Merge pull request #2882 from takluyver/utils-cleanup

Utils cleanup.

This removes various unused code that was sitting in IPython.utils.

I checked that we don't use these functions and modules at present, but we may want to leave some of them for future use or for extension authors. For the first pass, I've been deliberately quite aggressive about removing things.

IPython/core/magics/code.py

@@ -1,558 +1,559
 """Implementation of code management magic functions.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import inspect
 import io
 import os
 import re
 import sys
 
 # Our own packages
 from IPython.core.error import TryNext, StdinNotImplementedError, UsageError
 from IPython.core.macro import Macro
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.core.oinspect import find_file, find_source_lines
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import py3compat
 from IPython.utils.contexts import preserve_keys
-from IPython.utils.io import file_read
 from IPython.utils.path import get_py_filename, unquote_filename
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
 #-----------------------------------------------------------------------------
 
 # Used for exception handling in magic_edit
 class MacroToEdit(ValueError): pass
 
 ipython_input_pat = re.compile(r"<ipython\-input\-(\d+)-[a-z\d]+>$")
 
 class InteractivelyDefined(Exception):
     """Exception for interactively defined variable in magic_edit"""
     def __init__(self, index):
         self.index = index
 
 
 @magics_class
 class CodeMagics(Magics):
     """Magics related to code management (loading, saving, editing, ...)."""
 
     @line_magic
     def save(self, parameter_s=''):
         """Save a set of lines or a macro to a given filename.
 
         Usage:\\
           %save [options] filename n1-n2 n3-n4 ... n5 .. n6 ...
 
         Options:
 
           -r: use 'raw' input.  By default, the 'processed' history is used,
           so that magics are loaded in their transformed version to valid
           Python.  If this option is given, the raw input as typed as the
           command line is used instead.
           
           -f: force overwrite.  If file exists, %save will prompt for overwrite
           unless -f is given.
 
           -a: append to the file instead of overwriting it.
 
         This function uses the same syntax as %history for input ranges,
         then saves the lines to the filename you specify.
 
         It adds a '.py' extension to the file if you don't do so yourself, and
         it asks for confirmation before overwriting existing files.
 
         If `-r` option is used, the default extension is `.ipy`.
         """
 
         opts,args = self.parse_options(parameter_s,'fra',mode='list')
         if not args:
             raise UsageError('Missing filename.')
         raw = 'r' in opts
         force = 'f' in opts
         append = 'a' in opts
         mode = 'a' if append else 'w'
         ext = u'.ipy' if raw else u'.py'
         fname, codefrom = unquote_filename(args[0]), " ".join(args[1:])
         if not fname.endswith((u'.py',u'.ipy')):
             fname += ext
         file_exists = os.path.isfile(fname)
         if file_exists and not force and not append:
             try:
                 overwrite = self.shell.ask_yes_no('File `%s` exists. Overwrite (y/[N])? ' % fname, default='n')
             except StdinNotImplementedError:
                 print "File `%s` exists. Use `%%save -f %s` to force overwrite" % (fname, parameter_s)
                 return
             if not overwrite :
                 print 'Operation cancelled.'
                 return
         try:
             cmds = self.shell.find_user_code(codefrom,raw)
         except (TypeError, ValueError) as e:
             print e.args[0]
             return
         out = py3compat.cast_unicode(cmds)
         with io.open(fname, mode, encoding="utf-8") as f:
             if not file_exists or not append:
                 f.write(u"# coding: utf-8\n")
             f.write(out)
             # make sure we end on a newline
             if not out.endswith(u'\n'):
                 f.write(u'\n')
         print 'The following commands were written to file `%s`:' % fname
         print cmds
 
     @line_magic
     def pastebin(self, parameter_s=''):
         """Upload code to Github's Gist paste bin, returning the URL.
 
         Usage:\\
           %pastebin [-d "Custom description"] 1-7
 
         The argument can be an input history range, a filename, or the name of a
         string or macro.
 
         Options:
 
           -d: Pass a custom description for the gist. The default will say
               "Pasted from IPython".
         """
         opts, args = self.parse_options(parameter_s, 'd:')
 
         try:
             code = self.shell.find_user_code(args)
         except (ValueError, TypeError) as e:
             print e.args[0]
             return
 
         from urllib2 import urlopen  # Deferred import
         import json
         post_data = json.dumps({
           "description": opts.get('d', "Pasted from IPython"),
           "public": True,
           "files": {
             "file1.py": {
               "content": code
             }
           }
         }).encode('utf-8')
 
         response = urlopen("https://api.github.com/gists", post_data)
         response_data = json.loads(response.read().decode('utf-8'))
         return response_data['html_url']
 
     @line_magic
     def loadpy(self, arg_s):
         """Alias of `%load`
 
         `%loadpy` has gained some flexibility and droped the requirement of a `.py`
         extension. So it has been renamed simply into %load. You can look at
         `%load`'s docstring for more info.
         """
         self.load(arg_s)
 
     @line_magic
     def load(self, arg_s):
         """Load code into the current frontend.
 
         Usage:\\
           %load [options] source
 
           where source can be a filename, URL, input history range or macro
 
         Options:
         --------
           -y : Don't ask confirmation for loading source above 200 000 characters.
 
         This magic command can either take a local filename, a URL, an history
         range (see %history) or a macro as argument, it will prompt for
         confirmation before loading source with more than 200 000 characters, unless
         -y flag is passed or if the frontend does not support raw_input::
 
         %load myscript.py
         %load 7-27
         %load myMacro
         %load http://www.example.com/myscript.py
         """
         opts,args = self.parse_options(arg_s,'y')
         if not args:
             raise UsageError('Missing filename, URL, input history range, '
                              'or macro.')
 
         contents = self.shell.find_user_code(args)
         l = len(contents)
 
         # 200 000 is ~ 2500 full 80 caracter lines
         # so in average, more than 5000 lines
         if l > 200000 and 'y' not in opts:
             try:
                 ans = self.shell.ask_yes_no(("The text you're trying to load seems pretty big"\
                 " (%d characters). Continue (y/[N]) ?" % l), default='n' )
             except StdinNotImplementedError:
                 #asume yes if raw input not implemented
                 ans = True
 
             if ans is False :
                 print 'Operation cancelled.'
                 return
 
         self.shell.set_next_input(contents)
 
     @staticmethod
     def _find_edit_target(shell, args, opts, last_call):
         """Utility method used by magic_edit to find what to edit."""
 
         def make_filename(arg):
             "Make a filename from the given args"
             arg = unquote_filename(arg)
             try:
                 filename = get_py_filename(arg)
             except IOError:
                 # If it ends with .py but doesn't already exist, assume we want
                 # a new file.
                 if arg.endswith('.py'):
                     filename = arg
                 else:
                     filename = None
             return filename
 
         # Set a few locals from the options for convenience:
         opts_prev = 'p' in opts
         opts_raw = 'r' in opts
 
         # custom exceptions
         class DataIsObject(Exception): pass
 
         # Default line number value
         lineno = opts.get('n',None)
 
         if opts_prev:
             args = '_%s' % last_call[0]
             if args not in shell.user_ns:
                 args = last_call[1]
 
         # by default this is done with temp files, except when the given
         # arg is a filename
         use_temp = True
 
         data = ''
 
         # First, see if the arguments should be a filename.
         filename = make_filename(args)
         if filename:
             use_temp = False
         elif args:
             # Mode where user specifies ranges of lines, like in %macro.
             data = shell.extract_input_lines(args, opts_raw)
             if not data:
                 try:
                     # Load the parameter given as a variable. If not a string,
                     # process it as an object instead (below)
 
                     #print '*** args',args,'type',type(args)  # dbg
                     data = eval(args, shell.user_ns)
                     if not isinstance(data, basestring):
                         raise DataIsObject
 
                 except (NameError,SyntaxError):
                     # given argument is not a variable, try as a filename
                     filename = make_filename(args)
                     if filename is None:
                         warn("Argument given (%s) can't be found as a variable "
                              "or as a filename." % args)
                         return (None, None, None)
                     use_temp = False
 
                 except DataIsObject:
                     # macros have a special edit function
                     if isinstance(data, Macro):
                         raise MacroToEdit(data)
 
                     # For objects, try to edit the file where they are defined
                     filename = find_file(data)
                     if filename:
                         if 'fakemodule' in filename.lower() and \
                             inspect.isclass(data):
                             # class created by %edit? Try to find source
                             # by looking for method definitions instead, the
                             # __module__ in those classes is FakeModule.
                             attrs = [getattr(data, aname) for aname in dir(data)]
                             for attr in attrs:
                                 if not inspect.ismethod(attr):
                                     continue
                                 filename = find_file(attr)
                                 if filename and \
                                   'fakemodule' not in filename.lower():
                                     # change the attribute to be the edit
                                     # target instead
                                     data = attr
                                     break
                         
                         m = ipython_input_pat.match(os.path.basename(filename))
                         if m:
                             raise InteractivelyDefined(int(m.groups()[0]))
                         
                         datafile = 1
                     if filename is None:
                         filename = make_filename(args)
                         datafile = 1
                         if filename is not None:
                             # only warn about this if we get a real name
                             warn('Could not find file where `%s` is defined.\n'
                              'Opening a file named `%s`' % (args, filename))
                     # Now, make sure we can actually read the source (if it was
                     # in a temp file it's gone by now).
                     if datafile:
                         if lineno is None:
                             lineno = find_source_lines(data)
                         if lineno is None:
                             filename = make_filename(args)
                             if filename is None:
                                 warn('The file where `%s` was defined '
                                      'cannot be read or found.' % data)
                                 return (None, None, None)
                     use_temp = False
 
         if use_temp:
             filename = shell.mktempfile(data)
             print 'IPython will make a temporary file named:',filename
 
         # use last_call to remember the state of the previous call, but don't
         # let it be clobbered by successive '-p' calls.
         try:
             last_call[0] = shell.displayhook.prompt_count
             if not opts_prev:
                 last_call[1] = args
         except:
             pass
 
 
         return filename, lineno, use_temp
 
     def _edit_macro(self,mname,macro):
         """open an editor with the macro data in a file"""
         filename = self.shell.mktempfile(macro.value)
         self.shell.hooks.editor(filename)
 
         # and make a new macro object, to replace the old one
         mfile = open(filename)
         mvalue = mfile.read()
         mfile.close()
         self.shell.user_ns[mname] = Macro(mvalue)
 
     @skip_doctest
     @line_magic
     def edit(self, parameter_s='',last_call=['','']):
         """Bring up an editor and execute the resulting code.
 
         Usage:
           %edit [options] [args]
 
         %edit runs IPython's editor hook. The default version of this hook is
         set to call the editor specified by your $EDITOR environment variable.
         If this isn't found, it will default to vi under Linux/Unix and to
         notepad under Windows. See the end of this docstring for how to change
         the editor hook.
 
         You can also set the value of this editor via the
         ``TerminalInteractiveShell.editor`` option in your configuration file.
         This is useful if you wish to use a different editor from your typical
         default with IPython (and for Windows users who typically don't set
         environment variables).
 
         This command allows you to conveniently edit multi-line code right in
         your IPython session.
 
         If called without arguments, %edit opens up an empty editor with a
         temporary file and will execute the contents of this file when you
         close it (don't forget to save it!).
 
 
         Options:
 
         -n <number>: open the editor at a specified line number.  By default,
         the IPython editor hook uses the unix syntax 'editor +N filename', but
         you can configure this by providing your own modified hook if your
         favorite editor supports line-number specifications with a different
         syntax.
 
         -p: this will call the editor with the same data as the previous time
         it was used, regardless of how long ago (in your current session) it
         was.
 
         -r: use 'raw' input.  This option only applies to input taken from the
         user's history.  By default, the 'processed' history is used, so that
         magics are loaded in their transformed version to valid Python.  If
         this option is given, the raw input as typed as the command line is
         used instead.  When you exit the editor, it will be executed by
         IPython's own processor.
 
         -x: do not execute the edited code immediately upon exit. This is
         mainly useful if you are editing programs which need to be called with
         command line arguments, which you can then do using %run.
 
 
         Arguments:
 
         If arguments are given, the following possibilities exist:
 
         - If the argument is a filename, IPython will load that into the
           editor. It will execute its contents with execfile() when you exit,
           loading any code in the file into your interactive namespace.
 
         - The arguments are ranges of input history,  e.g. "7 ~1/4-6".
           The syntax is the same as in the %history magic.
 
         - If the argument is a string variable, its contents are loaded
           into the editor. You can thus edit any string which contains
           python code (including the result of previous edits).
 
         - If the argument is the name of an object (other than a string),
           IPython will try to locate the file where it was defined and open the
           editor at the point where it is defined. You can use `%edit function`
           to load an editor exactly at the point where 'function' is defined,
           edit it and have the file be executed automatically.
 
         - If the object is a macro (see %macro for details), this opens up your
           specified editor with a temporary file containing the macro's data.
           Upon exit, the macro is reloaded with the contents of the file.
 
         Note: opening at an exact line is only supported under Unix, and some
         editors (like kedit and gedit up to Gnome 2.8) do not understand the
         '+NUMBER' parameter necessary for this feature. Good editors like
         (X)Emacs, vi, jed, pico and joe all do.
 
         After executing your code, %edit will return as output the code you
         typed in the editor (except when it was an existing file). This way
         you can reload the code in further invocations of %edit as a variable,
         via _<NUMBER> or Out[<NUMBER>], where <NUMBER> is the prompt number of
         the output.
 
         Note that %edit is also available through the alias %ed.
 
         This is an example of creating a simple function inside the editor and
         then modifying it. First, start up the editor::
 
           In [1]: edit
           Editing... done. Executing edited code...
           Out[1]: 'def foo():\\n    print "foo() was defined in an editing
           session"\\n'
 
         We can then call the function foo()::
 
           In [2]: foo()
           foo() was defined in an editing session
 
         Now we edit foo.  IPython automatically loads the editor with the
         (temporary) file where foo() was previously defined::
 
           In [3]: edit foo
           Editing... done. Executing edited code...
 
         And if we call foo() again we get the modified version::
 
           In [4]: foo()
           foo() has now been changed!
 
