
 
     def complete(self, code, cursor_pos=None):
         if cursor_pos is None:
             cursor_pos = len(code)
         content = dict(code=code, cursor_pos=cursor_pos)
         msg = self.session.msg('complete_request', content)
         self._dispatch_to_kernel(msg)
         return msg['header']['msg_id']
 
     def inspect(self, code, cursor_pos=None, detail_level=0):
         if cursor_pos is None:
             cursor_pos = len(code)
         content = dict(code=code, cursor_pos=cursor_pos,
             detail_level=detail_level,
         )
         msg = self.session.msg('inspect_request', content)
         self._dispatch_to_kernel(msg)
         return msg['header']['msg_id']
 
     def history(self, raw=True, output=False, hist_access_type='range', **kwds):
         content = dict(raw=raw, output=output,
                        hist_access_type=hist_access_type, **kwds)
         msg = self.session.msg('history_request', content)
         self._dispatch_to_kernel(msg)
         return msg['header']['msg_id']
 
     def shutdown(self, restart=False):
         # FIXME: What to do here?
         raise NotImplementedError('Cannot shutdown in-process kernel')
 
     def kernel_info(self):
         """Request kernel info."""
         msg = self.session.msg('kernel_info_request')
         self._dispatch_to_kernel(msg)
         return msg['header']['msg_id']
 
     def input(self, string):
         if self.kernel is None:
             raise RuntimeError('Cannot send input reply. No kernel exists.')
         self.kernel.raw_input_str = string
 
 
     def _dispatch_to_kernel(self, msg):
         """ Send a message to the kernel and handle a reply.
         """
         kernel = self.kernel
         if kernel is None:
             raise RuntimeError('Cannot send request. No kernel exists.')
 
         stream = DummySocket()
         self.session.send(stream, msg)
         msg_parts = stream.recv_multipart()
         kernel.dispatch_shell(stream, msg_parts)
 
         idents, reply_msg = self.session.recv(stream, copy=False)
         self.shell_channel.call_handlers_later(reply_msg)
 
 
 #-----------------------------------------------------------------------------
 # ABC Registration
 #-----------------------------------------------------------------------------
 
 KernelClientABC.register(InProcessKernelClient)

IPython/kernel/inprocess/ipkernel.py

@@ -1,169 +1,171 b''
 """An in-process kernel"""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from contextlib import contextmanager
 import logging
 import sys
 
 from IPython.core.interactiveshell import InteractiveShellABC
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import Any, Enum, Instance, List, Type
 from IPython.kernel.zmq.ipkernel import IPythonKernel
 from IPython.kernel.zmq.zmqshell import ZMQInteractiveShell
 
 from .socket import DummySocket
 
 #-----------------------------------------------------------------------------
 # Main kernel class
 #-----------------------------------------------------------------------------
 
 class InProcessKernel(IPythonKernel):
 
     #-------------------------------------------------------------------------
     # InProcessKernel interface
     #-------------------------------------------------------------------------
 
     # The frontends connected to this kernel.
     frontends = List(
-        Instance('IPython.kernel.inprocess.client.InProcessKernelClient')
+        Instance('IPython.kernel.inprocess.client.InProcessKernelClient'
+                 allow_none=True)
     )
 
     # The GUI environment that the kernel is running under. This need not be
     # specified for the normal operation for the kernel, but is required for
     # IPython's GUI support (including pylab). The default is 'inline' because
     # it is safe under all GUI toolkits.
     gui = Enum(('tk', 'gtk', 'wx', 'qt', 'qt4', 'inline'),
                default_value='inline')
 
     raw_input_str = Any()
     stdout = Any()
     stderr = Any()
 
     #-------------------------------------------------------------------------
     # Kernel interface
     #-------------------------------------------------------------------------
 
     shell_class = Type()
     shell_streams = List()
     control_stream = Any()
     iopub_socket = Instance(DummySocket, ())
     stdin_socket = Instance(DummySocket, ())
 
     def __init__(self, **traits):
         super(InProcessKernel, self).__init__(**traits)
 
         self.iopub_socket.on_trait_change(self._io_dispatch, 'message_sent')
         self.shell.kernel = self
 
     def execute_request(self, stream, ident, parent):
         """ Override for temporary IO redirection. """
         with self._redirected_io():
             super(InProcessKernel, self).execute_request(stream, ident, parent)
 
     def start(self):
         """ Override registration of dispatchers for streams. """
         self.shell.exit_now = False
 
     def _abort_queue(self, stream):
         """ The in-process kernel doesn't abort requests. """
         pass
 
     def _input_request(self, prompt, ident, parent, password=False):
         # Flush output before making the request.
         self.raw_input_str = None
         sys.stderr.flush()
         sys.stdout.flush()
 
         # Send the input request.
         content = json_clean(dict(prompt=prompt, password=password))
         msg = self.session.msg(u'input_request', content, parent)
         for frontend in self.frontends:
             if frontend.session.session == parent['header']['session']:
                 frontend.stdin_channel.call_handlers(msg)
                 break
         else:
             logging.error('No frontend found for raw_input request')
             return str()
 
         # Await a response.
         while self.raw_input_str is None:
             frontend.stdin_channel.process_events()
         return self.raw_input_str
 
     #-------------------------------------------------------------------------
     # Protected interface
     #-------------------------------------------------------------------------
 
     @contextmanager
     def _redirected_io(self):
         """ Temporarily redirect IO to the kernel.
         """
         sys_stdout, sys_stderr = sys.stdout, sys.stderr
         sys.stdout, sys.stderr = self.stdout, self.stderr
         yield
         sys.stdout, sys.stderr = sys_stdout, sys_stderr
 
     #------ Trait change handlers --------------------------------------------
 
     def _io_dispatch(self):
         """ Called when a message is sent to the IO socket.
         """
         ident, msg = self.session.recv(self.iopub_socket, copy=False)
         for frontend in self.frontends:
             frontend.iopub_channel.call_handlers(msg)
         
     #------ Trait initializers -----------------------------------------------
 
     def _log_default(self):
         return logging.getLogger(__name__)
 
     def _session_default(self):
         from IPython.kernel.zmq.session import Session
         return Session(parent=self, key=b'')
 
     def _shell_class_default(self):
         return InProcessInteractiveShell
 
     def _stdout_default(self):
         from IPython.kernel.zmq.iostream import OutStream
         return OutStream(self.session, self.iopub_socket, u'stdout', pipe=False)
 
     def _stderr_default(self):
         from IPython.kernel.zmq.iostream import OutStream
         return OutStream(self.session, self.iopub_socket, u'stderr', pipe=False)
 
 #-----------------------------------------------------------------------------
 # Interactive shell subclass
 #-----------------------------------------------------------------------------
 
 class InProcessInteractiveShell(ZMQInteractiveShell):
 
-    kernel = Instance('IPython.kernel.inprocess.ipkernel.InProcessKernel')
+    kernel = Instance('IPython.kernel.inprocess.ipkernel.InProcessKernel',
+                      allow_none=True)
 
     #-------------------------------------------------------------------------
     # InteractiveShell interface
     #-------------------------------------------------------------------------
 
     def enable_gui(self, gui=None):
         """Enable GUI integration for the kernel."""
         from IPython.kernel.zmq.eventloops import enable_gui
         if not gui:
             gui = self.kernel.gui
         return enable_gui(gui, kernel=self.kernel)
 
     def enable_matplotlib(self, gui=None):
         """Enable matplotlib integration for the kernel."""
         if not gui:
             gui = self.kernel.gui
         return super(InProcessInteractiveShell, self).enable_matplotlib(gui)
 
     def enable_pylab(self, gui=None, import_all=True, welcome_message=False):
         """Activate pylab support at runtime."""
         if not gui:
             gui = self.kernel.gui
         return super(InProcessInteractiveShell, self).enable_pylab(gui, import_all,
                                                             welcome_message)
 
 InteractiveShellABC.register(InProcessInteractiveShell)

IPython/kernel/inprocess/manager.py

@@ -1,71 +1,72 b''
 """A kernel manager for in-process kernels."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from IPython.utils.traitlets import Instance, DottedObjectName
 from IPython.kernel.managerabc import KernelManagerABC
 from IPython.kernel.manager import KernelManager
 from IPython.kernel.zmq.session import Session
 
 
 class InProcessKernelManager(KernelManager):
     """A manager for an in-process kernel.
 