         Here is an example of how to edit a code snippet successive
         times. First we call the editor::
 
           In [5]: edit
           Editing... done. Executing edited code...
           hello
           Out[5]: "print 'hello'\\n"
 
         Now we call it again with the previous output (stored in _)::
 
           In [6]: edit _
           Editing... done. Executing edited code...
           hello world
           Out[6]: "print 'hello world'\\n"
 
         Now we call it with the output #8 (stored in _8, also as Out[8])::
 
           In [7]: edit _8
           Editing... done. Executing edited code...
           hello again
           Out[7]: "print 'hello again'\\n"
 
 
         Changing the default editor hook:
 
         If you wish to write your own editor hook, you can put it in a
         configuration file which you load at startup time.  The default hook
         is defined in the IPython.core.hooks module, and you can use that as a
         starting example for further modifications.  That file also has
         general instructions on how to set a new hook for use once you've
         defined it."""
         opts,args = self.parse_options(parameter_s,'prxn:')
 
         try:
             filename, lineno, is_temp = self._find_edit_target(self.shell, 
                                                        args, opts, last_call)
         except MacroToEdit as e:
             self._edit_macro(args, e.args[0])
             return
         except InteractivelyDefined as e:
             print "Editing In[%i]" % e.index
             args = str(e.index)
             filename, lineno, is_temp = self._find_edit_target(self.shell, 
                                                        args, opts, last_call)
         if filename is None:
             # nothing was found, warnings have already been issued,
             # just give up.
             return
 
         # do actual editing here
         print 'Editing...',
         sys.stdout.flush()
         try:
             # Quote filenames that may have spaces in them
             if ' ' in filename:
                 filename = "'%s'" % filename
             self.shell.hooks.editor(filename,lineno)
         except TryNext:
             warn('Could not open editor')
             return
 
         # XXX TODO: should this be generalized for all string vars?
         # For now, this is special-cased to blocks created by cpaste
         if args.strip() == 'pasted_block':
-            self.shell.user_ns['pasted_block'] = file_read(filename)
+            with open(filename, 'r') as f:
+                self.shell.user_ns['pasted_block'] = f.read()
 
         if 'x' in opts:  # -x prevents actual execution
             print
         else:
             print 'done. Executing edited code...'
             with preserve_keys(self.shell.user_ns, '__file__'):
                 if not is_temp:
                     self.shell.user_ns['__file__'] = filename
                 if 'r' in opts:    # Untranslated IPython code
-                    self.shell.run_cell(file_read(filename),
-                                        store_history=False)
+                    with open(filename, 'r') as f:
+                        source = f.read()
+                    self.shell.run_cell(source, store_history=False)
                 else:
                     self.shell.safe_execfile(filename, self.shell.user_ns,
                                              self.shell.user_ns)
 
         if is_temp:
             try:
                 return open(filename).read()
             except IOError as msg:
                 if msg.filename == filename:
                     warn('File not found. Did you forget to save?')
                     return
                 else:
                     self.shell.showtraceback()

IPython/core/magics/osm.py

@@ -1,726 +1,726
 """Implementation of magic functions for interaction with the OS.
 
 Note: this module is named 'osm' instead of 'os' to avoid a collision with the
 builtin.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import io
 import os
 import re
 import sys
 from pprint import pformat
 
 # Our own packages
 from IPython.core import magic_arguments
 from IPython.core import oinspect
 from IPython.core import page
 from IPython.core.error import UsageError
 from IPython.core.magic import  (
     Magics, compress_dhist, magics_class, line_magic, cell_magic, line_cell_magic
 )
 from IPython.testing.skipdoctest import skip_doctest
-from IPython.utils.io import nlprint
 from IPython.utils.openpy import source_to_unicode
 from IPython.utils.path import unquote_filename
 from IPython.utils.process import abbrev_cwd
 from IPython.utils.terminal import set_term_title
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
 #-----------------------------------------------------------------------------
 @magics_class
 class OSMagics(Magics):
     """Magics to interact with the underlying OS (shell-type functionality).
     """
 
     @skip_doctest
     @line_magic
     def alias(self, parameter_s=''):
         """Define an alias for a system command.
 
         '%alias alias_name cmd' defines 'alias_name' as an alias for 'cmd'
 
         Then, typing 'alias_name params' will execute the system command 'cmd
         params' (from your underlying operating system).
 
         Aliases have lower precedence than magic functions and Python normal
         variables, so if 'foo' is both a Python variable and an alias, the
         alias can not be executed until 'del foo' removes the Python variable.
 
         You can use the %l specifier in an alias definition to represent the
         whole line when the alias is called.  For example::
 
           In [2]: alias bracket echo "Input in brackets: <%l>"
           In [3]: bracket hello world
           Input in brackets: <hello world>
 
         You can also define aliases with parameters using %s specifiers (one
         per parameter)::
 
           In [1]: alias parts echo first %s second %s
           In [2]: %parts A B
           first A second B
           In [3]: %parts A
           Incorrect number of arguments: 2 expected.
           parts is an alias to: 'echo first %s second %s'
 
         Note that %l and %s are mutually exclusive.  You can only use one or
         the other in your aliases.
 
         Aliases expand Python variables just like system calls using ! or !!
         do: all expressions prefixed with '$' get expanded.  For details of
         the semantic rules, see PEP-215:
         http://www.python.org/peps/pep-0215.html.  This is the library used by
         IPython for variable expansion.  If you want to access a true shell
         variable, an extra $ is necessary to prevent its expansion by
         IPython::
 
           In [6]: alias show echo
           In [7]: PATH='A Python string'
           In [8]: show $PATH
           A Python string
           In [9]: show $$PATH
           /usr/local/lf9560/bin:/usr/local/intel/compiler70/ia32/bin:...
 
         You can use the alias facility to acess all of $PATH.  See the %rehash
         and %rehashx functions, which automatically create aliases for the
         contents of your $PATH.
 
         If called with no parameters, %alias prints the current alias table."""
 
         par = parameter_s.strip()
         if not par:
             aliases = sorted(self.shell.alias_manager.aliases)
             # stored = self.shell.db.get('stored_aliases', {} )
             # for k, v in stored:
             #     atab.append(k, v[0])
 
             print "Total number of aliases:", len(aliases)
             sys.stdout.flush()
             return aliases
 
         # Now try to define a new one
         try:
             alias,cmd = par.split(None, 1)
         except:
             print oinspect.getdoc(self.alias)
         else:
             self.shell.alias_manager.soft_define_alias(alias, cmd)
     # end magic_alias
 
     @line_magic
     def unalias(self, parameter_s=''):
         """Remove an alias"""
 
         aname = parameter_s.strip()
         self.shell.alias_manager.undefine_alias(aname)
         stored = self.shell.db.get('stored_aliases', {} )
         if aname in stored:
             print "Removing %stored alias",aname
             del stored[aname]
             self.shell.db['stored_aliases'] = stored
 
     @line_magic
     def rehashx(self, parameter_s=''):
         """Update the alias table with all executable files in $PATH.
 
         This version explicitly checks that every entry in $PATH is a file
         with execute access (os.X_OK), so it is much slower than %rehash.
 
         Under Windows, it checks executability as a match against a
         '|'-separated string of extensions, stored in the IPython config
         variable win_exec_ext.  This defaults to 'exe|com|bat'.
 
         This function also resets the root module cache of module completer,
         used on slow filesystems.
         """
         from IPython.core.alias import InvalidAliasError
 
         # for the benefit of module completer in ipy_completers.py
         del self.shell.db['rootmodules']
 
         path = [os.path.abspath(os.path.expanduser(p)) for p in
             os.environ.get('PATH','').split(os.pathsep)]
         path = filter(os.path.isdir,path)
 
         syscmdlist = []
         # Now define isexec in a cross platform manner.
         if os.name == 'posix':
             isexec = lambda fname:os.path.isfile(fname) and \
                      os.access(fname,os.X_OK)
         else:
             try:
                 winext = os.environ['pathext'].replace(';','|').replace('.','')
             except KeyError:
                 winext = 'exe|com|bat|py'
             if 'py' not in winext:
                 winext += '|py'
             execre = re.compile(r'(.*)\.(%s)$' % winext,re.IGNORECASE)
             isexec = lambda fname:os.path.isfile(fname) and execre.match(fname)
         savedir = os.getcwdu()
 
         # Now walk the paths looking for executables to alias.
         try:
             # write the whole loop for posix/Windows so we don't have an if in
             # the innermost part
             if os.name == 'posix':
                 for pdir in path:
                     os.chdir(pdir)
                     for ff in os.listdir(pdir):
                         if isexec(ff):
                             try:
                                 # Removes dots from the name since ipython
                                 # will assume names with dots to be python.
                                 self.shell.alias_manager.define_alias(
                                     ff.replace('.',''), ff)
                             except InvalidAliasError:
                                 pass
                             else:
                                 syscmdlist.append(ff)
             else:
                 no_alias = self.shell.alias_manager.no_alias
                 for pdir in path:
                     os.chdir(pdir)
                     for ff in os.listdir(pdir):
                         base, ext = os.path.splitext(ff)
                         if isexec(ff) and base.lower() not in no_alias:
                             if ext.lower() == '.exe':
                                 ff = base
                                 try:
                                     # Removes dots from the name since ipython
                                     # will assume names with dots to be python.
                                     self.shell.alias_manager.define_alias(
                                         base.lower().replace('.',''), ff)
                                 except InvalidAliasError:
                                     pass
                                 syscmdlist.append(ff)
             self.shell.db['syscmdlist'] = syscmdlist
         finally:
             os.chdir(savedir)
 
     @skip_doctest
     @line_magic
     def pwd(self, parameter_s=''):
         """Return the current working directory path.
 
         Examples
         --------
         ::
 
           In [9]: pwd
           Out[9]: '/home/tsuser/sprint/ipython'
         """
         return os.getcwdu()
 
     @skip_doctest
     @line_magic
     def cd(self, parameter_s=''):
         """Change the current working directory.
 
         This command automatically maintains an internal list of directories
         you visit during your IPython session, in the variable _dh. The
         command %dhist shows this history nicely formatted. You can also
         do 'cd -<tab>' to see directory history conveniently.
 
         Usage:
 
           cd 'dir': changes to directory 'dir'.
 
           cd -: changes to the last visited directory.
 
           cd -<n>: changes to the n-th directory in the directory history.
 
           cd --foo: change to directory that matches 'foo' in history
 
           cd -b <bookmark_name>: jump to a bookmark set by %bookmark
              (note: cd <bookmark_name> is enough if there is no
               directory <bookmark_name>, but a bookmark with the name exists.)
               'cd -b <tab>' allows you to tab-complete bookmark names.
 
         Options:
 
         -q: quiet.  Do not print the working directory after the cd command is
         executed.  By default IPython's cd command does print this directory,
         since the default prompts do not display path information.
 
         Note that !cd doesn't work for this purpose because the shell where
         !command runs is immediately discarded after executing 'command'.
 
         Examples
         --------
         ::
 
           In [10]: cd parent/child
           /home/tsuser/parent/child
         """
 
         oldcwd = os.getcwdu()
         numcd = re.match(r'(-)(\d+)$',parameter_s)
         # jump in directory history by number
         if numcd:
             nn = int(numcd.group(2))
             try:
                 ps = self.shell.user_ns['_dh'][nn]
             except IndexError:
                 print 'The requested directory does not exist in history.'
                 return
             else:
                 opts = {}
         elif parameter_s.startswith('--'):
             ps = None
             fallback = None
             pat = parameter_s[2:]
             dh = self.shell.user_ns['_dh']
             # first search only by basename (last component)
             for ent in reversed(dh):
                 if pat in os.path.basename(ent) and os.path.isdir(ent):
                     ps = ent
                     break
 
                 if fallback is None and pat in ent and os.path.isdir(ent):
                     fallback = ent
 
             # if we have no last part match, pick the first full path match
             if ps is None:
                 ps = fallback
 
             if ps is None:
                 print "No matching entry in directory history"
                 return
             else:
                 opts = {}
 
 
         else:
             #turn all non-space-escaping backslashes to slashes,
             # for c:\windows\directory\names\
             parameter_s = re.sub(r'\\(?! )','/', parameter_s)
             opts,ps = self.parse_options(parameter_s,'qb',mode='string')
         # jump to previous
         if ps == '-':
             try:
                 ps = self.shell.user_ns['_dh'][-2]
             except IndexError:
                 raise UsageError('%cd -: No previous directory to change to.')
         # jump to bookmark if needed
         else:
             if not os.path.isdir(ps) or 'b' in opts:
                 bkms = self.shell.db.get('bookmarks', {})
 
                 if ps in bkms:
                     target = bkms[ps]
                     print '(bookmark:%s) -> %s' % (ps, target)
                     ps = target
                 else:
                     if 'b' in opts:
                         raise UsageError("Bookmark '%s' not found.  "
                               "Use '%%bookmark -l' to see your bookmarks." % ps)
 
         # strip extra quotes on Windows, because os.chdir doesn't like them
         ps = unquote_filename(ps)
         # at this point ps should point to the target dir
         if ps:
             try:
                 os.chdir(os.path.expanduser(ps))
                 if hasattr(self.shell, 'term_title') and self.shell.term_title:
                     set_term_title('IPython: ' + abbrev_cwd())
             except OSError:
                 print sys.exc_info()[1]
             else:
                 cwd = os.getcwdu()
                 dhist = self.shell.user_ns['_dh']
                 if oldcwd != cwd:
                     dhist.append(cwd)
                     self.shell.db['dhist'] = compress_dhist(dhist)[-100:]
 
         else:
             os.chdir(self.shell.home_dir)
             if hasattr(self.shell, 'term_title') and self.shell.term_title:
                 set_term_title('IPython: ' + '~')
             cwd = os.getcwdu()
             dhist = self.shell.user_ns['_dh']
 
             if oldcwd != cwd:
                 dhist.append(cwd)
                 self.shell.db['dhist'] = compress_dhist(dhist)[-100:]
         if not 'q' in opts and self.shell.user_ns['_dh']:
             print self.shell.user_ns['_dh'][-1]
 
 
     @line_magic
     def env(self, parameter_s=''):
         """List environment variables."""
 
         return dict(os.environ)
 
     @line_magic
     def pushd(self, parameter_s=''):
         """Place the current dir on stack and change directory.
 
         Usage:\\
           %pushd ['dirname']
         """
 
         dir_s = self.shell.dir_stack
         tgt = os.path.expanduser(unquote_filename(parameter_s))
         cwd = os.getcwdu().replace(self.shell.home_dir,'~')
         if tgt:
             self.cd(parameter_s)
         dir_s.insert(0,cwd)
         return self.shell.magic('dirs')
 
     @line_magic
     def popd(self, parameter_s=''):
         """Change to directory popped off the top of the stack.
         """
         if not self.shell.dir_stack:
             raise UsageError("%popd on empty stack")
         top = self.shell.dir_stack.pop(0)
         self.cd(top)
         print "popd ->",top
 
     @line_magic
     def dirs(self, parameter_s=''):
         """Return the current directory stack."""
 
         return self.shell.dir_stack
 
     @line_magic
     def dhist(self, parameter_s=''):
         """Print your history of visited directories.
 