     This class implements the interface of
     `IPython.kernel.kernelmanagerabc.KernelManagerABC` and allows
     (asynchronous) frontends to be used seamlessly with an in-process kernel.
 
     See `IPython.kernel.kernelmanager.KernelManager` for docstrings.
     """
 
     # The kernel process with which the KernelManager is communicating.
-    kernel = Instance('IPython.kernel.inprocess.ipkernel.InProcessKernel')
+    kernel = Instance('IPython.kernel.inprocess.ipkernel.InProcessKernel',
+                      allow_none=True)
     # the client class for KM.client() shortcut
     client_class = DottedObjectName('IPython.kernel.inprocess.BlockingInProcessKernelClient')
     
     def _session_default(self):
         # don't sign in-process messages
         return Session(key=b'', parent=self)
     
     #--------------------------------------------------------------------------
     # Kernel management methods
     #--------------------------------------------------------------------------
 
     def start_kernel(self, **kwds):
         from IPython.kernel.inprocess.ipkernel import InProcessKernel
         self.kernel = InProcessKernel(parent=self, session=self.session)
 
     def shutdown_kernel(self):
         self._kill_kernel()
 
     def restart_kernel(self, now=False, **kwds):
         self.shutdown_kernel()
         self.start_kernel(**kwds)
 
     @property
     def has_kernel(self):
         return self.kernel is not None
 
     def _kill_kernel(self):
         self.kernel = None
 
     def interrupt_kernel(self):
         raise NotImplementedError("Cannot interrupt in-process kernel.")
 
     def signal_kernel(self, signum):
         raise NotImplementedError("Cannot signal in-process kernel.")
 
     def is_alive(self):
         return self.kernel is not None
 
     def client(self, **kwargs):
         kwargs['kernel'] = self.kernel
         return super(InProcessKernelManager, self).client(**kwargs)
 
 
 #-----------------------------------------------------------------------------
 # ABC Registration
 #-----------------------------------------------------------------------------
 
 KernelManagerABC.register(InProcessKernelManager)

IPython/kernel/ioloop/manager.py

@@ -1,62 +1,62 b''
 """A kernel manager with a tornado IOLoop"""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2013  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 absolute_import
 
 from zmq.eventloop import ioloop
 from zmq.eventloop.zmqstream import ZMQStream
 
 from IPython.utils.traitlets import (
     Instance
 )
 
 from IPython.kernel.manager import KernelManager
 from .restarter import IOLoopKernelRestarter
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 def as_zmqstream(f):
     def wrapped(self, *args, **kwargs):
         socket = f(self, *args, **kwargs)
         return ZMQStream(socket, self.loop)
     return wrapped
 
 class IOLoopKernelManager(KernelManager):
 
-    loop = Instance('zmq.eventloop.ioloop.IOLoop', allow_none=False)
+    loop = Instance('zmq.eventloop.ioloop.IOLoop')
     def _loop_default(self):
         return ioloop.IOLoop.instance()
 
-    _restarter = Instance('IPython.kernel.ioloop.IOLoopKernelRestarter')
+    _restarter = Instance('IPython.kernel.ioloop.IOLoopKernelRestarter', allow_none=True)
 
     def start_restarter(self):
         if self.autorestart and self.has_kernel:
             if self._restarter is None:
                 self._restarter = IOLoopKernelRestarter(
                     kernel_manager=self, loop=self.loop,
                     parent=self, log=self.log
                 )
             self._restarter.start()
 
     def stop_restarter(self):
         if self.autorestart:
             if self._restarter is not None:
                 self._restarter.stop()
 
     connect_shell = as_zmqstream(KernelManager.connect_shell)
     connect_iopub = as_zmqstream(KernelManager.connect_iopub)
     connect_stdin = as_zmqstream(KernelManager.connect_stdin)
     connect_hb = as_zmqstream(KernelManager.connect_hb)

IPython/kernel/ioloop/restarter.py

@@ -1,54 +1,54 b''
 """A basic in process kernel monitor with autorestarting.
 
 This watches a kernel's state using KernelManager.is_alive and auto
 restarts the kernel if it dies.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2013  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 absolute_import
 
 from zmq.eventloop import ioloop
 
 
 from IPython.kernel.restarter import KernelRestarter
 from IPython.utils.traitlets import (
     Instance,
 )
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 class IOLoopKernelRestarter(KernelRestarter):
     """Monitor and autorestart a kernel."""
 
-    loop = Instance('zmq.eventloop.ioloop.IOLoop', allow_none=False)
+    loop = Instance('zmq.eventloop.ioloop.IOLoop')
     def _loop_default(self):
         return ioloop.IOLoop.instance()
 
     _pcallback = None
 
     def start(self):
         """Start the polling of the kernel."""
         if self._pcallback is None:
             self._pcallback = ioloop.PeriodicCallback(
                 self.poll, 1000*self.time_to_dead, self.loop
             )
             self._pcallback.start()
 
     def stop(self):
         """Stop the kernel polling."""
         if self._pcallback is not None:
             self._pcallback.stop()
             self._pcallback = None
 

IPython/kernel/zmq/datapub.py

@@ -1,70 +1,70 b''
 """Publishing native (typically pickled) objects.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2012  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 IPython.config import Configurable
 from IPython.kernel.inprocess.socket import SocketABC
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import Instance, Dict, CBytes
 from IPython.kernel.zmq.serialize import serialize_object
 from IPython.kernel.zmq.session import Session, extract_header
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 class ZMQDataPublisher(Configurable):
 
     topic = topic = CBytes(b'datapub')
-    session = Instance(Session)
-    pub_socket = Instance(SocketABC)
+    session = Instance(Session, allow_none=True)
+    pub_socket = Instance(SocketABC, allow_none=True)
     parent_header = Dict({})
 
     def set_parent(self, parent):
         """Set the parent for outbound messages."""
         self.parent_header = extract_header(parent)
     
     def publish_data(self, data):
         """publish a data_message on the IOPub channel
     
         Parameters
         ----------
     
         data : dict
             The data to be published. Think of it as a namespace.
         """
         session = self.session
         buffers = serialize_object(data,
             buffer_threshold=session.buffer_threshold,
             item_threshold=session.item_threshold,
         )
         content = json_clean(dict(keys=data.keys()))
         session.send(self.pub_socket, 'data_message', content=content,
             parent=self.parent_header,
             buffers=buffers,
             ident=self.topic,
         )
 
 
 def publish_data(data):
     """publish a data_message on the IOPub channel
     
     Parameters
     ----------
     
     data : dict
         The data to be published. Think of it as a namespace.
     """
     from IPython.kernel.zmq.zmqshell import ZMQInteractiveShell
     ZMQInteractiveShell.instance().data_pub.publish_data(data)

IPython/kernel/zmq/displayhook.py

@@ -1,74 +1,74 b''
 """Replacements for sys.displayhook that publish over ZMQ."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import sys
 
 from IPython.core.displayhook import DisplayHook
 from IPython.kernel.inprocess.socket import SocketABC
 from IPython.utils.jsonutil import encode_images
 from IPython.utils.py3compat import builtin_mod
 from IPython.utils.traitlets import Instance, Dict
 from .session import extract_header, Session
 
 class ZMQDisplayHook(object):
     """A simple displayhook that publishes the object's repr over a ZeroMQ
     socket."""
     topic=b'execute_result'
 
     def __init__(self, session, pub_socket):
         self.session = session
         self.pub_socket = pub_socket
         self.parent_header = {}
 
     def __call__(self, obj):
         if obj is None:
             return
 
         builtin_mod._ = obj
         sys.stdout.flush()
         sys.stderr.flush()
         msg = self.session.send(self.pub_socket, u'execute_result', {u'data':repr(obj)},
                                parent=self.parent_header, ident=self.topic)
 
     def set_parent(self, parent):
         self.parent_header = extract_header(parent)
 
 
 class ZMQShellDisplayHook(DisplayHook):
     """A displayhook subclass that publishes data using ZeroMQ. This is intended
     to work with an InteractiveShell instance. It sends a dict of different
     representations of the object."""
     topic=None
 