         %dhist       -> print full history\\
         %dhist n     -> print last n entries only\\
-        %dhist n1 n2 -> print entries between n1 and n2 (n1 not included)\\
+        %dhist n1 n2 -> print entries between n1 and n2 (n2 not included)\\
 
         This history is automatically maintained by the %cd command, and
         always available as the global list variable _dh. You can use %cd -<n>
         to go to directory number <n>.
 
         Note that most of time, you should view directory history by entering
         cd -<TAB>.
 
         """
 
         dh = self.shell.user_ns['_dh']
         if parameter_s:
             try:
                 args = map(int,parameter_s.split())
             except:
                 self.arg_err(self.dhist)
                 return
             if len(args) == 1:
                 ini,fin = max(len(dh)-(args[0]),0),len(dh)
             elif len(args) == 2:
                 ini,fin = args
+                fin = min(fin, len(dh))
             else:
                 self.arg_err(self.dhist)
                 return
         else:
             ini,fin = 0,len(dh)
-        nlprint(dh,
-                header = 'Directory history (kept in _dh)',
-                start=ini,stop=fin)
+        print 'Directory history (kept in _dh)'
+        for i in range(ini, fin):
+            print "%d: %s" % (i, dh[i])
 
     @skip_doctest
     @line_magic
     def sc(self, parameter_s=''):
         """Shell capture - run shell command and capture output (DEPRECATED use !).
 
         DEPRECATED. Suboptimal, retained for backwards compatibility.
 
         You should use the form 'var = !command' instead. Example:
 
          "%sc -l myfiles = ls ~" should now be written as
 
          "myfiles = !ls ~"
 
         myfiles.s, myfiles.l and myfiles.n still apply as documented
         below.
 
         --
         %sc [options] varname=command
 
         IPython will run the given command using commands.getoutput(), and
         will then update the user's interactive namespace with a variable
         called varname, containing the value of the call.  Your command can
         contain shell wildcards, pipes, etc.
 
         The '=' sign in the syntax is mandatory, and the variable name you
         supply must follow Python's standard conventions for valid names.
 
         (A special format without variable name exists for internal use)
 
         Options:
 
           -l: list output.  Split the output on newlines into a list before
           assigning it to the given variable.  By default the output is stored
           as a single string.
 
           -v: verbose.  Print the contents of the variable.
 
         In most cases you should not need to split as a list, because the
         returned value is a special type of string which can automatically
         provide its contents either as a list (split on newlines) or as a
         space-separated string.  These are convenient, respectively, either
         for sequential processing or to be passed to a shell command.
 
         For example::
 
             # Capture into variable a
             In [1]: sc a=ls *py
 
             # a is a string with embedded newlines
             In [2]: a
             Out[2]: 'setup.py\\nwin32_manual_post_install.py'
 
             # which can be seen as a list:
             In [3]: a.l
             Out[3]: ['setup.py', 'win32_manual_post_install.py']
 
             # or as a whitespace-separated string:
             In [4]: a.s
             Out[4]: 'setup.py win32_manual_post_install.py'
 
             # a.s is useful to pass as a single command line:
             In [5]: !wc -l $a.s
               146 setup.py
               130 win32_manual_post_install.py
               276 total
 
             # while the list form is useful to loop over:
             In [6]: for f in a.l:
               ...:      !wc -l $f
               ...:
             146 setup.py
             130 win32_manual_post_install.py
 
         Similarly, the lists returned by the -l option are also special, in
         the sense that you can equally invoke the .s attribute on them to
         automatically get a whitespace-separated string from their contents::
 
             In [7]: sc -l b=ls *py
 
             In [8]: b
             Out[8]: ['setup.py', 'win32_manual_post_install.py']
 
             In [9]: b.s
             Out[9]: 'setup.py win32_manual_post_install.py'
 
         In summary, both the lists and strings used for output capture have
         the following special attributes::
 
             .l (or .list) : value as list.
             .n (or .nlstr): value as newline-separated string.
             .s (or .spstr): value as space-separated string.
         """
 
         opts,args = self.parse_options(parameter_s, 'lv')
         # Try to get a variable name and command to run
         try:
             # the variable name must be obtained from the parse_options
             # output, which uses shlex.split to strip options out.
             var,_ = args.split('=', 1)
             var = var.strip()
             # But the command has to be extracted from the original input
             # parameter_s, not on what parse_options returns, to avoid the
             # quote stripping which shlex.split performs on it.
             _,cmd = parameter_s.split('=', 1)
         except ValueError:
             var,cmd = '',''
         # If all looks ok, proceed
         split = 'l' in opts
         out = self.shell.getoutput(cmd, split=split)
         if 'v' in opts:
             print '%s ==\n%s' % (var, pformat(out))
         if var:
             self.shell.user_ns.update({var:out})
         else:
             return out
 
     @line_cell_magic
     def sx(self, line='', cell=None):
         """Shell execute - run shell command and capture output (!! is short-hand).
 
         %sx command
 
         IPython will run the given command using commands.getoutput(), and
         return the result formatted as a list (split on '\\n').  Since the
         output is _returned_, it will be stored in ipython's regular output
         cache Out[N] and in the '_N' automatic variables.
 
         Notes:
 
         1) If an input line begins with '!!', then %sx is automatically
         invoked.  That is, while::
 
           !ls
 
         causes ipython to simply issue system('ls'), typing::
 
           !!ls
 
         is a shorthand equivalent to::
 
           %sx ls
 
         2) %sx differs from %sc in that %sx automatically splits into a list,
         like '%sc -l'.  The reason for this is to make it as easy as possible
         to process line-oriented shell output via further python commands.
         %sc is meant to provide much finer control, but requires more
         typing.
 
         3) Just like %sc -l, this is a list with special attributes:
         ::
 
           .l (or .list) : value as list.
           .n (or .nlstr): value as newline-separated string.
           .s (or .spstr): value as whitespace-separated string.
 
         This is very useful when trying to use such lists as arguments to
         system commands."""
         
         if cell is None:
             # line magic
             return self.shell.getoutput(line)
         else:
             opts,args = self.parse_options(line, '', 'out=')
             output = self.shell.getoutput(cell)
             out_name = opts.get('out', opts.get('o'))
             if out_name:
                 self.shell.user_ns[out_name] = output
             else:
                 return output
 
     system = line_cell_magic('system')(sx)
     bang = cell_magic('!')(sx)
 
     @line_magic
     def bookmark(self, parameter_s=''):
         """Manage IPython's bookmark system.
 
         %bookmark <name>       - set bookmark to current dir
         %bookmark <name> <dir> - set bookmark to <dir>
         %bookmark -l           - list all bookmarks
         %bookmark -d <name>    - remove bookmark
         %bookmark -r           - remove all bookmarks
 
         You can later on access a bookmarked folder with::
 
           %cd -b <name>
 
         or simply '%cd <name>' if there is no directory called <name> AND
         there is such a bookmark defined.
 
         Your bookmarks persist through IPython sessions, but they are
         associated with each profile."""
 
         opts,args = self.parse_options(parameter_s,'drl',mode='list')
         if len(args) > 2:
             raise UsageError("%bookmark: too many arguments")
 
         bkms = self.shell.db.get('bookmarks',{})
 
         if 'd' in opts:
             try:
                 todel = args[0]
             except IndexError:
                 raise UsageError(
                     "%bookmark -d: must provide a bookmark to delete")
             else:
                 try:
                     del bkms[todel]
                 except KeyError:
                     raise UsageError(
                         "%%bookmark -d: Can't delete bookmark '%s'" % todel)
 
         elif 'r' in opts:
             bkms = {}
         elif 'l' in opts:
             bks = bkms.keys()
             bks.sort()
             if bks:
                 size = max(map(len, bks))
             else:
                 size = 0
             fmt = '%-'+str(size)+'s -> %s'
             print 'Current bookmarks:'
             for bk in bks:
                 print fmt % (bk, bkms[bk])
         else:
             if not args:
                 raise UsageError("%bookmark: You must specify the bookmark name")
             elif len(args)==1:
                 bkms[args[0]] = os.getcwdu()
             elif len(args)==2:
                 bkms[args[0]] = args[1]
         self.shell.db['bookmarks'] = bkms
 
     @line_magic
     def pycat(self, parameter_s=''):
         """Show a syntax-highlighted file through a pager.
 
         This magic is similar to the cat utility, but it will assume the file
         to be Python source and will show it with syntax highlighting.
 
         This magic command can either take a local filename, an url,
         an history range (see %history) or a macro as argument ::
 
         %pycat myscript.py
         %pycat 7-27
         %pycat myMacro
         %pycat http://www.example.com/myscript.py
         """
         if not parameter_s:
             raise UsageError('Missing filename, URL, input history range, '
                              'or macro.')
 
         try :
             cont = self.shell.find_user_code(parameter_s, skip_encoding_cookie=False)
         except (ValueError, IOError):
             print "Error: no such file, variable, URL, history range or macro"
             return
 
         page.page(self.shell.pycolorize(source_to_unicode(cont)))
 
     @magic_arguments.magic_arguments()
     @magic_arguments.argument(
         '-a', '--amend', action='store_true', default=False,
         help='Open file for amending if it exists'
     )
     @magic_arguments.argument(
         'filename', type=unicode,
         help='file to write'
     )
     @cell_magic
     def file(self, line, cell):
         """Write the contents of the cell to a file.
         
         For frontends that do not support stdin (Notebook), -f is implied.
         """
         args = magic_arguments.parse_argstring(self.file, line)
         filename = unquote_filename(args.filename)
         
         if os.path.exists(filename):
             if args.amend:
                 print "Amending to %s" % filename
             else:
                 print "Overwriting %s" % filename
         else:
             print "Writing %s" % filename
         
         mode = 'a' if args.amend else 'w'
         with io.open(filename, mode, encoding='utf-8') as f:
             f.write(cell)

IPython/core/ultratb.py

@@ -1,1246 +1,1246
 # -*- coding: utf-8 -*-
 """
 ultratb.py -- Spice up your tracebacks!
 
 * ColorTB
 I've always found it a bit hard to visually parse tracebacks in Python.  The
 ColorTB class is a solution to that problem.  It colors the different parts of a
 traceback in a manner similar to what you would expect from a syntax-highlighting
 text editor.
 
 Installation instructions for ColorTB:
     import sys,ultratb
     sys.excepthook = ultratb.ColorTB()
 
 * VerboseTB
 I've also included a port of Ka-Ping Yee's "cgitb.py" that produces all kinds
 of useful info when a traceback occurs.  Ping originally had it spit out HTML
 and intended it for CGI programmers, but why should they have all the fun?  I
 altered it to spit out colored text to the terminal.  It's a bit overwhelming,
 but kind of neat, and maybe useful for long-running programs that you believe
 are bug-free.  If a crash *does* occur in that type of program you want details.
 Give it a shot--you'll love it or you'll hate it.
 
 Note:
 
   The Verbose mode prints the variables currently visible where the exception
   happened (shortening their strings if too long). This can potentially be
   very slow, if you happen to have a huge data structure whose string
   representation is complex to compute. Your computer may appear to freeze for
   a while with cpu usage at 100%. If this occurs, you can cancel the traceback
   with Ctrl-C (maybe hitting it more than once).
 
   If you encounter this kind of situation often, you may want to use the
   Verbose_novars mode instead of the regular Verbose, which avoids formatting
   variables (but otherwise includes the information and context given by
   Verbose).
 
 
 Installation instructions for ColorTB:
     import sys,ultratb
     sys.excepthook = ultratb.VerboseTB()
 
 Note:  Much of the code in this module was lifted verbatim from the standard
 library module 'traceback.py' and Ka-Ping Yee's 'cgitb.py'.
 
 * Color schemes
 The colors are defined in the class TBTools through the use of the
 ColorSchemeTable class. Currently the following exist:
 
   - NoColor: allows all of this module to be used in any terminal (the color
   escapes are just dummy blank strings).
 
   - Linux: is meant to look good in a terminal like the Linux console (black
   or very dark background).
 
   - LightBG: similar to Linux but swaps dark/light colors to be more readable
   in light background terminals.
 
 You can implement other color schemes easily, the syntax is fairly
 self-explanatory. Please send back new schemes you develop to the author for
 possible inclusion in future releases.
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.core.ultratb
    :parts: 3
 """
 
 #*****************************************************************************
 #       Copyright (C) 2001 Nathaniel Gray <[e-mail]>
 #       Copyright (C) 2001-2004 Fernando Perez <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 from __future__ import unicode_literals
 
 import inspect
 import keyword
 import linecache
 import os
 import pydoc
 import re
 import sys
 import time
 import tokenize
 import traceback
 import types
 
 try:                           # Python 2
     generate_tokens = tokenize.generate_tokens
 except AttributeError:         # Python 3
     generate_tokens = tokenize.tokenize
 
 # For purposes of monkeypatching inspect to fix a bug in it.
 from inspect import getsourcefile, getfile, getmodule,\
      ismodule, isclass, ismethod, isfunction, istraceback, isframe, iscode
 
 # IPython's own modules
 # Modified pdb which doesn't damage IPython's readline handling
 from IPython.core import debugger, ipapi
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.excolors import exception_colors
 from IPython.utils import PyColorize
 from IPython.utils import io
+from IPython.utils import openpy
 from IPython.utils import path as util_path
 from IPython.utils import py3compat
-from IPython.utils import pyfile
 from IPython.utils import ulinecache
 from IPython.utils.data import uniq_stable
 from IPython.utils.warn import info, error
 
 # Globals
 # amount of space to put line numbers before verbose tracebacks
 INDENT_SIZE = 8
 
 # Default color scheme.  This is used, for example, by the traceback
 # formatter.  When running in an actual IPython instance, the user's rc.colors
 # value is used, but havinga module global makes this functionality available
 # to users of ultratb who are NOT running inside ipython.
 DEFAULT_SCHEME = 'NoColor'
 
 #---------------------------------------------------------------------------
 # Code begins
 
 # Utility functions
 def inspect_error():
     """Print a message about internal inspect errors.
 
     These are unfortunately quite common."""
 
     error('Internal Python error in the inspect module.\n'
           'Below is the traceback from this internal error.\n')
 
 # This function is a monkeypatch we apply to the Python inspect module. We have
 # now found when it's needed (see discussion on issue gh-1456), and we have a
 # test case (IPython.core.tests.test_ultratb.ChangedPyFileTest) that fails if
 # the monkeypatch is not applied. TK, Aug 2012.
 def findsource(object):
     """Return the entire source file and starting line number for an object.
 