-    session = Instance(Session)
-    pub_socket = Instance(SocketABC)
+    session = Instance(Session, allow_none=True)
+    pub_socket = Instance(SocketABC, allow_none=True)
     parent_header = Dict({})
 
     def set_parent(self, parent):
         """Set the parent for outbound messages."""
         self.parent_header = extract_header(parent)
 
     def start_displayhook(self):
         self.msg = self.session.msg(u'execute_result', {
             'data': {},
             'metadata': {},
         }, parent=self.parent_header)
 
     def write_output_prompt(self):
         """Write the output prompt."""
         self.msg['content']['execution_count'] = self.prompt_count
 
     def write_format_data(self, format_dict, md_dict=None):
         self.msg['content']['data'] = encode_images(format_dict)
         self.msg['content']['metadata'] = md_dict
 
     def finish_displayhook(self):
         """Finish up all displayhook activities."""
         sys.stdout.flush()
         sys.stderr.flush()
         if self.msg['content']['data']:
             self.session.send(self.pub_socket, self.msg, ident=self.topic)
         self.msg = None
 

IPython/kernel/zmq/ipkernel.py

@@ -1,367 +1,368 b''
 """The IPython kernel implementation"""
 
 import getpass
 import sys
 import traceback
 
 from IPython.core import release
 from IPython.utils.py3compat import builtin_mod, PY3
 from IPython.utils.tokenutil import token_at_cursor, line_at_cursor
 from IPython.utils.traitlets import Instance, Type, Any, List
 from IPython.utils.decorators import undoc
 
 from ..comm import CommManager
 from .kernelbase import Kernel as KernelBase
 from .serialize import serialize_object, unpack_apply_message
 from .zmqshell import ZMQInteractiveShell
 
 
 def lazy_import_handle_comm_opened(*args, **kwargs):
     from IPython.html.widgets import Widget
     Widget.handle_comm_opened(*args, **kwargs)
 
 
 class IPythonKernel(KernelBase):
-    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
+    shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
+                     allow_none=True)
     shell_class = Type(ZMQInteractiveShell)
 
     user_module = Any()
     def _user_module_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_module = new
 
     user_ns = Instance(dict, args=None, allow_none=True)
     def _user_ns_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_ns = new
             self.shell.init_user_ns()
 
     # A reference to the Python builtin 'raw_input' function.
     # (i.e., __builtin__.raw_input for Python 2.7, builtins.input for Python 3)
     _sys_raw_input = Any()
     _sys_eval_input = Any()
 
     def __init__(self, **kwargs):
         super(IPythonKernel, self).__init__(**kwargs)
 
         # Initialize the InteractiveShell subclass
         self.shell = self.shell_class.instance(parent=self,
             profile_dir = self.profile_dir,
             user_module = self.user_module,
             user_ns     = self.user_ns,
             kernel      = self,
         )
         self.shell.displayhook.session = self.session
         self.shell.displayhook.pub_socket = self.iopub_socket
         self.shell.displayhook.topic = self._topic('execute_result')
         self.shell.display_pub.session = self.session
         self.shell.display_pub.pub_socket = self.iopub_socket
         self.shell.data_pub.session = self.session
         self.shell.data_pub.pub_socket = self.iopub_socket
 
         # TMP - hack while developing
         self.shell._reply_content = None
 
         self.comm_manager = CommManager(shell=self.shell, parent=self, 
                                         kernel=self)
         self.comm_manager.register_target('ipython.widget', lazy_import_handle_comm_opened)
 
         self.shell.configurables.append(self.comm_manager)
         comm_msg_types = [ 'comm_open', 'comm_msg', 'comm_close' ]
         for msg_type in comm_msg_types:
             self.shell_handlers[msg_type] = getattr(self.comm_manager, msg_type)
     
     help_links = List([
         {
             'text': "Python",
             'url': "http://docs.python.org/%i.%i" % sys.version_info[:2],
         },
         {
             'text': "IPython",
             'url': "http://ipython.org/documentation.html",
         },
         {
             'text': "NumPy",
             'url': "http://docs.scipy.org/doc/numpy/reference/",
         },
         {
             'text': "SciPy",
             'url': "http://docs.scipy.org/doc/scipy/reference/",
         },
         {
             'text': "Matplotlib",
             'url': "http://matplotlib.org/contents.html",
         },
         {
             'text': "SymPy",
             'url': "http://docs.sympy.org/latest/index.html",
         },
         {
             'text': "pandas",
             'url': "http://pandas.pydata.org/pandas-docs/stable/",
         },
     ])
 
     # Kernel info fields
     implementation = 'ipython'
     implementation_version = release.version
     language_info = {
                      'name': 'python',
                      'version': sys.version.split()[0],
                      'mimetype': 'text/x-python',
                      'codemirror_mode': {'name': 'ipython',
                                          'version': sys.version_info[0]},
                      'pygments_lexer': 'ipython%d' % (3 if PY3 else 2),
                      'nbconvert_exporter': 'python',
                      'file_extension': '.py'
                     }
     @property
     def banner(self):
         return self.shell.banner
 
     def start(self):
         self.shell.exit_now = False
         super(IPythonKernel, self).start()
 
     def set_parent(self, ident, parent):
         """Overridden from parent to tell the display hook and output streams
         about the parent message.
         """
         super(IPythonKernel, self).set_parent(ident, parent)
         self.shell.set_parent(parent)
 
     def _forward_input(self, allow_stdin=False):
         """Forward raw_input and getpass to the current frontend.
 
         via input_request
         """
         self._allow_stdin = allow_stdin
 
         if PY3:
             self._sys_raw_input = builtin_mod.input
             builtin_mod.input = self.raw_input
         else:
             self._sys_raw_input = builtin_mod.raw_input
             self._sys_eval_input = builtin_mod.input
             builtin_mod.raw_input = self.raw_input
             builtin_mod.input = lambda prompt='': eval(self.raw_input(prompt))
         self._save_getpass = getpass.getpass
         getpass.getpass = self.getpass
 
     def _restore_input(self):
         """Restore raw_input, getpass"""
         if PY3:
             builtin_mod.input = self._sys_raw_input
         else:
             builtin_mod.raw_input = self._sys_raw_input
             builtin_mod.input = self._sys_eval_input
 
         getpass.getpass = self._save_getpass
 
     @property
     def execution_count(self):
         return self.shell.execution_count
 
     @execution_count.setter
     def execution_count(self, value):
         # Ignore the incrememnting done by KernelBase, in favour of our shell's
         # execution counter.
         pass
 
     def do_execute(self, code, silent, store_history=True,
                    user_expressions=None, allow_stdin=False):
         shell = self.shell # we'll need this a lot here
 
         self._forward_input(allow_stdin)
 
         reply_content = {}
         # FIXME: the shell calls the exception handler itself.
         shell._reply_content = None
         try:
             shell.run_cell(code, store_history=store_history, silent=silent)
         except:
             status = u'error'
             # FIXME: this code right now isn't being used yet by default,
             # because the run_cell() call above directly fires off exception
             # reporting.  This code, therefore, is only active in the scenario
             # where runlines itself has an unhandled exception.  We need to
             # uniformize this, for all exception construction to come from a
             # single location in the codbase.
             etype, evalue, tb = sys.exc_info()
             tb_list = traceback.format_exception(etype, evalue, tb)
             reply_content.update(shell._showtraceback(etype, evalue, tb_list))
         else:
             status = u'ok'
         finally:
             self._restore_input()
 
         reply_content[u'status'] = status
 
         # Return the execution counter so clients can display prompts
         reply_content['execution_count'] = shell.execution_count - 1
 
         # FIXME - fish exception info out of shell, possibly left there by
         # runlines.  We'll need to clean up this logic later.
         if shell._reply_content is not None:
             reply_content.update(shell._reply_content)
             e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='execute')
             reply_content['engine_info'] = e_info
             # reset after use
             shell._reply_content = None
 
         if 'traceback' in reply_content:
             self.log.info("Exception in execute request:\n%s", '\n'.join(reply_content['traceback']))
 
 
         # At this point, we can tell whether the main code execution succeeded
         # or not.  If it did, we proceed to evaluate user_expressions
         if reply_content['status'] == 'ok':
             reply_content[u'user_expressions'] = \
                          shell.user_expressions(user_expressions or {})
         else:
             # If there was an error, don't even try to compute expressions
             reply_content[u'user_expressions'] = {}
 
         # Payloads should be retrieved regardless of outcome, so we can both
         # recover partial output (that could have been generated early in a
         # block, before an error) and clear the payload system always.
         reply_content[u'payload'] = shell.payload_manager.read_payload()
         # Be agressive about clearing the payload because we don't want
         # it to sit in memory until the next execute_request comes in.
         shell.payload_manager.clear_payload()
 
         return reply_content
 
     def do_complete(self, code, cursor_pos):
         # FIXME: IPython completers currently assume single line,
         # but completion messages give multi-line context
         # For now, extract line from cell, based on cursor_pos:
         if cursor_pos is None:
             cursor_pos = len(code)
         line, offset = line_at_cursor(code, cursor_pos)
         line_cursor = cursor_pos - offset
 
         txt, matches = self.shell.complete('', line, line_cursor)
         return {'matches' : matches,
                 'cursor_end' : cursor_pos,
                 'cursor_start' : cursor_pos - len(txt),
                 'metadata' : {},
                 'status' : 'ok'}
 
     def do_inspect(self, code, cursor_pos, detail_level=0):
         name = token_at_cursor(code, cursor_pos)
         info = self.shell.object_inspect(name)
 
         reply_content = {'status' : 'ok'}
         reply_content['data'] = data = {}
         reply_content['metadata'] = {}
         reply_content['found'] = info['found']
         if info['found']:
             info_text = self.shell.object_inspect_text(
                 name,
                 detail_level=detail_level,
             )
             data['text/plain'] = info_text
 
         return reply_content
 
     def do_history(self, hist_access_type, output, raw, session=None, start=None,
                    stop=None, n=None, pattern=None, unique=False):
         if hist_access_type == 'tail':
             hist = self.shell.history_manager.get_tail(n, raw=raw, output=output,
                                                             include_latest=True)
 
         elif hist_access_type == 'range':
             hist = self.shell.history_manager.get_range(session, start, stop,
                                                         raw=raw, output=output)
 
         elif hist_access_type == 'search':
             hist = self.shell.history_manager.search(
                 pattern, raw=raw, output=output, n=n, unique=unique)
         else:
             hist = []
 
         return {'history' : list(hist)}
 
     def do_shutdown(self, restart):
         self.shell.exit_now = True
         return dict(status='ok', restart=restart)
 
     def do_is_complete(self, code):
         status, indent_spaces = self.shell.input_transformer_manager.check_complete(code)
         r = {'status': status}
         if status == 'incomplete':
             r['indent'] = ' ' * indent_spaces
         return r
 
     def do_apply(self, content, bufs, msg_id, reply_metadata):
         shell = self.shell
         try:
             working = shell.user_ns
 
             prefix = "_"+str(msg_id).replace("-","")+"_"
 
             f,args,kwargs = unpack_apply_message(bufs, working, copy=False)
 
             fname = getattr(f, '__name__', 'f')
 
             fname = prefix+"f"
             argname = prefix+"args"
             kwargname = prefix+"kwargs"
             resultname = prefix+"result"
 
             ns = { fname : f, argname : args, kwargname : kwargs , resultname : None }
             # print ns
             working.update(ns)
             code = "%s = %s(*%s,**%s)" % (resultname, fname, argname, kwargname)
             try:
                 exec(code, shell.user_global_ns, shell.user_ns)
                 result = working.get(resultname)
             finally:
                 for key in ns:
                     working.pop(key)
 
             result_buf = serialize_object(result,
                 buffer_threshold=self.session.buffer_threshold,
                 item_threshold=self.session.item_threshold,
             )
 
         except:
             # invoke IPython traceback formatting
             shell.showtraceback()
             # FIXME - fish exception info out of shell, possibly left there by
             # run_code.  We'll need to clean up this logic later.
             reply_content = {}
             if shell._reply_content is not None:
                 reply_content.update(shell._reply_content)
                 e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='apply')
                 reply_content['engine_info'] = e_info
                 # reset after use
                 shell._reply_content = None
 
             self.send_response(self.iopub_socket, u'error', reply_content,
                                 ident=self._topic('error'))
             self.log.info("Exception in apply request:\n%s", '\n'.join(reply_content['traceback']))
             result_buf = []
 
             if reply_content['ename'] == 'UnmetDependency':
                 reply_metadata['dependencies_met'] = False
         else:
             reply_content = {'status' : 'ok'}
 
         return reply_content, result_buf
 
     def do_clear(self):
         self.shell.reset(False)
         return dict(status='ok')
 
 
 # This exists only for backwards compatibility - use IPythonKernel instead
 
 @undoc
 class Kernel(IPythonKernel):
     def __init__(self, *args, **kwargs):
         import warnings
         warnings.warn('Kernel is a deprecated alias of IPython.kernel.zmq.ipkernel.IPythonKernel',
                       DeprecationWarning)
-        super(Kernel, self).__init__(*args, **kwargs)
  No newline at end of file
+        super(Kernel, self).__init__(*args, **kwargs)

IPython/kernel/zmq/kernelapp.py

@@ -1,387 +1,387 b''
 """An Application for launching a kernel"""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import atexit
 import os
 import sys
 import signal
 
 import zmq
 from zmq.eventloop import ioloop
 from zmq.eventloop.zmqstream import ZMQStream
 
 from IPython.core.ultratb import FormattedTB
 from IPython.core.application import (
     BaseIPythonApplication, base_flags, base_aliases, catch_config_error
 )
 from IPython.core.profiledir import ProfileDir
 from IPython.core.shellapp import (
     InteractiveShellApp, shell_flags, shell_aliases
 )
 from IPython.utils import io
 from IPython.utils.path import filefind
 from IPython.utils.traitlets import (
     Any, Instance, Dict, Unicode, Integer, Bool, DottedObjectName, Type,
 )
 from IPython.utils.importstring import import_item
 from IPython.kernel import write_connection_file
 from IPython.kernel.connect import ConnectionFileMixin
 
 # local imports
 from .heartbeat import Heartbeat
 from .ipkernel import IPythonKernel
 from .parentpoller import ParentPollerUnix, ParentPollerWindows
 from .session import (
     Session, session_flags, session_aliases,
 )
 from .zmqshell import ZMQInteractiveShell
 
 #-----------------------------------------------------------------------------
 # Flags and Aliases
 #-----------------------------------------------------------------------------
 
 kernel_aliases = dict(base_aliases)
 kernel_aliases.update({
     'ip' : 'IPKernelApp.ip',
     'hb' : 'IPKernelApp.hb_port',
     'shell' : 'IPKernelApp.shell_port',
     'iopub' : 'IPKernelApp.iopub_port',
     'stdin' : 'IPKernelApp.stdin_port',
     'control' : 'IPKernelApp.control_port',
     'f' : 'IPKernelApp.connection_file',
     'transport': 'IPKernelApp.transport',
 })
 
 kernel_flags = dict(base_flags)
 kernel_flags.update({
     'no-stdout' : (
             {'IPKernelApp' : {'no_stdout' : True}},
             "redirect stdout to the null device"),
     'no-stderr' : (
             {'IPKernelApp' : {'no_stderr' : True}},
             "redirect stderr to the null device"),
     'pylab' : (
         {'IPKernelApp' : {'pylab' : 'auto'}},
         """Pre-load matplotlib and numpy for interactive use with
         the default matplotlib backend."""),
 })
 
 # inherit flags&aliases for any IPython shell apps
 kernel_aliases.update(shell_aliases)
 kernel_flags.update(shell_flags)
 
 # inherit flags&aliases for Sessions
 kernel_aliases.update(session_aliases)
 kernel_flags.update(session_flags)
 
 _ctrl_c_message = """\
 NOTE: When using the `ipython kernel` entry point, Ctrl-C will not work.
 
 To exit, you will have to explicitly quit this process, by either sending
 "quit" from a client, or using Ctrl-\\ in UNIX-like environments.
 