     The argument may be a module, class, method, function, traceback, frame,
     or code object.  The source code is returned as a list of all the lines
     in the file and the line number indexes a line in that list.  An IOError
     is raised if the source code cannot be retrieved.
 
     FIXED version with which we monkeypatch the stdlib to work around a bug."""
 
     file = getsourcefile(object) or getfile(object)
     # If the object is a frame, then trying to get the globals dict from its
     # module won't work. Instead, the frame object itself has the globals
     # dictionary.
     globals_dict = None
     if inspect.isframe(object):
         # XXX: can this ever be false?
         globals_dict = object.f_globals
     else:
         module = getmodule(object, file)
         if module:
             globals_dict = module.__dict__
     lines = linecache.getlines(file, globals_dict)
     if not lines:
         raise IOError('could not get source code')
 
     if ismodule(object):
         return lines, 0
 
     if isclass(object):
         name = object.__name__
         pat = re.compile(r'^(\s*)class\s*' + name + r'\b')
         # make some effort to find the best matching class definition:
         # use the one with the least indentation, which is the one
         # that's most probably not inside a function definition.
         candidates = []
         for i in range(len(lines)):
             match = pat.match(lines[i])
             if match:
                 # if it's at toplevel, it's already the best one
                 if lines[i][0] == 'c':
                     return lines, i
                 # else add whitespace to candidate list
                 candidates.append((match.group(1), i))
         if candidates:
             # this will sort by whitespace, and by line number,
             # less whitespace first
             candidates.sort()
             return lines, candidates[0][1]
         else:
             raise IOError('could not find class definition')
 
     if ismethod(object):
         object = object.im_func
     if isfunction(object):
         object = object.func_code
     if istraceback(object):
         object = object.tb_frame
     if isframe(object):
         object = object.f_code
     if iscode(object):
         if not hasattr(object, 'co_firstlineno'):
             raise IOError('could not find function definition')
         pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
         pmatch = pat.match
         # fperez - fix: sometimes, co_firstlineno can give a number larger than
         # the length of lines, which causes an error.  Safeguard against that.
         lnum = min(object.co_firstlineno,len(lines))-1
         while lnum > 0:
             if pmatch(lines[lnum]): break
             lnum -= 1
 
         return lines, lnum
     raise IOError('could not find code object')
 
 # Monkeypatch inspect to apply our bugfix.  This code only works with Python >= 2.5
 inspect.findsource = findsource
 
 def fix_frame_records_filenames(records):
     """Try to fix the filenames in each record from inspect.getinnerframes().
 
     Particularly, modules loaded from within zip files have useless filenames
     attached to their code object, and inspect.getinnerframes() just uses it.
     """
     fixed_records = []
     for frame, filename, line_no, func_name, lines, index in records:
         # Look inside the frame's globals dictionary for __file__, which should
         # be better.
         better_fn = frame.f_globals.get('__file__', None)
         if isinstance(better_fn, str):
             # Check the type just in case someone did something weird with
             # __file__. It might also be None if the error occurred during
             # import.
             filename = better_fn
         fixed_records.append((frame, filename, line_no, func_name, lines, index))
     return fixed_records
 
 
 def _fixed_getinnerframes(etb, context=1,tb_offset=0):
     LNUM_POS, LINES_POS, INDEX_POS =  2, 4, 5
 
     records  = fix_frame_records_filenames(inspect.getinnerframes(etb, context))
 
     # If the error is at the console, don't build any context, since it would
     # otherwise produce 5 blank lines printed out (there is no file at the
     # console)
     rec_check = records[tb_offset:]
     try:
         rname = rec_check[0][1]
         if rname == '<ipython console>' or rname.endswith('<string>'):
             return rec_check
     except IndexError:
         pass
 
     aux = traceback.extract_tb(etb)
     assert len(records) == len(aux)
     for i, (file, lnum, _, _) in zip(range(len(records)), aux):
         maybeStart = lnum-1 - context//2
         start =  max(maybeStart, 0)
         end   = start + context
         lines = ulinecache.getlines(file)[start:end]
         buf = list(records[i])
         buf[LNUM_POS] = lnum
         buf[INDEX_POS] = lnum - 1 - start
         buf[LINES_POS] = lines
         records[i] = tuple(buf)
     return records[tb_offset:]
 
 # Helper function -- largely belongs to VerboseTB, but we need the same
 # functionality to produce a pseudo verbose TB for SyntaxErrors, so that they
 # can be recognized properly by ipython.el's py-traceback-line-re
 # (SyntaxErrors have to be treated specially because they have no traceback)
 
 _parser = PyColorize.Parser()
 
 def _format_traceback_lines(lnum, index, lines, Colors, lvals=None,scheme=None):
     numbers_width = INDENT_SIZE - 1
     res = []
     i = lnum - index
 
     # This lets us get fully syntax-highlighted tracebacks.
     if scheme is None:
         ipinst = ipapi.get()
         if ipinst is not None:
             scheme = ipinst.colors
         else:
             scheme = DEFAULT_SCHEME
 
     _line_format = _parser.format2
 
     for line in lines:
         line = py3compat.cast_unicode(line)
 
         new_line, err = _line_format(line, 'str', scheme)
         if not err: line = new_line
 
         if i == lnum:
             # This is the line with the error
             pad = numbers_width - len(str(i))
             if pad >= 3:
                 marker = '-'*(pad-3) + '-> '
             elif pad == 2:
                 marker = '> '
             elif pad == 1:
                 marker = '>'
             else:
                 marker = ''
             num = marker + str(i)
             line = '%s%s%s %s%s' %(Colors.linenoEm, num,
                                    Colors.line, line, Colors.Normal)
         else:
             num = '%*s' % (numbers_width,i)
             line = '%s%s%s %s' %(Colors.lineno, num,
                                  Colors.Normal, line)
 
         res.append(line)
         if lvals and i == lnum:
             res.append(lvals + '\n')
         i = i + 1
     return res
 
 
 #---------------------------------------------------------------------------
 # Module classes
 class TBTools(object):
     """Basic tools used by all traceback printer classes."""
 
     # Number of frames to skip when reporting tracebacks
     tb_offset = 0
 
     def __init__(self, color_scheme='NoColor', call_pdb=False, ostream=None):
         # Whether to call the interactive pdb debugger after printing
         # tracebacks or not
         self.call_pdb = call_pdb
 
         # Output stream to write to.  Note that we store the original value in
         # a private attribute and then make the public ostream a property, so
         # that we can delay accessing io.stdout until runtime.  The way
         # things are written now, the io.stdout object is dynamically managed
         # so a reference to it should NEVER be stored statically.  This
         # property approach confines this detail to a single location, and all
         # subclasses can simply access self.ostream for writing.
         self._ostream = ostream
 
         # Create color table
         self.color_scheme_table = exception_colors()
 
         self.set_colors(color_scheme)
         self.old_scheme = color_scheme  # save initial value for toggles
 
         if call_pdb:
             self.pdb = debugger.Pdb(self.color_scheme_table.active_scheme_name)
         else:
             self.pdb = None
 
     def _get_ostream(self):
         """Output stream that exceptions are written to.
 
         Valid values are:
 
         - None: the default, which means that IPython will dynamically resolve
         to io.stdout.  This ensures compatibility with most tools, including
         Windows (where plain stdout doesn't recognize ANSI escapes).
 
         - Any object with 'write' and 'flush' attributes.
         """
         return io.stdout if self._ostream is None else self._ostream
 
     def _set_ostream(self, val):
         assert val is None or (hasattr(val, 'write') and hasattr(val, 'flush'))
         self._ostream = val
 
     ostream = property(_get_ostream, _set_ostream)
 
     def set_colors(self,*args,**kw):
         """Shorthand access to the color table scheme selector method."""
 
         # Set own color table
         self.color_scheme_table.set_active_scheme(*args,**kw)
         # for convenience, set Colors to the active scheme
         self.Colors = self.color_scheme_table.active_colors
         # Also set colors of debugger
         if hasattr(self,'pdb') and self.pdb is not None:
             self.pdb.set_colors(*args,**kw)
 
     def color_toggle(self):
         """Toggle between the currently active color scheme and NoColor."""
 
         if self.color_scheme_table.active_scheme_name == 'NoColor':
             self.color_scheme_table.set_active_scheme(self.old_scheme)
             self.Colors = self.color_scheme_table.active_colors
         else:
             self.old_scheme = self.color_scheme_table.active_scheme_name
             self.color_scheme_table.set_active_scheme('NoColor')
             self.Colors = self.color_scheme_table.active_colors
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return '\n'.join(stb)
 
     def text(self, etype, value, tb, tb_offset=None, context=5):
         """Return formatted traceback.
 
         Subclasses may override this if they add extra arguments.
         """
         tb_list = self.structured_traceback(etype, value, tb,
                                             tb_offset, context)
         return self.stb2text(tb_list)
 
     def structured_traceback(self, etype, evalue, tb, tb_offset=None,
                              context=5, mode=None):
         """Return a list of traceback frames.
 
         Must be implemented by each class.
         """
         raise NotImplementedError()
 
 
 #---------------------------------------------------------------------------
 class ListTB(TBTools):
     """Print traceback information from a traceback list, with optional color.
 
     Calling requires 3 arguments: (etype, evalue, elist)
     as would be obtained by::
     
       etype, evalue, tb = sys.exc_info()
       if tb:
         elist = traceback.extract_tb(tb)
       else:
         elist = None
 
     It can thus be used by programs which need to process the traceback before
     printing (such as console replacements based on the code module from the
     standard library).
 
     Because they are meant to be called without a full traceback (only a
     list), instances of this class can't call the interactive pdb debugger."""
 
     def __init__(self,color_scheme = 'NoColor', call_pdb=False, ostream=None):
         TBTools.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                          ostream=ostream)
 
     def __call__(self, etype, value, elist):
         self.ostream.flush()
         self.ostream.write(self.text(etype, value, elist))
         self.ostream.write('\n')
 
     def structured_traceback(self, etype, value, elist, tb_offset=None,
                              context=5):
         """Return a color formatted string with the traceback info.
 
         Parameters
         ----------
         etype : exception type
           Type of the exception raised.
 
         value : object
           Data stored in the exception
 
         elist : list
           List of frames, see class docstring for details.
 
         tb_offset : int, optional
           Number of frames in the traceback to skip.  If not given, the
           instance value is used (set in constructor).
 
         context : int, optional
           Number of lines of context information to print.
 
         Returns
         -------
         String with formatted exception.
         """
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
         Colors = self.Colors
         out_list = []
         if elist:
 
             if tb_offset and len(elist) > tb_offset:
                 elist = elist[tb_offset:]
 
             out_list.append('Traceback %s(most recent call last)%s:' %
                                 (Colors.normalEm, Colors.Normal) + '\n')
             out_list.extend(self._format_list(elist))
         # The exception info should be a single entry in the list.
         lines = ''.join(self._format_exception_only(etype, value))
         out_list.append(lines)
 
         # Note: this code originally read:
 
         ## for line in lines[:-1]:
         ##     out_list.append(" "+line)
         ## out_list.append(lines[-1])
 
         # This means it was indenting everything but the last line by a little
         # bit.  I've disabled this for now, but if we see ugliness somewhre we
         # can restore it.
 
         return out_list
 
     def _format_list(self, extracted_list):
         """Format a list of traceback entry tuples for printing.
 
         Given a list of tuples as returned by extract_tb() or
         extract_stack(), return a list of strings ready for printing.
         Each string in the resulting list corresponds to the item with the
         same index in the argument list.  Each string ends in a newline;
         the strings may contain internal newlines as well, for those items
         whose source text line is not None.
 
         Lifted almost verbatim from traceback.py
         """
 
         Colors = self.Colors
         list = []
         for filename, lineno, name, line in extracted_list[:-1]:
             item = '  File %s"%s"%s, line %s%d%s, in %s%s%s\n' % \
                     (Colors.filename, filename, Colors.Normal,
                      Colors.lineno, lineno, Colors.Normal,
                      Colors.name, name, Colors.Normal)
             if line:
                 item += '    %s\n' % line.strip()
             list.append(item)
         # Emphasize the last entry
         filename, lineno, name, line = extracted_list[-1]
         item = '%s  File %s"%s"%s, line %s%d%s, in %s%s%s%s\n' % \
                 (Colors.normalEm,
                  Colors.filenameEm, filename, Colors.normalEm,
                  Colors.linenoEm, lineno, Colors.normalEm,
                  Colors.nameEm, name, Colors.normalEm,
                  Colors.Normal)
         if line:
             item += '%s    %s%s\n' % (Colors.line, line.strip(),
                                             Colors.Normal)
         list.append(item)
         #from pprint import pformat; print 'LISTTB', pformat(list) # dbg
         return list
 
     def _format_exception_only(self, etype, value):
         """Format the exception part of a traceback.
 
         The arguments are the exception type and value such as given by
         sys.exc_info()[:2]. The return value is a list of strings, each ending
         in a newline.  Normally, the list contains a single string; however,
         for SyntaxError exceptions, it contains several lines that (when
         printed) display detailed information about where the syntax error
         occurred.  The message indicating which exception occurred is the
         always last string in the list.
 
         Also lifted nearly verbatim from traceback.py
         """
         have_filedata = False
         Colors = self.Colors
         list = []
         stype = Colors.excName + etype.__name__ + Colors.Normal
         if value is None:
             # Not sure if this can still happen in Python 2.6 and above
             list.append( py3compat.cast_unicode(stype) + '\n')
         else:
             if issubclass(etype, SyntaxError):
                 have_filedata = True
                 #print 'filename is',filename  # dbg
                 if not value.filename: value.filename = "<string>"
                 if value.lineno:
                     lineno = value.lineno
                     textline = ulinecache.getline(value.filename, value.lineno)
                 else:
                     lineno = 'unknown'
                     textline = ''
                 list.append('%s  File %s"%s"%s, line %s%s%s\n' % \
                         (Colors.normalEm,
                          Colors.filenameEm, py3compat.cast_unicode(value.filename), Colors.normalEm,
                          Colors.linenoEm, lineno, Colors.Normal  ))
                 if textline == '':
                     textline = py3compat.cast_unicode(value.text, "utf-8")
 
                 if textline is not None:
                     i = 0
                     while i < len(textline) and textline[i].isspace():
                         i += 1
                     list.append('%s    %s%s\n' % (Colors.line,
                                                   textline.strip(),
                                                   Colors.Normal))
                     if value.offset is not None:
                         s = '    '
                         for c in textline[i:value.offset-1]:
                             if c.isspace():
                                 s += c
                             else:
                                 s += ' '
                         list.append('%s%s^%s\n' % (Colors.caret, s,
                                                    Colors.Normal) )
 
             try:
                 s = value.msg
             except Exception:
                 s = self._some_str(value)
             if s:
                 list.append('%s%s:%s %s\n' % (str(stype), Colors.excName,
                                               Colors.Normal, s))
             else:
                 list.append('%s\n' % str(stype))
 
         # sync with user hooks
         if have_filedata:
             ipinst = ipapi.get()
             if ipinst is not None:
                 ipinst.hooks.synchronize_with_editor(value.filename, value.lineno, 0)
 
         return list
 
     def get_exception_only(self, etype, value):
         """Only print the exception type and message, without a traceback.
 
         Parameters
         ----------
         etype : exception type
         value : exception value
         """
         return ListTB.structured_traceback(self, etype, value, [])
 
 
     def show_exception_only(self, etype, evalue):
         """Only print the exception type and message, without a traceback.
 
         Parameters
         ----------
         etype : exception type
         value : exception value
         """
         # This method needs to use __call__ from *this* class, not the one from
         # a subclass whose signature or behavior may be different
         ostream = self.ostream
         ostream.flush()
         ostream.write('\n'.join(self.get_exception_only(etype, evalue)))
         ostream.flush()
 
     def _some_str(self, value):
         # Lifted from traceback.py
         try:
             return str(value)
         except:
             return '<unprintable %s object>' % type(value).__name__
 
 #----------------------------------------------------------------------------
 class VerboseTB(TBTools):
     """A port of Ka-Ping Yee's cgitb.py module that outputs color text instead
     of HTML.  Requires inspect and pydoc.  Crazy, man.
 
     Modified version which optionally strips the topmost entries from the
     traceback, to be used with alternate interpreters (because their own code
     would appear in the traceback)."""
 
     def __init__(self,color_scheme = 'Linux', call_pdb=False, ostream=None,
                  tb_offset=0, long_header=False, include_vars=True,
                  check_cache=None):
         """Specify traceback offset, headers and color scheme.
 
         Define how many frames to drop from the tracebacks. Calling it with
         tb_offset=1 allows use of this handler in interpreters which will have
         their own code at the top of the traceback (VerboseTB will first
         remove that frame before printing the traceback info)."""
         TBTools.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                          ostream=ostream)
         self.tb_offset = tb_offset
         self.long_header = long_header
         self.include_vars = include_vars
         # By default we use linecache.checkcache, but the user can provide a
         # different check_cache implementation.  This is used by the IPython
         # kernel to provide tracebacks for interactive code that is cached,
         # by a compiler instance that flushes the linecache but preserves its
         # own code cache.
         if check_cache is None:
             check_cache = linecache.checkcache
         self.check_cache = check_cache
 
     def structured_traceback(self, etype, evalue, etb, tb_offset=None,
                              context=5):
         """Return a nice text document describing the traceback."""
 
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
 
         # some locals
         try:
             etype = etype.__name__
         except AttributeError:
             pass
         Colors        = self.Colors   # just a shorthand + quicker name lookup
         ColorsNormal  = Colors.Normal  # used a lot
         col_scheme    = self.color_scheme_table.active_scheme_name
         indent        = ' '*INDENT_SIZE
         em_normal     = '%s\n%s%s' % (Colors.valEm, indent,ColorsNormal)
         undefined     = '%sundefined%s' % (Colors.em, ColorsNormal)
         exc = '%s%s%s' % (Colors.excName,etype,ColorsNormal)
 
         # some internal-use functions
         def text_repr(value):
             """Hopefully pretty robust repr equivalent."""
             # this is pretty horrible but should always return *something*
             try:
                 return pydoc.text.repr(value)
             except KeyboardInterrupt:
                 raise
             except:
                 try:
                     return repr(value)
                 except KeyboardInterrupt:
                     raise
                 except:
                     try:
                         # all still in an except block so we catch
                         # getattr raising
                         name = getattr(value, '__name__', None)
                         if name:
                             # ick, recursion
                             return text_repr(name)
                         klass = getattr(value, '__class__', None)
                         if klass:
                             return '%s instance' % text_repr(klass)
                     except KeyboardInterrupt:
                         raise
                     except:
                         return 'UNRECOVERABLE REPR FAILURE'
         def eqrepr(value, repr=text_repr): return '=%s' % repr(value)
         def nullrepr(value, repr=text_repr): return ''
 
         # meat of the code begins
         try:
             etype = etype.__name__
         except AttributeError:
             pass
 
         if self.long_header:
             # Header with the exception type, python version, and date
             pyver = 'Python ' + sys.version.split()[0] + ': ' + sys.executable
             date = time.ctime(time.time())
 
             head = '%s%s%s\n%s%s%s\n%s' % (Colors.topline, '-'*75, ColorsNormal,
                                            exc, ' '*(75-len(str(etype))-len(pyver)),
                                            pyver, date.rjust(75) )
             head += "\nA problem occured executing Python code.  Here is the sequence of function"\
                     "\ncalls leading up to the error, with the most recent (innermost) call last."
         else:
             # Simplified header
             head = '%s%s%s\n%s%s' % (Colors.topline, '-'*75, ColorsNormal,exc,
                                      'Traceback (most recent call last)'.\
                                                   rjust(75 - len(str(etype)) ) )
         frames = []
         # Flush cache before calling inspect.  This helps alleviate some of the
         # problems with python 2.3's inspect.py.
         ##self.check_cache()
         # Drop topmost frames if requested
         try:
             # Try the default getinnerframes and Alex's: Alex's fixes some
             # problems, but it generates empty tracebacks for console errors
             # (5 blanks lines) where none should be returned.
             #records = inspect.getinnerframes(etb, context)[tb_offset:]
             #print 'python records:', records # dbg
             records = _fixed_getinnerframes(etb, context, tb_offset)
             #print 'alex   records:', records # dbg
         except:
 
             # FIXME: I've been getting many crash reports from python 2.3
             # users, traceable to inspect.py.  If I can find a small test-case
             # to reproduce this, I should either write a better workaround or
             # file a bug report against inspect (if that's the real problem).
             # So far, I haven't been able to find an isolated example to
             # reproduce the problem.
             inspect_error()
             traceback.print_exc(file=self.ostream)
             info('\nUnfortunately, your original traceback can not be constructed.\n')
             return ''
 
         # build some color string templates outside these nested loops
         tpl_link       = '%s%%s%s' % (Colors.filenameEm,ColorsNormal)
         tpl_call       = 'in %s%%s%s%%s%s' % (Colors.vName, Colors.valEm,
                                               ColorsNormal)
         tpl_call_fail  = 'in %s%%s%s(***failed resolving arguments***)%s' % \
                          (Colors.vName, Colors.valEm, ColorsNormal)
         tpl_local_var  = '%s%%s%s' % (Colors.vName, ColorsNormal)
         tpl_global_var = '%sglobal%s %s%%s%s' % (Colors.em, ColorsNormal,
                                                  Colors.vName, ColorsNormal)
         tpl_name_val   = '%%s %s= %%s%s' % (Colors.valEm, ColorsNormal)
         tpl_line       = '%s%%s%s %%s' % (Colors.lineno, ColorsNormal)
         tpl_line_em    = '%s%%s%s %%s%s' % (Colors.linenoEm,Colors.line,
                                             ColorsNormal)
 
         # now, loop over all records printing context and info
         abspath = os.path.abspath
         for frame, file, lnum, func, lines, index in records:
             #print '*** record:',file,lnum,func,lines,index  # dbg
             if not file:
                 file = '?'
             elif not(file.startswith(str("<")) and file.endswith(str(">"))):
                 # Guess that filenames like <string> aren't real filenames, so
                 # don't call abspath on them.                    
                 try:
                     file = abspath(file)
                 except OSError:
                     # Not sure if this can still happen: abspath now works with
                     # file names like <string>
                     pass
             file = py3compat.cast_unicode(file, util_path.fs_encoding)
             link = tpl_link % file
             args, varargs, varkw, locals = inspect.getargvalues(frame)
 
             if func == '?':
                 call = ''
             else:
                 # Decide whether to include variable details or not
                 var_repr = self.include_vars and eqrepr or nullrepr
                 try:
                     call = tpl_call % (func,inspect.formatargvalues(args,
                                                 varargs, varkw,
                                                 locals,formatvalue=var_repr))
                 except KeyError:
                     # This happens in situations like errors inside generator
                     # expressions, where local variables are listed in the
                     # line, but can't be extracted from the frame.  I'm not
                     # 100% sure this isn't actually a bug in inspect itself,
                     # but since there's no info for us to compute with, the
                     # best we can do is report the failure and move on.  Here
                     # we must *not* call any traceback construction again,
                     # because that would mess up use of %debug later on.  So we
                     # simply report the failure and move on.  The only
                     # limitation will be that this frame won't have locals
                     # listed in the call signature.  Quite subtle problem...
                     # I can't think of a good way to validate this in a unit
                     # test, but running a script consisting of:
                     #  dict( (k,v.strip()) for (k,v) in range(10) )
                     # will illustrate the error, if this exception catch is
                     # disabled.
                     call = tpl_call_fail % func
             
             # Don't attempt to tokenize binary files.
             if file.endswith(('.so', '.pyd', '.dll')):
                 frames.append('%s %s\n' % (link,call))
                 continue
             elif file.endswith(('.pyc','.pyo')):
                 # Look up the corresponding source file.
-                file = pyfile.source_from_cache(file)
+                file = openpy.source_from_cache(file)
 
             def linereader(file=file, lnum=[lnum], getline=ulinecache.getline):
                 line = getline(file, lnum[0])
                 lnum[0] += 1
                 return line
 
             # Build the list of names on this line of code where the exception
             # occurred.
             try:
                 names = []
                 name_cont = False
                 
                 for token_type, token, start, end, line in generate_tokens(linereader):
                     # build composite names
                     if token_type == tokenize.NAME and token not in keyword.kwlist:
                         if name_cont:
                             # Continuation of a dotted name
                             try:
                                 names[-1].append(token)
                             except IndexError:
                                 names.append([token])
                             name_cont = False
                         else:
                             # Regular new names.  We append everything, the caller
                             # will be responsible for pruning the list later.  It's
                             # very tricky to try to prune as we go, b/c composite
                             # names can fool us.  The pruning at the end is easy
                             # to do (or the caller can print a list with repeated
                             # names if so desired.
                             names.append([token])
                     elif token == '.':
                         name_cont = True
                     elif token_type == tokenize.NEWLINE:
                         break
                         
             except (IndexError, UnicodeDecodeError):
                 # signals exit of tokenizer
                 pass
             except tokenize.TokenError as msg:
                 _m = ("An unexpected error occurred while tokenizing input\n"
                       "The following traceback may be corrupted or invalid\n"
                       "The error message is: %s\n" % msg)
                 error(_m)
 
             # Join composite names (e.g. "dict.fromkeys")
             names = ['.'.join(n) for n in names]
             # prune names list of duplicates, but keep the right order
             unique_names = uniq_stable(names)
 
             # Start loop over vars
             lvals = []
             if self.include_vars:
                 for name_full in unique_names:
                     name_base = name_full.split('.',1)[0]
                     if name_base in frame.f_code.co_varnames:
                         if name_base in locals:
                             try:
                                 value = repr(eval(name_full,locals))
                             except:
                                 value = undefined
                         else:
                             value = undefined
                         name = tpl_local_var % name_full
                     else:
                         if name_base in frame.f_globals:
                             try:
                                 value = repr(eval(name_full,frame.f_globals))
                             except:
                                 value = undefined
                         else:
                             value = undefined
                         name = tpl_global_var % name_full
                     lvals.append(tpl_name_val % (name,value))
             if lvals:
                 lvals = '%s%s' % (indent,em_normal.join(lvals))
             else:
                 lvals = ''
 
             level = '%s %s\n' % (link,call)
 
             if index is None:
                 frames.append(level)
             else:
                 frames.append('%s%s' % (level,''.join(
                     _format_traceback_lines(lnum,index,lines,Colors,lvals,
                                             col_scheme))))
 
         # Get (safely) a string form of the exception info
         try:
             etype_str,evalue_str = map(str,(etype,evalue))
         except:
             # User exception is improperly defined.
             etype,evalue = str,sys.exc_info()[:2]
             etype_str,evalue_str = map(str,(etype,evalue))
         # ... and format it
         exception = ['%s%s%s: %s' % (Colors.excName, etype_str,
                                      ColorsNormal, py3compat.cast_unicode(evalue_str))]
         if (not py3compat.PY3) and type(evalue) is types.InstanceType:
             try:
                 names = [w for w in dir(evalue) if isinstance(w, basestring)]
             except:
                 # Every now and then, an object with funny inernals blows up
                 # when dir() is called on it.  We do the best we can to report
                 # the problem and continue
                 _m = '%sException reporting error (object with broken dir())%s:'
                 exception.append(_m % (Colors.excName,ColorsNormal))
                 etype_str,evalue_str = map(str,sys.exc_info()[:2])
                 exception.append('%s%s%s: %s' % (Colors.excName,etype_str,
                                      ColorsNormal, py3compat.cast_unicode(evalue_str)))
                 names = []
             for name in names:
                 value = text_repr(getattr(evalue, name))
                 exception.append('\n%s%s = %s' % (indent, name, value))
 
         # vds: >>
         if records:
              filepath, lnum = records[-1][1:3]
              #print "file:", str(file), "linenb", str(lnum) # dbg
              filepath = os.path.abspath(filepath)
              ipinst = ipapi.get()
              if ipinst is not None:
                  ipinst.hooks.synchronize_with_editor(filepath, lnum, 0)
         # vds: <<
 
         # return all our info assembled as a single string
         # return '%s\n\n%s\n%s' % (head,'\n'.join(frames),''.join(exception[0]) )
         return [head] + frames + [''.join(exception[0])]
 
     def debugger(self,force=False):
         """Call up the pdb debugger if desired, always clean up the tb
         reference.
 
         Keywords:
 
           - force(False): by default, this routine checks the instance call_pdb
           flag and does not actually invoke the debugger if the flag is false.
           The 'force' option forces the debugger to activate even if the flag
           is false.
 