 To read more about this, see https://github.com/ipython/ipython/issues/2049
 
 """
 
 #-----------------------------------------------------------------------------
 # Application class for starting an IPython Kernel
 #-----------------------------------------------------------------------------
 
 class IPKernelApp(BaseIPythonApplication, InteractiveShellApp,
         ConnectionFileMixin):
     name='ipython-kernel'
     aliases = Dict(kernel_aliases)
     flags = Dict(kernel_flags)
     classes = [IPythonKernel, ZMQInteractiveShell, ProfileDir, Session]
     # the kernel class, as an importstring
     kernel_class = Type('IPython.kernel.zmq.ipkernel.IPythonKernel', config=True,
                         klass='IPython.kernel.zmq.kernelbase.Kernel',
     help="""The Kernel subclass to be used.
     
     This should allow easy re-use of the IPKernelApp entry point
     to configure and launch kernels other than IPython's own.
     """)
     kernel = Any()
     poller = Any() # don't restrict this even though current pollers are all Threads
-    heartbeat = Instance(Heartbeat)
+    heartbeat = Instance(Heartbeat, allow_none=True)
     ports = Dict()
     
     # connection info:
     
     @property
     def abs_connection_file(self):
         if os.path.basename(self.connection_file) == self.connection_file:
             return os.path.join(self.profile_dir.security_dir, self.connection_file)
         else:
             return self.connection_file
         
 
     # streams, etc.
     no_stdout = Bool(False, config=True, help="redirect stdout to the null device")
     no_stderr = Bool(False, config=True, help="redirect stderr to the null device")
     outstream_class = DottedObjectName('IPython.kernel.zmq.iostream.OutStream',
         config=True, help="The importstring for the OutStream factory")
     displayhook_class = DottedObjectName('IPython.kernel.zmq.displayhook.ZMQDisplayHook',
         config=True, help="The importstring for the DisplayHook factory")
 
     # polling
     parent_handle = Integer(int(os.environ.get('JPY_PARENT_PID') or 0), config=True,
         help="""kill this process if its parent dies.  On Windows, the argument
         specifies the HANDLE of the parent process, otherwise it is simply boolean.
         """)
     interrupt = Integer(int(os.environ.get('JPY_INTERRUPT_EVENT') or 0), config=True,
         help="""ONLY USED ON WINDOWS
         Interrupt this process when the parent is signaled.
         """)
 
     def init_crash_handler(self):
         # Install minimal exception handling
         sys.excepthook = FormattedTB(mode='Verbose', color_scheme='NoColor',
                                      ostream=sys.__stdout__)
 
     def init_poller(self):
         if sys.platform == 'win32':
             if self.interrupt or self.parent_handle:
                 self.poller = ParentPollerWindows(self.interrupt, self.parent_handle)
         elif self.parent_handle:
             self.poller = ParentPollerUnix()
 
     def _bind_socket(self, s, port):
         iface = '%s://%s' % (self.transport, self.ip)
         if self.transport == 'tcp':
             if port <= 0:
                 port = s.bind_to_random_port(iface)
             else:
                 s.bind("tcp://%s:%i" % (self.ip, port))
         elif self.transport == 'ipc':
             if port <= 0:
                 port = 1
                 path = "%s-%i" % (self.ip, port)
                 while os.path.exists(path):
                     port = port + 1
                     path = "%s-%i" % (self.ip, port)
             else:
                 path = "%s-%i" % (self.ip, port)
             s.bind("ipc://%s" % path)
         return port
 
     def write_connection_file(self):
         """write connection info to JSON file"""
         cf = self.abs_connection_file
         self.log.debug("Writing connection file: %s", cf)
         write_connection_file(cf, ip=self.ip, key=self.session.key, transport=self.transport,
         shell_port=self.shell_port, stdin_port=self.stdin_port, hb_port=self.hb_port,
         iopub_port=self.iopub_port, control_port=self.control_port)
     
     def cleanup_connection_file(self):
         cf = self.abs_connection_file
         self.log.debug("Cleaning up connection file: %s", cf)
         try:
             os.remove(cf)
         except (IOError, OSError):
             pass
         
         self.cleanup_ipc_files()
     
     def init_connection_file(self):
         if not self.connection_file:
             self.connection_file = "kernel-%s.json"%os.getpid()
         try:
             self.connection_file = filefind(self.connection_file, ['.', self.profile_dir.security_dir])
         except IOError:
             self.log.debug("Connection file not found: %s", self.connection_file)
             # This means I own it, so I will clean it up:
             atexit.register(self.cleanup_connection_file)
             return
         try:
             self.load_connection_file()
         except Exception:
             self.log.error("Failed to load connection file: %r", self.connection_file, exc_info=True)
             self.exit(1)
     
     def init_sockets(self):
         # Create a context, a session, and the kernel sockets.
         self.log.info("Starting the kernel at pid: %i", os.getpid())
         context = zmq.Context.instance()
         # Uncomment this to try closing the context.
         # atexit.register(context.term)
 
         self.shell_socket = context.socket(zmq.ROUTER)
         self.shell_socket.linger = 1000
         self.shell_port = self._bind_socket(self.shell_socket, self.shell_port)
         self.log.debug("shell ROUTER Channel on port: %i" % self.shell_port)
 
         self.iopub_socket = context.socket(zmq.PUB)
         self.iopub_socket.linger = 1000
         self.iopub_port = self._bind_socket(self.iopub_socket, self.iopub_port)
         self.log.debug("iopub PUB Channel on port: %i" % self.iopub_port)
 
         self.stdin_socket = context.socket(zmq.ROUTER)
         self.stdin_socket.linger = 1000
         self.stdin_port = self._bind_socket(self.stdin_socket, self.stdin_port)
         self.log.debug("stdin ROUTER Channel on port: %i" % self.stdin_port)
 
         self.control_socket = context.socket(zmq.ROUTER)
         self.control_socket.linger = 1000
         self.control_port = self._bind_socket(self.control_socket, self.control_port)
         self.log.debug("control ROUTER Channel on port: %i" % self.control_port)
     
     def init_heartbeat(self):
         """start the heart beating"""
         # heartbeat doesn't share context, because it mustn't be blocked
         # by the GIL, which is accessed by libzmq when freeing zero-copy messages
         hb_ctx = zmq.Context()
         self.heartbeat = Heartbeat(hb_ctx, (self.transport, self.ip, self.hb_port))
         self.hb_port = self.heartbeat.port
         self.log.debug("Heartbeat REP Channel on port: %i" % self.hb_port)
         self.heartbeat.start()
     
     def log_connection_info(self):
         """display connection info, and store ports"""
         basename = os.path.basename(self.connection_file)
         if basename == self.connection_file or \
             os.path.dirname(self.connection_file) == self.profile_dir.security_dir:
             # use shortname
             tail = basename
             if self.profile != 'default':
                 tail += " --profile %s" % self.profile
         else:
             tail = self.connection_file
         lines = [
             "To connect another client to this kernel, use:",
             "    --existing %s" % tail,
         ]
         # log connection info
         # info-level, so often not shown.
         # frontends should use the %connect_info magic
         # to see the connection info
         for line in lines:
             self.log.info(line)
         # also raw print to the terminal if no parent_handle (`ipython kernel`)
         if not self.parent_handle:
             io.rprint(_ctrl_c_message)
             for line in lines:
                 io.rprint(line)
 
         self.ports = dict(shell=self.shell_port, iopub=self.iopub_port,
                                 stdin=self.stdin_port, hb=self.hb_port,
                                 control=self.control_port)
 
     def init_blackhole(self):
         """redirects stdout/stderr to devnull if necessary"""
         if self.no_stdout or self.no_stderr:
             blackhole = open(os.devnull, 'w')
             if self.no_stdout:
                 sys.stdout = sys.__stdout__ = blackhole
             if self.no_stderr:
                 sys.stderr = sys.__stderr__ = blackhole
     
     def init_io(self):
         """Redirect input streams and set a display hook."""
         if self.outstream_class:
             outstream_factory = import_item(str(self.outstream_class))
             sys.stdout = outstream_factory(self.session, self.iopub_socket, u'stdout')
             sys.stderr = outstream_factory(self.session, self.iopub_socket, u'stderr')
         if self.displayhook_class:
             displayhook_factory = import_item(str(self.displayhook_class))
             sys.displayhook = displayhook_factory(self.session, self.iopub_socket)
 
     def init_signal(self):
         signal.signal(signal.SIGINT, signal.SIG_IGN)
 
     def init_kernel(self):
         """Create the Kernel object itself"""
         shell_stream = ZMQStream(self.shell_socket)
         control_stream = ZMQStream(self.control_socket)
         
         kernel_factory = self.kernel_class.instance
 
         kernel = kernel_factory(parent=self, session=self.session,
                                 shell_streams=[shell_stream, control_stream],
                                 iopub_socket=self.iopub_socket,
                                 stdin_socket=self.stdin_socket,
                                 log=self.log,
                                 profile_dir=self.profile_dir,
                                 user_ns=self.user_ns,
         )
         kernel.record_ports(self.ports)
         self.kernel = kernel
 
     def init_gui_pylab(self):
         """Enable GUI event loop integration, taking pylab into account."""
 