         If the call_pdb flag is set, the pdb interactive debugger is
         invoked. In all cases, the self.tb reference to the current traceback
         is deleted to prevent lingering references which hamper memory
         management.
 
         Note that each call to pdb() does an 'import readline', so if your app
         requires a special setup for the readline completers, you'll have to
         fix that by hand after invoking the exception handler."""
 
         if force or self.call_pdb:
             if self.pdb is None:
                 self.pdb = debugger.Pdb(
                     self.color_scheme_table.active_scheme_name)
             # the system displayhook may have changed, restore the original
             # for pdb
             display_trap = DisplayTrap(hook=sys.__displayhook__)
             with display_trap:
                 self.pdb.reset()
                 # Find the right frame so we don't pop up inside ipython itself
                 if hasattr(self,'tb') and self.tb is not None:
                     etb = self.tb
                 else:
                     etb = self.tb = sys.last_traceback
                 while self.tb is not None and self.tb.tb_next is not None:
                     self.tb = self.tb.tb_next
                 if etb and etb.tb_next:
                     etb = etb.tb_next
                 self.pdb.botframe = etb.tb_frame
                 self.pdb.interaction(self.tb.tb_frame, self.tb)
 
         if hasattr(self,'tb'):
             del self.tb
 
     def handler(self, info=None):
         (etype, evalue, etb) = info or sys.exc_info()
         self.tb = etb
         ostream = self.ostream
         ostream.flush()
         ostream.write(self.text(etype, evalue, etb))
         ostream.write('\n')
         ostream.flush()
 
     # Changed so an instance can just be called as VerboseTB_inst() and print
     # out the right info on its own.
     def __call__(self, etype=None, evalue=None, etb=None):
         """This hook can replace sys.excepthook (for Python 2.1 or higher)."""
         if etb is None:
             self.handler()
         else:
             self.handler((etype, evalue, etb))
         try:
             self.debugger()
         except KeyboardInterrupt:
             print "\nKeyboardInterrupt"
 
 #----------------------------------------------------------------------------
 class FormattedTB(VerboseTB, ListTB):
     """Subclass ListTB but allow calling with a traceback.
 
     It can thus be used as a sys.excepthook for Python > 2.1.
 
     Also adds 'Context' and 'Verbose' modes, not available in ListTB.
 
     Allows a tb_offset to be specified. This is useful for situations where
     one needs to remove a number of topmost frames from the traceback (such as
     occurs with python programs that themselves execute other python code,
     like Python shells).  """
 
     def __init__(self, mode='Plain', color_scheme='Linux', call_pdb=False,
                  ostream=None,
                  tb_offset=0, long_header=False, include_vars=False,
                  check_cache=None):
 
         # NEVER change the order of this list. Put new modes at the end:
         self.valid_modes = ['Plain','Context','Verbose']
         self.verbose_modes = self.valid_modes[1:3]
 
         VerboseTB.__init__(self, color_scheme=color_scheme, call_pdb=call_pdb,
                            ostream=ostream, tb_offset=tb_offset,
                            long_header=long_header, include_vars=include_vars,
                            check_cache=check_cache)
 
         # Different types of tracebacks are joined with different separators to
         # form a single string.  They are taken from this dict
         self._join_chars = dict(Plain='', Context='\n', Verbose='\n')
         # set_mode also sets the tb_join_char attribute
         self.set_mode(mode)
 
     def _extract_tb(self,tb):
         if tb:
             return traceback.extract_tb(tb)
         else:
             return None
 
     def structured_traceback(self, etype, value, tb, tb_offset=None, context=5):
         tb_offset = self.tb_offset if tb_offset is None else tb_offset
         mode = self.mode
         if mode in self.verbose_modes:
             # Verbose modes need a full traceback
             return VerboseTB.structured_traceback(
                 self, etype, value, tb, tb_offset, context
             )
         else:
             # We must check the source cache because otherwise we can print
             # out-of-date source code.
             self.check_cache()
             # Now we can extract and format the exception
             elist = self._extract_tb(tb)
             return ListTB.structured_traceback(
                 self, etype, value, elist, tb_offset, context
             )
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return self.tb_join_char.join(stb)
 
 
     def set_mode(self,mode=None):
         """Switch to the desired mode.
 
         If mode is not specified, cycles through the available modes."""
 
         if not mode:
             new_idx = ( self.valid_modes.index(self.mode) + 1 ) % \
                       len(self.valid_modes)
             self.mode = self.valid_modes[new_idx]
         elif mode not in self.valid_modes:
             raise ValueError('Unrecognized mode in FormattedTB: <'+mode+'>\n'
                              'Valid modes: '+str(self.valid_modes))
         else:
             self.mode = mode
         # include variable details only in 'Verbose' mode
         self.include_vars = (self.mode == self.valid_modes[2])
         # Set the join character for generating text tracebacks
         self.tb_join_char = self._join_chars[self.mode]
 
     # some convenient shorcuts
     def plain(self):
         self.set_mode(self.valid_modes[0])
 
     def context(self):
         self.set_mode(self.valid_modes[1])
 
     def verbose(self):
         self.set_mode(self.valid_modes[2])
 
 #----------------------------------------------------------------------------
 class AutoFormattedTB(FormattedTB):
     """A traceback printer which can be called on the fly.
 
     It will find out about exceptions by itself.
 
     A brief example::
 
         AutoTB = AutoFormattedTB(mode = 'Verbose',color_scheme='Linux')
         try:
           ...
         except:
           AutoTB()  # or AutoTB(out=logfile) where logfile is an open file object
     """
 
     def __call__(self,etype=None,evalue=None,etb=None,
                  out=None,tb_offset=None):
         """Print out a formatted exception traceback.
 
         Optional arguments:
           - out: an open file-like object to direct output to.
 
           - tb_offset: the number of frames to skip over in the stack, on a
           per-call basis (this overrides temporarily the instance's tb_offset
           given at initialization time.  """
 
 
         if out is None:
             out = self.ostream
         out.flush()
         out.write(self.text(etype, evalue, etb, tb_offset))
         out.write('\n')
         out.flush()
         # FIXME: we should remove the auto pdb behavior from here and leave
         # that to the clients.
         try:
             self.debugger()
         except KeyboardInterrupt:
             print "\nKeyboardInterrupt"
 
     def structured_traceback(self, etype=None, value=None, tb=None,
                              tb_offset=None, context=5):
         if etype is None:
             etype,value,tb = sys.exc_info()
         self.tb = tb
         return FormattedTB.structured_traceback(
             self, etype, value, tb, tb_offset, context)
 
 #---------------------------------------------------------------------------
 
 # A simple class to preserve Nathan's original functionality.
 class ColorTB(FormattedTB):
     """Shorthand to initialize a FormattedTB in Linux colors mode."""
     def __init__(self,color_scheme='Linux',call_pdb=0):
         FormattedTB.__init__(self,color_scheme=color_scheme,
                              call_pdb=call_pdb)
 
 
 class SyntaxTB(ListTB):
     """Extension which holds some state: the last exception value"""
 
     def __init__(self,color_scheme = 'NoColor'):
         ListTB.__init__(self,color_scheme)
         self.last_syntax_error = None
 
     def __call__(self, etype, value, elist):
         self.last_syntax_error = value
         ListTB.__call__(self,etype,value,elist)
 
     def clear_err_state(self):
         """Return the current error state and clear it"""
         e = self.last_syntax_error
         self.last_syntax_error = None
         return e
 
     def stb2text(self, stb):
         """Convert a structured traceback (a list) to a string."""
         return ''.join(stb)
 
 
 #----------------------------------------------------------------------------
 # module testing (minimal)
 if __name__ == "__main__":
     def spam(c, d_e):
         (d, e) = d_e
         x = c + d
         y = c * d
         foo(x, y)
 
     def foo(a, b, bar=1):
         eggs(a, b + bar)
 
     def eggs(f, g, z=globals()):
         h = f + g
         i = f - g
         return h / i
 
     print ''
     print '*** Before ***'
     try:
         print spam(1, (2, 3))
     except:
         traceback.print_exc()
     print ''
 
     handler = ColorTB()
     print '*** ColorTB ***'
     try:
         print spam(1, (2, 3))
     except:
         handler(*sys.exc_info())
     print ''
 
     handler = VerboseTB()
     print '*** VerboseTB ***'
     try:
         print spam(1, (2, 3))
     except:
         handler(*sys.exc_info())
     print ''
 

IPython/extensions/autoreload.py

@@ -1,509 +1,509
 """IPython extension to reload modules before executing user code.
 
 ``autoreload`` reloads modules automatically before entering the execution of
 code typed at the IPython prompt.
 
 This makes for example the following workflow possible:
 
 .. sourcecode:: ipython
 
    In [1]: %load_ext autoreload
 
    In [2]: %autoreload 2
 
    In [3]: from foo import some_function
 
    In [4]: some_function()
    Out[4]: 42
 
    In [5]: # open foo.py in an editor and change some_function to return 43
 
    In [6]: some_function()
    Out[6]: 43
 
 The module was reloaded without reloading it explicitly, and the object
 imported with ``from foo import ...`` was also updated.
 
 Usage
 =====
 
 The following magic commands are provided:
 
 ``%autoreload``
 
     Reload all modules (except those excluded by ``%aimport``)
     automatically now.
 
 ``%autoreload 0``
 
     Disable automatic reloading.
 
 ``%autoreload 1``
 
     Reload all modules imported with ``%aimport`` every time before
     executing the Python code typed.
 
 ``%autoreload 2``
 
     Reload all modules (except those excluded by ``%aimport``) every
     time before executing the Python code typed.
 
 ``%aimport``
 
     List modules which are to be automatically imported or not to be imported.
 
 ``%aimport foo``
 
     Import module 'foo' and mark it to be autoreloaded for ``%autoreload 1``
 
 ``%aimport -foo``
 
     Mark module 'foo' to not be autoreloaded.
 
 Caveats
 =======
 
 Reloading Python modules in a reliable way is in general difficult,
 and unexpected things may occur. ``%autoreload`` tries to work around
 common pitfalls by replacing function code objects and parts of
 classes previously in the module with new versions. This makes the
 following things to work:
 
 - Functions and classes imported via 'from xxx import foo' are upgraded
   to new versions when 'xxx' is reloaded.
 
 - Methods and properties of classes are upgraded on reload, so that
   calling 'c.foo()' on an object 'c' created before the reload causes
   the new code for 'foo' to be executed.
 
 Some of the known remaining caveats are:
 
 - Replacing code objects does not always succeed: changing a @property
   in a class to an ordinary method or a method to a member variable
   can cause problems (but in old objects only).
 
 - Functions that are removed (eg. via monkey-patching) from a module
   before it is reloaded are not upgraded.
 
 - C extension modules cannot be reloaded, and so cannot be autoreloaded.
 """
 from __future__ import print_function
 
 skip_doctest = True
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2000 Thomas Heller
 #  Copyright (C) 2008 Pauli Virtanen <[e-mail]>
 #  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.
 #-----------------------------------------------------------------------------
 #
 # This IPython module is written by Pauli Virtanen, based on the autoreload
 # code by Thomas Heller.
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import sys
 import traceback
 import types
 import weakref
 
 try:
     # Reload is not defined by default in Python3.
     reload
 except NameError:
     from imp import reload
 
-from IPython.utils import pyfile
+from IPython.utils import openpy
 from IPython.utils.py3compat import PY3
 
 #------------------------------------------------------------------------------
 # Autoreload functionality
 #------------------------------------------------------------------------------
 
 class ModuleReloader(object):
     enabled = False
     """Whether this reloader is enabled"""
 
     failed = {}
     """Modules that failed to reload: {module: mtime-on-failed-reload, ...}"""
 
     modules = {}
     """Modules specially marked as autoreloadable."""
 
     skip_modules = {}
     """Modules specially marked as not autoreloadable."""
 
     check_all = True
     """Autoreload all modules, not just those listed in 'modules'"""
 
     old_objects = {}
     """(module-name, name) -> weakref, for replacing old code objects"""
 
     def mark_module_skipped(self, module_name):
         """Skip reloading the named module in the future"""
         try:
             del self.modules[module_name]
         except KeyError:
             pass
         self.skip_modules[module_name] = True
 
     def mark_module_reloadable(self, module_name):
         """Reload the named module in the future (if it is imported)"""
         try:
             del self.skip_modules[module_name]
         except KeyError:
             pass
         self.modules[module_name] = True
 
     def aimport_module(self, module_name):
         """Import a module, and mark it reloadable
 
         Returns
         -------
         top_module : module
             The imported module if it is top-level, or the top-level
         top_name : module
             Name of top_module
 
         """
         self.mark_module_reloadable(module_name)
 
         __import__(module_name)
         top_name = module_name.split('.')[0]
         top_module = sys.modules[top_name]
         return top_module, top_name
 
     def check(self, check_all=False):
         """Check whether some modules need to be reloaded."""
 
         if not self.enabled and not check_all:
             return
 
         if check_all or self.check_all:
             modules = sys.modules.keys()
         else:
             modules = self.modules.keys()
 
         for modname in modules:
             m = sys.modules.get(modname, None)
 
             if modname in self.skip_modules:
                 continue
 
             if not hasattr(m, '__file__'):
                 continue
 
             if m.__name__ == '__main__':
                 # we cannot reload(__main__)
                 continue
 
             filename = m.__file__
             path, ext = os.path.splitext(filename)
 
             if ext.lower() == '.py':
-                pyc_filename = pyfile.cache_from_source(filename)
+                pyc_filename = openpy.cache_from_source(filename)
                 py_filename = filename
             else:
                 pyc_filename = filename
                 try:
-                    py_filename = pyfile.source_from_cache(filename)
+                    py_filename = openpy.source_from_cache(filename)
                 except ValueError:
                     continue
 
             try:
                 pymtime = os.stat(py_filename).st_mtime
                 if pymtime <= os.stat(pyc_filename).st_mtime:
                     continue
                 if self.failed.get(py_filename, None) == pymtime:
                     continue
             except OSError:
                 continue
 
             try:
                 superreload(m, reload, self.old_objects)
                 if py_filename in self.failed:
                     del self.failed[py_filename]
             except:
                 print("[autoreload of %s failed: %s]" % (
                         modname, traceback.format_exc(1)), file=sys.stderr)
                 self.failed[py_filename] = pymtime
 