         # Provide a wrapper for :meth:`InteractiveShellApp.init_gui_pylab`
         # to ensure that any exception is printed straight to stderr.
         # Normally _showtraceback associates the reply with an execution,
         # which means frontends will never draw it, as this exception
         # is not associated with any execute request.
 
         shell = self.shell
         _showtraceback = shell._showtraceback
         try:
             # replace error-sending traceback with stderr
             def print_tb(etype, evalue, stb):
                 print ("GUI event loop or pylab initialization failed",
                        file=io.stderr)
                 print (shell.InteractiveTB.stb2text(stb), file=io.stderr)
             shell._showtraceback = print_tb
             InteractiveShellApp.init_gui_pylab(self)
         finally:
             shell._showtraceback = _showtraceback
 
     def init_shell(self):
         self.shell = getattr(self.kernel, 'shell', None)
         if self.shell:
             self.shell.configurables.append(self)
 
     @catch_config_error
     def initialize(self, argv=None):
         super(IPKernelApp, self).initialize(argv)
         self.init_blackhole()
         self.init_connection_file()
         self.init_poller()
         self.init_sockets()
         self.init_heartbeat()
         # writing/displaying connection info must be *after* init_sockets/heartbeat
         self.log_connection_info()
         self.write_connection_file()
         self.init_io()
         self.init_signal()
         self.init_kernel()
         # shell init steps
         self.init_path()
         self.init_shell()
         if self.shell:
             self.init_gui_pylab()
             self.init_extensions()
             self.init_code()
         # flush stdout/stderr, so that anything written to these streams during
         # initialization do not get associated with the first execution request
         sys.stdout.flush()
         sys.stderr.flush()
 
     def start(self):
         if self.poller is not None:
             self.poller.start()
         self.kernel.start()
         try:
             ioloop.IOLoop.instance().start()
         except KeyboardInterrupt:
             pass
 
 launch_new_instance = IPKernelApp.launch_instance
 
 def main():
     """Run an IPKernel as an application"""
     app = IPKernelApp.instance()
     app.initialize()
     app.start()
 
 
 if __name__ == '__main__':
     main()

IPython/kernel/zmq/kernelbase.py

@@ -1,701 +1,701 b''
 """Base class for a kernel that talks to frontends over 0MQ."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import sys
 import time
 import logging
 import uuid
 
 from datetime import datetime
 from signal import (
         signal, default_int_handler, SIGINT
 )
 
 import zmq
 from zmq.eventloop import ioloop
 from zmq.eventloop.zmqstream import ZMQStream
 
 from IPython.config.configurable import SingletonConfigurable
 from IPython.core.error import StdinNotImplementedError
 from IPython.core import release
 from IPython.utils import py3compat
 from IPython.utils.py3compat import unicode_type, string_types
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import (
     Any, Instance, Float, Dict, List, Set, Integer, Unicode, Bool,
 )
 
 from .session import Session
 
 
 class Kernel(SingletonConfigurable):
 
     #---------------------------------------------------------------------------
     # Kernel interface
     #---------------------------------------------------------------------------
 
     # attribute to override with a GUI
     eventloop = Any(None)
     def _eventloop_changed(self, name, old, new):
         """schedule call to eventloop from IOLoop"""
         loop = ioloop.IOLoop.instance()
         loop.add_callback(self.enter_eventloop)
 
-    session = Instance(Session)
-    profile_dir = Instance('IPython.core.profiledir.ProfileDir')
+    session = Instance(Session, allow_none=True)
+    profile_dir = Instance('IPython.core.profiledir.ProfileDir', allow_none=True)
     shell_streams = List()
-    control_stream = Instance(ZMQStream)
-    iopub_socket = Instance(zmq.Socket)
-    stdin_socket = Instance(zmq.Socket)
-    log = Instance(logging.Logger)
+    control_stream = Instance(ZMQStream, allow_none=True)
+    iopub_socket = Instance(zmq.Socket, allow_none=True)
+    stdin_socket = Instance(zmq.Socket, allow_none=True)
+    log = Instance(logging.Logger, allow_none=True)
 
     # identities:
     int_id = Integer(-1)
     ident = Unicode()
 
     def _ident_default(self):
         return unicode_type(uuid.uuid4())
 
     # This should be overridden by wrapper kernels that implement any real
     # language.
     language_info = {}
     
     # any links that should go in the help menu
     help_links = List()
 
     # Private interface
     
     _darwin_app_nap = Bool(True, config=True,
         help="""Whether to use appnope for compatiblity with OS X App Nap.
         
         Only affects OS X >= 10.9.
         """
     )
 
     # track associations with current request
     _allow_stdin = Bool(False)
     _parent_header = Dict()
     _parent_ident = Any(b'')
     # Time to sleep after flushing the stdout/err buffers in each execute
     # cycle.  While this introduces a hard limit on the minimal latency of the
     # execute cycle, it helps prevent output synchronization problems for
     # clients.
     # Units are in seconds.  The minimum zmq latency on local host is probably
     # ~150 microseconds, set this to 500us for now.  We may need to increase it
     # a little if it's not enough after more interactive testing.
     _execute_sleep = Float(0.0005, config=True)
 
     # Frequency of the kernel's event loop.
     # Units are in seconds, kernel subclasses for GUI toolkits may need to
     # adapt to milliseconds.
     _poll_interval = Float(0.05, config=True)
 
     # If the shutdown was requested over the network, we leave here the
     # necessary reply message so it can be sent by our registered atexit
     # handler.  This ensures that the reply is only sent to clients truly at
     # the end of our shutdown process (which happens after the underlying
     # IPython shell's own shutdown).
     _shutdown_message = None
 
     # This is a dict of port number that the kernel is listening on. It is set
     # by record_ports and used by connect_request.
     _recorded_ports = Dict()
 
     # set of aborted msg_ids
     aborted = Set()
 
     # Track execution count here. For IPython, we override this to use the
     # execution count we store in the shell.
     execution_count = 0
 
 
     def __init__(self, **kwargs):
         super(Kernel, self).__init__(**kwargs)
 
         # Build dict of handlers for message types
         msg_types = [ 'execute_request', 'complete_request',
                       'inspect_request', 'history_request',
                       'kernel_info_request',
                       'connect_request', 'shutdown_request',
                       'apply_request', 'is_complete_request',
                     ]
         self.shell_handlers = {}
         for msg_type in msg_types:
             self.shell_handlers[msg_type] = getattr(self, msg_type)
         
         control_msg_types = msg_types + [ 'clear_request', 'abort_request' ]
         self.control_handlers = {}
         for msg_type in control_msg_types:
             self.control_handlers[msg_type] = getattr(self, msg_type)
 
     
     def dispatch_control(self, msg):
         """dispatch control requests"""
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.deserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Control Message", exc_info=True)
             return
 
         self.log.debug("Control received: %s", msg)
         
         # Set the parent message for side effects.
         self.set_parent(idents, msg)
         self._publish_status(u'busy')
         
         header = msg['header']
         msg_type = header['msg_type']
 
         handler = self.control_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN CONTROL MESSAGE TYPE: %r", msg_type)
         else:
             try:
                 handler(self.control_stream, idents, msg)
             except Exception:
                 self.log.error("Exception in control handler:", exc_info=True)
         
         sys.stdout.flush()
         sys.stderr.flush()
         self._publish_status(u'idle')
     
     def dispatch_shell(self, stream, msg):
         """dispatch shell requests"""
         # flush control requests first
         if self.control_stream:
             self.control_stream.flush()
         