 #------------------------------------------------------------------------------
 # superreload
 #------------------------------------------------------------------------------
 
 if PY3:
     func_attrs = ['__code__', '__defaults__', '__doc__',
                   '__closure__', '__globals__', '__dict__']
 else:
     func_attrs = ['func_code', 'func_defaults', 'func_doc',
                   'func_closure', 'func_globals', 'func_dict']
 
 
 def update_function(old, new):
     """Upgrade the code object of a function"""
     for name in func_attrs:
         try:
             setattr(old, name, getattr(new, name))
         except (AttributeError, TypeError):
             pass
 
 
 def update_class(old, new):
     """Replace stuff in the __dict__ of a class, and upgrade
     method code objects"""
     for key in old.__dict__.keys():
         old_obj = getattr(old, key)
 
         try:
             new_obj = getattr(new, key)
         except AttributeError:
             # obsolete attribute: remove it
             try:
                 delattr(old, key)
             except (AttributeError, TypeError):
                 pass
             continue
 
         if update_generic(old_obj, new_obj): continue
 
         try:
             setattr(old, key, getattr(new, key))
         except (AttributeError, TypeError):
             pass # skip non-writable attributes
 
 
 def update_property(old, new):
     """Replace get/set/del functions of a property"""
     update_generic(old.fdel, new.fdel)
     update_generic(old.fget, new.fget)
     update_generic(old.fset, new.fset)
 
 
 def isinstance2(a, b, typ):
     return isinstance(a, typ) and isinstance(b, typ)
 
 
 UPDATE_RULES = [
     (lambda a, b: isinstance2(a, b, type),
      update_class),
     (lambda a, b: isinstance2(a, b, types.FunctionType),
      update_function),
     (lambda a, b: isinstance2(a, b, property),
      update_property),
 ]
 
 
 if PY3:
     UPDATE_RULES.extend([(lambda a, b: isinstance2(a, b, types.MethodType),
                           lambda a, b: update_function(a.__func__, b.__func__)),
                         ])
 else:
     UPDATE_RULES.extend([(lambda a, b: isinstance2(a, b, types.ClassType),
                           update_class),
                          (lambda a, b: isinstance2(a, b, types.MethodType),
                           lambda a, b: update_function(a.im_func, b.im_func)),
                         ])
 
 
 def update_generic(a, b):
     for type_check, update in UPDATE_RULES:
         if type_check(a, b):
             update(a, b)
             return True
     return False
 
 
 class StrongRef(object):
     def __init__(self, obj):
         self.obj = obj
     def __call__(self):
         return self.obj
 
 
 def superreload(module, reload=reload, old_objects={}):
     """Enhanced version of the builtin reload function.
 
     superreload remembers objects previously in the module, and
 
     - upgrades the class dictionary of every old class in the module
     - upgrades the code object of every old function and method
     - clears the module's namespace before reloading
 
     """
 
     # collect old objects in the module
     for name, obj in module.__dict__.items():
         if not hasattr(obj, '__module__') or obj.__module__ != module.__name__:
             continue
         key = (module.__name__, name)
         try:
             old_objects.setdefault(key, []).append(weakref.ref(obj))
         except TypeError:
             # weakref doesn't work for all types;
             # create strong references for 'important' cases
             if not PY3 and isinstance(obj, types.ClassType):
                 old_objects.setdefault(key, []).append(StrongRef(obj))
 
     # reload module
     try:
         # clear namespace first from old cruft
         old_dict = module.__dict__.copy()
         old_name = module.__name__
         module.__dict__.clear()
         module.__dict__['__name__'] = old_name
         module.__dict__['__loader__'] = old_dict['__loader__']
     except (TypeError, AttributeError, KeyError):
         pass
 
     try:
         module = reload(module)
     except:
         # restore module dictionary on failed reload
         module.__dict__.update(old_dict)
         raise
 
     # iterate over all objects and update functions & classes
     for name, new_obj in module.__dict__.items():
         key = (module.__name__, name)
         if key not in old_objects: continue
 
         new_refs = []
         for old_ref in old_objects[key]:
             old_obj = old_ref()
             if old_obj is None: continue
             new_refs.append(old_ref)
             update_generic(old_obj, new_obj)
 
         if new_refs:
             old_objects[key] = new_refs
         else:
             del old_objects[key]
 
     return module
 
 #------------------------------------------------------------------------------
 # IPython connectivity
 #------------------------------------------------------------------------------
 
 from IPython.core.hooks import TryNext
 from IPython.core.magic import Magics, magics_class, line_magic
 
 @magics_class
 class AutoreloadMagics(Magics):
     def __init__(self, *a, **kw):
         super(AutoreloadMagics, self).__init__(*a, **kw)
         self._reloader = ModuleReloader()
         self._reloader.check_all = False
 
     @line_magic
     def autoreload(self, parameter_s=''):
         r"""%autoreload => Reload modules automatically
 
         %autoreload
         Reload all modules (except those excluded by %aimport) automatically
         now.
 
         %autoreload 0
         Disable automatic reloading.
 
         %autoreload 1
         Reload all modules imported with %aimport every time before executing
         the Python code typed.
 
         %autoreload 2
         Reload all modules (except those excluded by %aimport) every time
         before executing the Python code typed.
 
         Reloading Python modules in a reliable way is in general
         difficult, and unexpected things may occur. %autoreload tries to
         work around common pitfalls by replacing function code objects and
         parts of classes previously in the module with new versions. This
         makes the following things to work:
 
         - Functions and classes imported via 'from xxx import foo' are upgraded
           to new versions when 'xxx' is reloaded.
 
         - Methods and properties of classes are upgraded on reload, so that
           calling 'c.foo()' on an object 'c' created before the reload causes
           the new code for 'foo' to be executed.
 
         Some of the known remaining caveats are:
 
         - Replacing code objects does not always succeed: changing a @property
           in a class to an ordinary method or a method to a member variable
           can cause problems (but in old objects only).
 
         - Functions that are removed (eg. via monkey-patching) from a module
           before it is reloaded are not upgraded.
 
         - C extension modules cannot be reloaded, and so cannot be
           autoreloaded.
 
         """
         if parameter_s == '':
             self._reloader.check(True)
         elif parameter_s == '0':
             self._reloader.enabled = False
         elif parameter_s == '1':
             self._reloader.check_all = False
             self._reloader.enabled = True
         elif parameter_s == '2':
             self._reloader.check_all = True
             self._reloader.enabled = True
 
     @line_magic
     def aimport(self, parameter_s='', stream=None):
         """%aimport => Import modules for automatic reloading.
 
         %aimport
         List modules to automatically import and not to import.
 
         %aimport foo
         Import module 'foo' and mark it to be autoreloaded for %autoreload 1
 
         %aimport -foo
         Mark module 'foo' to not be autoreloaded for %autoreload 1
         """
         modname = parameter_s
         if not modname:
             to_reload = self._reloader.modules.keys()
             to_reload.sort()
             to_skip = self._reloader.skip_modules.keys()
             to_skip.sort()
             if stream is None:
                 stream = sys.stdout
             if self._reloader.check_all:
                 stream.write("Modules to reload:\nall-except-skipped\n")
             else:
                 stream.write("Modules to reload:\n%s\n" % ' '.join(to_reload))
             stream.write("\nModules to skip:\n%s\n" % ' '.join(to_skip))
         elif modname.startswith('-'):
             modname = modname[1:]
             self._reloader.mark_module_skipped(modname)
         else:
             top_module, top_name = self._reloader.aimport_module(modname)
 
             # Inject module to user namespace
             self.shell.push({top_name: top_module})
 
     def pre_run_code_hook(self, ip):
         if not self._reloader.enabled:
             raise TryNext
         try:
             self._reloader.check()
         except:
             pass
 
 
 def load_ipython_extension(ip):
     """Load the extension in IPython."""
     auto_reload = AutoreloadMagics(ip)
     ip.register_magics(auto_reload)
     ip.set_hook('pre_run_code_hook', auto_reload.pre_run_code_hook)

IPython/lib/demo.py

@@ -1,582 +1,582
 """Module for interactive demos using IPython.
 
 This module implements a few classes for running Python scripts interactively
 in IPython for demonstrations.  With very simple markup (a few tags in
 comments), you can control points where the script stops executing and returns
 control to IPython.
 
 
 Provided classes
 ----------------
 
 The classes are (see their docstrings for further details):
 
  - Demo: pure python demos
 
  - IPythonDemo: demos with input to be processed by IPython as if it had been
  typed interactively (so magics work, as well as any other special syntax you
  may have added via input prefilters).
 
  - LineDemo: single-line version of the Demo class.  These demos are executed
  one line at a time, and require no markup.
 
  - IPythonLineDemo: IPython version of the LineDemo class (the demo is
  executed a line at a time, but processed via IPython).
 
  - ClearMixin: mixin to make Demo classes with less visual clutter.  It
    declares an empty marquee and a pre_cmd that clears the screen before each
    block (see Subclassing below).
 
  - ClearDemo, ClearIPDemo: mixin-enabled versions of the Demo and IPythonDemo
    classes.
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.lib.demo
    :parts: 3
 
 Subclassing
 -----------
 
 The classes here all include a few methods meant to make customization by
 subclassing more convenient.  Their docstrings below have some more details:
 
   - marquee(): generates a marquee to provide visible on-screen markers at each
     block start and end.
 
   - pre_cmd(): run right before the execution of each block.
 
   - post_cmd(): run right after the execution of each block.  If the block
     raises an exception, this is NOT called.
 
 
 Operation
 ---------
 
 The file is run in its own empty namespace (though you can pass it a string of
 arguments as if in a command line environment, and it will see those as
 sys.argv).  But at each stop, the global IPython namespace is updated with the
 current internal demo namespace, so you can work interactively with the data
 accumulated so far.
 
 By default, each block of code is printed (with syntax highlighting) before
 executing it and you have to confirm execution.  This is intended to show the
 code to an audience first so you can discuss it, and only proceed with
 execution once you agree.  There are a few tags which allow you to modify this
 behavior.
 
 The supported tags are:
 
 # <demo> stop
 
   Defines block boundaries, the points where IPython stops execution of the
   file and returns to the interactive prompt.
 
   You can optionally mark the stop tag with extra dashes before and after the
   word 'stop', to help visually distinguish the blocks in a text editor:
 
   # <demo> --- stop ---
 
 
 # <demo> silent
 
   Make a block execute silently (and hence automatically).  Typically used in
   cases where you have some boilerplate or initialization code which you need
   executed but do not want to be seen in the demo.
 
 # <demo> auto
 
   Make a block execute automatically, but still being printed.  Useful for
   simple code which does not warrant discussion, since it avoids the extra
   manual confirmation.
 
 # <demo> auto_all
 
   This tag can _only_ be in the first block, and if given it overrides the
   individual auto tags to make the whole demo fully automatic (no block asks
   for confirmation).  It can also be given at creation time (or the attribute
   set later) to override what's in the file.
 
 While _any_ python file can be run as a Demo instance, if there are no stop
 tags the whole file will run in a single block (no different that calling
 first %pycat and then %run).  The minimal markup to make this useful is to
 place a set of stop tags; the other tags are only there to let you fine-tune
 the execution.
 
 This is probably best explained with the simple example file below.  You can
 copy this into a file named ex_demo.py, and try running it via::
 
     from IPython.demo import Demo
     d = Demo('ex_demo.py')
     d()
 
 Each time you call the demo object, it runs the next block.  The demo object
 has a few useful methods for navigation, like again(), edit(), jump(), seek()
 and back().  It can be reset for a new run via reset() or reloaded from disk
 (in case you've edited the source) via reload().  See their docstrings below.
 
 Note: To make this simpler to explore, a file called "demo-exercizer.py" has
 been added to the "docs/examples/core" directory.  Just cd to this directory in
 an IPython session, and type::
 
   %run demo-exercizer.py
 
 and then follow the directions.
 
 Example
 -------
 
 The following is a very simple example of a valid demo file.
 
 ::
 
     #################### EXAMPLE DEMO <ex_demo.py> ###############################
     '''A simple interactive demo to illustrate the use of IPython's Demo class.'''
 
     print 'Hello, welcome to an interactive IPython demo.'
 
     # The mark below defines a block boundary, which is a point where IPython will
     # stop execution and return to the interactive prompt. The dashes are actually
     # optional and used only as a visual aid to clearly separate blocks while
     # editing the demo code.
     # <demo> stop
 
     x = 1
     y = 2
 
     # <demo> stop
 
     # the mark below makes this block as silent
     # <demo> silent
 
     print 'This is a silent block, which gets executed but not printed.'
 
     # <demo> stop
     # <demo> auto
     print 'This is an automatic block.'
     print 'It is executed without asking for confirmation, but printed.'
     z = x+y
 
     print 'z=',x
 
     # <demo> stop
     # This is just another normal block.
     print 'z is now:', z
 
     print 'bye!'
     ################### END EXAMPLE DEMO <ex_demo.py> ############################
 """
 
 from __future__ import unicode_literals
 
 #*****************************************************************************
 #     Copyright (C) 2005-2006 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #
 #*****************************************************************************
 from __future__ import print_function
 
 import os
 import re
 import shlex
 import sys
 
 from IPython.utils import io
-from IPython.utils.io import file_read
 from IPython.utils.text import marquee
 from IPython.utils import openpy
 __all__ = ['Demo','IPythonDemo','LineDemo','IPythonLineDemo','DemoError']
 
 class DemoError(Exception): pass
 
 def re_mark(mark):
     return re.compile(r'^\s*#\s+<demo>\s+%s\s*$' % mark,re.MULTILINE)
 
 class Demo(object):
 
     re_stop     = re_mark('-*\s?stop\s?-*')
     re_silent   = re_mark('silent')
     re_auto     = re_mark('auto')
     re_auto_all = re_mark('auto_all')
 
     def __init__(self,src,title='',arg_str='',auto_all=None):
         """Make a new demo object.  To run the demo, simply call the object.
 
         See the module docstring for full details and an example (you can use
         IPython.Demo? in IPython to see it).
 
         Inputs:
 
           - src is either a file, or file-like object, or a
               string that can be resolved to a filename.
 
         Optional inputs:
 
           - title: a string to use as the demo name.  Of most use when the demo
           you are making comes from an object that has no filename, or if you
           want an alternate denotation distinct from the filename.
 
           - arg_str(''): a string of arguments, internally converted to a list
           just like sys.argv, so the demo script can see a similar
           environment.
 