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.deserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Message", exc_info=True)
             return
 
         # Set the parent message for side effects.
         self.set_parent(idents, msg)
         self._publish_status(u'busy')
         
         header = msg['header']
         msg_id = header['msg_id']
         msg_type = msg['header']['msg_type']
         
         # Print some info about this message and leave a '--->' marker, so it's
         # easier to trace visually the message chain when debugging.  Each
         # handler prints its message at the end.
         self.log.debug('\n*** MESSAGE TYPE:%s***', msg_type)
         self.log.debug('   Content: %s\n   --->\n   ', msg['content'])
 
         if msg_id in self.aborted:
             self.aborted.remove(msg_id)
             # is it safe to assume a msg_id will not be resubmitted?
             reply_type = msg_type.split('_')[0] + '_reply'
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             return
         
         handler = self.shell_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN MESSAGE TYPE: %r", msg_type)
         else:
             # ensure default_int_handler during handler call
             sig = signal(SIGINT, default_int_handler)
             self.log.debug("%s: %s", msg_type, msg)
             try:
                 handler(stream, idents, msg)
             except Exception:
                 self.log.error("Exception in message handler:", exc_info=True)
             finally:
                 signal(SIGINT, sig)
         
         sys.stdout.flush()
         sys.stderr.flush()
         self._publish_status(u'idle')
     
     def enter_eventloop(self):
         """enter eventloop"""
         self.log.info("entering eventloop %s", self.eventloop)
         for stream in self.shell_streams:
             # flush any pending replies,
             # which may be skipped by entering the eventloop
             stream.flush(zmq.POLLOUT)
         # restore default_int_handler
         signal(SIGINT, default_int_handler)
         while self.eventloop is not None:
             try:
                 self.eventloop(self)
             except KeyboardInterrupt:
                 # Ctrl-C shouldn't crash the kernel
                 self.log.error("KeyboardInterrupt caught in kernel")
                 continue
             else:
                 # eventloop exited cleanly, this means we should stop (right?)
                 self.eventloop = None
                 break
         self.log.info("exiting eventloop")
 
     def start(self):
         """register dispatchers for streams"""
         if self.control_stream:
             self.control_stream.on_recv(self.dispatch_control, copy=False)
 
         def make_dispatcher(stream):
             def dispatcher(msg):
                 return self.dispatch_shell(stream, msg)
             return dispatcher
 
         for s in self.shell_streams:
             s.on_recv(make_dispatcher(s), copy=False)
 
         # publish idle status
         self._publish_status('starting')
     
     def do_one_iteration(self):
         """step eventloop just once"""
         if self.control_stream:
             self.control_stream.flush()
         for stream in self.shell_streams:
             # handle at most one request per iteration
             stream.flush(zmq.POLLIN, 1)
             stream.flush(zmq.POLLOUT)
 
 
     def record_ports(self, ports):
         """Record the ports that this kernel is using.
 
         The creator of the Kernel instance must call this methods if they
         want the :meth:`connect_request` method to return the port numbers.
         """
         self._recorded_ports = ports
 
     #---------------------------------------------------------------------------
     # Kernel request handlers
     #---------------------------------------------------------------------------
     
     def _make_metadata(self, other=None):
         """init metadata dict, for execute/apply_reply"""
         new_md = {
             'dependencies_met' : True,
             'engine' : self.ident,
             'started': datetime.now(),
         }
         if other:
             new_md.update(other)
         return new_md
     
     def _publish_execute_input(self, code, parent, execution_count):
         """Publish the code request on the iopub stream."""
 
         self.session.send(self.iopub_socket, u'execute_input',
                             {u'code':code, u'execution_count': execution_count},
                             parent=parent, ident=self._topic('execute_input')
         )
     
     def _publish_status(self, status, parent=None):
         """send status (busy/idle) on IOPub"""
         self.session.send(self.iopub_socket,
                           u'status',
                           {u'execution_state': status},
                           parent=parent or self._parent_header,
                           ident=self._topic('status'),
                           )
     
     def set_parent(self, ident, parent):
         """Set the current parent_header
         
         Side effects (IOPub messages) and replies are associated with
         the request that caused them via the parent_header.
         
         The parent identity is used to route input_request messages
         on the stdin channel.
         """
         self._parent_ident = ident
         self._parent_header = parent
     
     def send_response(self, stream, msg_or_type, content=None, ident=None,
              buffers=None, track=False, header=None, metadata=None):
         """Send a response to the message we're currently processing.
         
         This accepts all the parameters of :meth:`IPython.kernel.zmq.session.Session.send`
         except ``parent``.
         
         This relies on :meth:`set_parent` having been called for the current
         message.
         """
         return self.session.send(stream, msg_or_type, content, self._parent_header,
                                  ident, buffers, track, header, metadata)
     
     def execute_request(self, stream, ident, parent):
         """handle an execute_request"""
         
         try:
             content = parent[u'content']
             code = py3compat.cast_unicode_py2(content[u'code'])
             silent = content[u'silent']
             store_history = content.get(u'store_history', not silent)
             user_expressions = content.get('user_expressions', {})
             allow_stdin = content.get('allow_stdin', False)
         except:
             self.log.error("Got bad msg: ")
             self.log.error("%s", parent)
             return
         
         stop_on_error = content.get('stop_on_error', True)
 
         md = self._make_metadata(parent['metadata'])
         
         # Re-broadcast our input for the benefit of listening clients, and
         # start computing output
         if not silent:
             self.execution_count += 1
             self._publish_execute_input(code, parent, self.execution_count)
         
         reply_content = self.do_execute(code, silent, store_history,
                                         user_expressions, allow_stdin)
 
         # Flush output before sending the reply.
         sys.stdout.flush()
         sys.stderr.flush()
         # FIXME: on rare occasions, the flush doesn't seem to make it to the
         # clients... This seems to mitigate the problem, but we definitely need
         # to better understand what's going on.
         if self._execute_sleep:
             time.sleep(self._execute_sleep)
 
         # Send the reply.
         reply_content = json_clean(reply_content)
         
         md['status'] = reply_content['status']
         if reply_content['status'] == 'error' and \
                         reply_content['ename'] == 'UnmetDependency':
                 md['dependencies_met'] = False
 
         reply_msg = self.session.send(stream, u'execute_reply',
                                       reply_content, parent, metadata=md,
                                       ident=ident)
         
         self.log.debug("%s", reply_msg)
 
         if not silent and reply_msg['content']['status'] == u'error' and stop_on_error:
             self._abort_queues()
 
     def do_execute(self, code, silent, store_history=True,
                    user_expressions=None, allow_stdin=False):
         """Execute user code. Must be overridden by subclasses.
         """
         raise NotImplementedError
 
     def complete_request(self, stream, ident, parent):
         content = parent['content']
         code = content['code']
         cursor_pos = content['cursor_pos']
         
         matches = self.do_complete(code, cursor_pos)
         matches = json_clean(matches)
         completion_msg = self.session.send(stream, 'complete_reply',
                                            matches, parent, ident)
         self.log.debug("%s", completion_msg)
 
     def do_complete(self, code, cursor_pos):
         """Override in subclasses to find completions.
         """
         return {'matches' : [],
                 'cursor_end' : cursor_pos,
                 'cursor_start' : cursor_pos,
                 'metadata' : {},
                 'status' : 'ok'}
 
     def inspect_request(self, stream, ident, parent):
         content = parent['content']
         
         reply_content = self.do_inspect(content['code'], content['cursor_pos'],
                                         content.get('detail_level', 0))
         # Before we send this object over, we scrub it for JSON usage
         reply_content = json_clean(reply_content)
         msg = self.session.send(stream, 'inspect_reply',
                                 reply_content, parent, ident)
         self.log.debug("%s", msg)
 
     def do_inspect(self, code, cursor_pos, detail_level=0):
         """Override in subclasses to allow introspection.
         """
         return {'status': 'ok', 'data':{}, 'metadata':{}, 'found':False}
 
     def history_request(self, stream, ident, parent):
         content = parent['content']
 
         reply_content = self.do_history(**content)
 
         reply_content = json_clean(reply_content)
         msg = self.session.send(stream, 'history_reply',
                                 reply_content, parent, ident)
         self.log.debug("%s", msg)
 
     def do_history(self, hist_access_type, output, raw, session=None, start=None,
                    stop=None, n=None, pattern=None, unique=False):
         """Override in subclasses to access history.
         """
         return {'history': []}
 
     def connect_request(self, stream, ident, parent):
         if self._recorded_ports is not None:
             content = self._recorded_ports.copy()
         else:
             content = {}
         msg = self.session.send(stream, 'connect_reply',
                                 content, parent, ident)
         self.log.debug("%s", msg)
 
     @property
     def kernel_info(self):
         return {
             'protocol_version': release.kernel_protocol_version,
             'implementation': self.implementation,
             'implementation_version': self.implementation_version,
             'language_info': self.language_info,
             'banner': self.banner,
             'help_links': self.help_links,
         }
 
     def kernel_info_request(self, stream, ident, parent):
         msg = self.session.send(stream, 'kernel_info_reply',
                                 self.kernel_info, parent, ident)
         self.log.debug("%s", msg)
 
     def shutdown_request(self, stream, ident, parent):
         content = self.do_shutdown(parent['content']['restart'])
         self.session.send(stream, u'shutdown_reply', content, parent, ident=ident)
         # same content, but different msg_id for broadcasting on IOPub
         self._shutdown_message = self.session.msg(u'shutdown_reply',
                                                   content, parent
         )
 
         self._at_shutdown()
         # call sys.exit after a short delay
         loop = ioloop.IOLoop.instance()
         loop.add_timeout(time.time()+0.1, loop.stop)
 
     def do_shutdown(self, restart):
         """Override in subclasses to do things when the frontend shuts down the
         kernel.
         """
         return {'status': 'ok', 'restart': restart}
     
     def is_complete_request(self, stream, ident, parent):
         content = parent['content']
         code = content['code']
         
         reply_content = self.do_is_complete(code)
         reply_content = json_clean(reply_content)
         reply_msg = self.session.send(stream, 'is_complete_reply',
                                            reply_content, parent, ident)
         self.log.debug("%s", reply_msg)
 
     def do_is_complete(self, code):
         """Override in subclasses to find completions.
         """
         return {'status' : 'unknown',
                 }
 
     #---------------------------------------------------------------------------
     # Engine methods
     #---------------------------------------------------------------------------
 
     def apply_request(self, stream, ident, parent):
         try:
             content = parent[u'content']
             bufs = parent[u'buffers']
             msg_id = parent['header']['msg_id']
         except:
             self.log.error("Got bad msg: %s", parent, exc_info=True)
             return
 
         md = self._make_metadata(parent['metadata'])
 
         reply_content, result_buf = self.do_apply(content, bufs, msg_id, md)
 
         # put 'ok'/'error' status in header, for scheduler introspection:
         md['status'] = reply_content['status']
 
         # flush i/o
         sys.stdout.flush()
         sys.stderr.flush()
         
         self.session.send(stream, u'apply_reply', reply_content,
                     parent=parent, ident=ident,buffers=result_buf, metadata=md)
 
     def do_apply(self, content, bufs, msg_id, reply_metadata):
         """Override in subclasses to support the IPython parallel framework.
         """
         raise NotImplementedError
 
     #---------------------------------------------------------------------------
     # Control messages
     #---------------------------------------------------------------------------
 
     def abort_request(self, stream, ident, parent):
         """abort a specific msg by id"""
         msg_ids = parent['content'].get('msg_ids', None)
         if isinstance(msg_ids, string_types):
             msg_ids = [msg_ids]
         if not msg_ids:
             self._abort_queues()
         for mid in msg_ids:
             self.aborted.add(str(mid))
 
         content = dict(status='ok')
         reply_msg = self.session.send(stream, 'abort_reply', content=content,
                 parent=parent, ident=ident)
         self.log.debug("%s", reply_msg)
 
     def clear_request(self, stream, idents, parent):
         """Clear our namespace."""
         content = self.do_clear()
         self.session.send(stream, 'clear_reply', ident=idents, parent=parent,
                 content = content)
 
     def do_clear(self):
         """Override in subclasses to clear the namespace
         
         This is only required for IPython.parallel.
         """
         raise NotImplementedError
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
 
     def _topic(self, topic):
         """prefixed topic for IOPub messages"""
         if self.int_id >= 0:
             base = "engine.%i" % self.int_id
         else:
             base = "kernel.%s" % self.ident
         
         return py3compat.cast_bytes("%s.%s" % (base, topic))
     
     def _abort_queues(self):
         for stream in self.shell_streams:
             if stream:
                 self._abort_queue(stream)
 
     def _abort_queue(self, stream):
         poller = zmq.Poller()
         poller.register(stream.socket, zmq.POLLIN)
         while True:
             idents,msg = self.session.recv(stream, zmq.NOBLOCK, content=True)
             if msg is None:
                 return
 
             self.log.info("Aborting:")
             self.log.info("%s", msg)
             msg_type = msg['header']['msg_type']
             reply_type = msg_type.split('_')[0] + '_reply'
 
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             reply_msg = self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             self.log.debug("%s", reply_msg)
             # We need to wait a bit for requests to come in. This can probably
             # be set shorter for true asynchronous clients.
             poller.poll(50)
 
 
     def _no_raw_input(self):
         """Raise StdinNotImplentedError if active frontend doesn't support
         stdin."""
         raise StdinNotImplementedError("raw_input was called, but this "
                                        "frontend does not support stdin.") 
     
     def getpass(self, prompt=''):
         """Forward getpass to frontends
         
         Raises
         ------
         StdinNotImplentedError if active frontend doesn't support stdin.
         """
         if not self._allow_stdin:
             raise StdinNotImplementedError(
                 "getpass was called, but this frontend does not support input requests."
             )
         return self._input_request(prompt,
             self._parent_ident,
             self._parent_header,
             password=True,
         )
     
     def raw_input(self, prompt=''):
         """Forward raw_input to frontends
         
         Raises
         ------
         StdinNotImplentedError if active frontend doesn't support stdin.
         """
         if not self._allow_stdin:
             raise StdinNotImplementedError(
                 "raw_input was called, but this frontend does not support input requests."
             )
         return self._input_request(prompt,
             self._parent_ident,
             self._parent_header,
             password=False,
         )
     
     def _input_request(self, prompt, ident, parent, password=False):
         # Flush output before making the request.
         sys.stderr.flush()
         sys.stdout.flush()
         # flush the stdin socket, to purge stale replies
         while True:
             try:
                 self.stdin_socket.recv_multipart(zmq.NOBLOCK)
             except zmq.ZMQError as e:
                 if e.errno == zmq.EAGAIN:
                     break
                 else:
                     raise
         
         # Send the input request.
         content = json_clean(dict(prompt=prompt, password=password))
         self.session.send(self.stdin_socket, u'input_request', content, parent,
                           ident=ident)
 
         # Await a response.
         while True:
             try:
                 ident, reply = self.session.recv(self.stdin_socket, 0)
             except Exception:
                 self.log.warn("Invalid Message:", exc_info=True)
             except KeyboardInterrupt:
                 # re-raise KeyboardInterrupt, to truncate traceback
                 raise KeyboardInterrupt
             else:
                 break
         try:
             value = py3compat.unicode_to_str(reply['content']['value'])
         except:
             self.log.error("Bad input_reply: %s", parent)
             value = ''
         if value == '\x04':
             # EOF
             raise EOFError
         return value
 
     def _at_shutdown(self):
         """Actions taken at shutdown by the kernel, called by python's atexit.
         """
         # io.rprint("Kernel at_shutdown") # dbg
         if self._shutdown_message is not None:
             self.session.send(self.iopub_socket, self._shutdown_message, ident=self._topic('shutdown'))
             self.log.debug("%s", self._shutdown_message)
         [ s.flush(zmq.POLLOUT) for s in self.shell_streams ]