           - auto_all(None): global flag to run all blocks automatically without
           confirmation.  This attribute overrides the block-level tags and
           applies to the whole demo.  It is an attribute of the object, and
           can be changed at runtime simply by reassigning it to a boolean
           value.
           """
         if hasattr(src, "read"):
              # It seems to be a file or a file-like object
             self.fname = "from a file-like object"
             if title == '':
                 self.title = "from a file-like object"
             else:
                 self.title = title
         else:
              # Assume it's a string or something that can be converted to one
             self.fname = src
             if title == '':
                 (filepath, filename) = os.path.split(src)
                 self.title = filename
             else:
                 self.title = title
         self.sys_argv = [src] + shlex.split(arg_str)
         self.auto_all = auto_all
         self.src = src
 
         # get a few things from ipython.  While it's a bit ugly design-wise,
         # it ensures that things like color scheme and the like are always in
         # sync with the ipython mode being used.  This class is only meant to
         # be used inside ipython anyways,  so it's OK.
         ip = get_ipython()  # this is in builtins whenever IPython is running
         self.ip_ns       = ip.user_ns
         self.ip_colorize = ip.pycolorize
         self.ip_showtb   = ip.showtraceback
         self.ip_run_cell = ip.run_cell
         self.shell       = ip
 
         # load user data and initialize data structures
         self.reload()
 
     def fload(self):
         """Load file object."""
         # read data and parse into blocks
         if hasattr(self, 'fobj') and self.fobj is not None:
            self.fobj.close()
         if hasattr(self.src, "read"):
              # It seems to be a file or a file-like object
             self.fobj = self.src
         else:
              # Assume it's a string or something that can be converted to one
             self.fobj = openpy.open(self.fname)
 
     def reload(self):
         """Reload source from disk and initialize state."""
         self.fload()
 
         self.src     = "".join(openpy.strip_encoding_cookie(self.fobj))
         src_b        = [b.strip() for b in self.re_stop.split(self.src) if b]
         self._silent = [bool(self.re_silent.findall(b)) for b in src_b]
         self._auto   = [bool(self.re_auto.findall(b)) for b in src_b]
 
         # if auto_all is not given (def. None), we read it from the file
         if self.auto_all is None:
             self.auto_all = bool(self.re_auto_all.findall(src_b[0]))
         else:
             self.auto_all = bool(self.auto_all)
 
         # Clean the sources from all markup so it doesn't get displayed when
         # running the demo
         src_blocks = []
         auto_strip = lambda s: self.re_auto.sub('',s)
         for i,b in enumerate(src_b):
             if self._auto[i]:
                 src_blocks.append(auto_strip(b))
             else:
                 src_blocks.append(b)
         # remove the auto_all marker
         src_blocks[0] = self.re_auto_all.sub('',src_blocks[0])
 
         self.nblocks = len(src_blocks)
         self.src_blocks = src_blocks
 
         # also build syntax-highlighted source
         self.src_blocks_colored = map(self.ip_colorize,self.src_blocks)
 
         # ensure clean namespace and seek offset
         self.reset()
 
     def reset(self):
         """Reset the namespace and seek pointer to restart the demo"""
         self.user_ns     = {}
         self.finished    = False
         self.block_index = 0
 
     def _validate_index(self,index):
         if index<0 or index>=self.nblocks:
             raise ValueError('invalid block index %s' % index)
 
     def _get_index(self,index):
         """Get the current block index, validating and checking status.
 
         Returns None if the demo is finished"""
 
         if index is None:
             if self.finished:
                 print('Demo finished.  Use <demo_name>.reset() if you want to rerun it.', file=io.stdout)
                 return None
             index = self.block_index
         else:
             self._validate_index(index)
         return index
 
     def seek(self,index):
         """Move the current seek pointer to the given block.
 
         You can use negative indices to seek from the end, with identical
         semantics to those of Python lists."""
         if index<0:
             index = self.nblocks + index
         self._validate_index(index)
         self.block_index = index
         self.finished = False
 
     def back(self,num=1):
         """Move the seek pointer back num blocks (default is 1)."""
         self.seek(self.block_index-num)
 
     def jump(self,num=1):
         """Jump a given number of blocks relative to the current one.
 
         The offset can be positive or negative, defaults to 1."""
         self.seek(self.block_index+num)
 
     def again(self):
         """Move the seek pointer back one block and re-execute."""
         self.back(1)
         self()
 
     def edit(self,index=None):
         """Edit a block.
 
         If no number is given, use the last block executed.
 
         This edits the in-memory copy of the demo, it does NOT modify the
         original source file.  If you want to do that, simply open the file in
         an editor and use reload() when you make changes to the file.  This
         method is meant to let you change a block during a demonstration for
         explanatory purposes, without damaging your original script."""
 
         index = self._get_index(index)
         if index is None:
             return
         # decrease the index by one (unless we're at the very beginning), so
         # that the default demo.edit() call opens up the sblock we've last run
         if index>0:
             index -= 1
 
         filename = self.shell.mktempfile(self.src_blocks[index])
         self.shell.hooks.editor(filename,1)
-        new_block = file_read(filename)
+        with open(filename, 'r') as f:
+            new_block = f.read()
         # update the source and colored block
         self.src_blocks[index] = new_block
         self.src_blocks_colored[index] = self.ip_colorize(new_block)
         self.block_index = index
         # call to run with the newly edited index
         self()
 
     def show(self,index=None):
         """Show a single block on screen"""
 
         index = self._get_index(index)
         if index is None:
             return
 
         print(self.marquee('<%s> block # %s (%s remaining)' %
                            (self.title,index,self.nblocks-index-1)), file=io.stdout)
         print((self.src_blocks_colored[index]), file=io.stdout)
         sys.stdout.flush()
 
     def show_all(self):
         """Show entire demo on screen, block by block"""
 
         fname = self.title
         title = self.title
         nblocks = self.nblocks
         silent = self._silent
         marquee = self.marquee
         for index,block in enumerate(self.src_blocks_colored):
             if silent[index]:
                 print(marquee('<%s> SILENT block # %s (%s remaining)' %
                               (title,index,nblocks-index-1)), file=io.stdout)
             else:
                 print(marquee('<%s> block # %s (%s remaining)' %
                               (title,index,nblocks-index-1)), file=io.stdout)
             print(block, end=' ', file=io.stdout)
         sys.stdout.flush()
 
     def run_cell(self,source):
         """Execute a string with one or more lines of code"""
 
         exec source in self.user_ns
 
     def __call__(self,index=None):
         """run a block of the demo.
 
         If index is given, it should be an integer >=1 and <= nblocks.  This
         means that the calling convention is one off from typical Python
         lists.  The reason for the inconsistency is that the demo always
         prints 'Block n/N, and N is the total, so it would be very odd to use
         zero-indexing here."""
 
         index = self._get_index(index)
         if index is None:
             return
         try:
             marquee = self.marquee
             next_block = self.src_blocks[index]
             self.block_index += 1
             if self._silent[index]:
                 print(marquee('Executing silent block # %s (%s remaining)' %
                               (index,self.nblocks-index-1)), file=io.stdout)
             else:
                 self.pre_cmd()
                 self.show(index)
                 if self.auto_all or self._auto[index]:
                     print(marquee('output:'), file=io.stdout)
                 else:
                     print(marquee('Press <q> to quit, <Enter> to execute...'), end=' ', file=io.stdout)
                     ans = raw_input().strip()
                     if ans:
                         print(marquee('Block NOT executed'), file=io.stdout)
                         return
             try:
                 save_argv = sys.argv
                 sys.argv = self.sys_argv
                 self.run_cell(next_block)
                 self.post_cmd()
             finally:
                 sys.argv = save_argv
 
         except:
             self.ip_showtb(filename=self.fname)
         else:
             self.ip_ns.update(self.user_ns)
 
         if self.block_index == self.nblocks:
             mq1 = self.marquee('END OF DEMO')
             if mq1:
                 # avoid spurious print >>io.stdout,s if empty marquees are used
                 print(file=io.stdout)
                 print(mq1, file=io.stdout)
                 print(self.marquee('Use <demo_name>.reset() if you want to rerun it.'), file=io.stdout)
             self.finished = True
 
     # These methods are meant to be overridden by subclasses who may wish to
     # customize the behavior of of their demos.
     def marquee(self,txt='',width=78,mark='*'):
         """Return the input string centered in a 'marquee'."""
         return marquee(txt,width,mark)
 
     def pre_cmd(self):
         """Method called before executing each block."""
         pass
 
     def post_cmd(self):
         """Method called after executing each block."""
         pass
 
 
 class IPythonDemo(Demo):
     """Class for interactive demos with IPython's input processing applied.
 
     This subclasses Demo, but instead of executing each block by the Python
     interpreter (via exec), it actually calls IPython on it, so that any input
     filters which may be in place are applied to the input block.
 
     If you have an interactive environment which exposes special input
     processing, you can use this class instead to write demo scripts which
     operate exactly as if you had typed them interactively.  The default Demo
     class requires the input to be valid, pure Python code.
     """
 
     def run_cell(self,source):
         """Execute a string with one or more lines of code"""
 
         self.shell.run_cell(source)
 
 class LineDemo(Demo):
     """Demo where each line is executed as a separate block.
 
     The input script should be valid Python code.
 
     This class doesn't require any markup at all, and it's meant for simple
     scripts (with no nesting or any kind of indentation) which consist of
     multiple lines of input to be executed, one at a time, as if they had been
     typed in the interactive prompt.
 
     Note: the input can not have *any* indentation, which means that only
     single-lines of input are accepted, not even function definitions are
     valid."""
 
     def reload(self):
         """Reload source from disk and initialize state."""
         # read data and parse into blocks
         self.fload()
         lines           = self.fobj.readlines()
         src_b           = [l for l in lines if l.strip()]
         nblocks         = len(src_b)
         self.src        = ''.join(lines)
         self._silent    = [False]*nblocks
         self._auto      = [True]*nblocks
         self.auto_all   = True
         self.nblocks    = nblocks
         self.src_blocks = src_b
 
         # also build syntax-highlighted source
         self.src_blocks_colored = map(self.ip_colorize,self.src_blocks)
 
         # ensure clean namespace and seek offset
         self.reset()
 
 
 class IPythonLineDemo(IPythonDemo,LineDemo):
     """Variant of the LineDemo class whose input is processed by IPython."""
     pass
 
 
 class ClearMixin(object):
     """Use this mixin to make Demo classes with less visual clutter.
 
     Demos using this mixin will clear the screen before every block and use
     blank marquees.
 
     Note that in order for the methods defined here to actually override those
     of the classes it's mixed with, it must go /first/ in the inheritance
     tree.  For example:
 
         class ClearIPDemo(ClearMixin,IPythonDemo): pass
 
     will provide an IPythonDemo class with the mixin's features.
     """
 
     def marquee(self,txt='',width=78,mark='*'):
         """Blank marquee that returns '' no matter what the input."""
         return ''
 
     def pre_cmd(self):
         """Method called before executing each block.
 
         This one simply clears the screen."""
         from IPython.utils.terminal import term_clear
         term_clear()
 
 class ClearDemo(ClearMixin,Demo):
     pass
 
 
 class ClearIPDemo(ClearMixin,IPythonDemo):
     pass

IPython/utils/_process_posix.py

@@ -1,197 +1,198
 """Posix-specific implementation of process utilities.
 
 This file is only meant to be imported by process.py, not by end-users.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib
 import subprocess as sp
 import sys
 
 from IPython.external import pexpect
 
 # Our own
-from .autoattr import auto_attr
 from ._process_common import getoutput, arg_split
 from IPython.utils import py3compat
 from IPython.utils.encoding import DEFAULT_ENCODING
 
 #-----------------------------------------------------------------------------
 # Function definitions
 #-----------------------------------------------------------------------------
 
 def _find_cmd(cmd):
     """Find the full path to a command using which."""
 
     path = sp.Popen(['/usr/bin/env', 'which', cmd],
                     stdout=sp.PIPE, stderr=sp.PIPE).communicate()[0]
     return py3compat.bytes_to_str(path)
 
 
 class ProcessHandler(object):
     """Execute subprocesses under the control of pexpect.
     """
     # Timeout in seconds to wait on each reading of the subprocess' output.
     # This should not be set too low to avoid cpu overusage from our side,
     # since we read in a loop whose period is controlled by this timeout.
     read_timeout = 0.05
 
     # Timeout to give a process if we receive SIGINT, between sending the
     # SIGINT to the process and forcefully terminating it.
     terminate_timeout = 0.2
 
     # File object where stdout and stderr of the subprocess will be written
     logfile = None
 
     # Shell to call for subprocesses to execute
-    sh = None
+    _sh = None
 
-    @auto_attr
+    @property
     def sh(self):
-        sh = pexpect.which('sh')
-        if sh is None:
+        if self._sh is None:        
+            self._sh = pexpect.which('sh')
+            if self._sh is None:
             raise OSError('"sh" shell not found')
-        return sh
+        
+        return self._sh
 
     def __init__(self, logfile=None, read_timeout=None, terminate_timeout=None):
         """Arguments are used for pexpect calls."""
         self.read_timeout = (ProcessHandler.read_timeout if read_timeout is
                              None else read_timeout)
         self.terminate_timeout = (ProcessHandler.terminate_timeout if
                                   terminate_timeout is None else
                                   terminate_timeout)
         self.logfile = sys.stdout if logfile is None else logfile
 
     def getoutput(self, cmd):
         """Run a command and return its stdout/stderr as a string.
 
         Parameters
         ----------
         cmd : str
           A command to be executed in the system shell.
 
         Returns
         -------
         output : str
           A string containing the combination of stdout and stderr from the
         subprocess, in whatever order the subprocess originally wrote to its
         file descriptors (so the order of the information in this string is the
         correct order as would be seen if running the command in a terminal).
         """
         try:
             return pexpect.run(self.sh, args=['-c', cmd]).replace('\r\n', '\n')
         except KeyboardInterrupt:
             print('^C', file=sys.stderr, end='')
 
     def getoutput_pexpect(self, cmd):
         """Run a command and return its stdout/stderr as a string.
 
         Parameters
         ----------
         cmd : str
           A command to be executed in the system shell.
 
         Returns
         -------
         output : str
           A string containing the combination of stdout and stderr from the
         subprocess, in whatever order the subprocess originally wrote to its
         file descriptors (so the order of the information in this string is the
         correct order as would be seen if running the command in a terminal).
         """
         try:
             return pexpect.run(self.sh, args=['-c', cmd]).replace('\r\n', '\n')
         except KeyboardInterrupt:
             print('^C', file=sys.stderr, end='')
 
     def system(self, cmd):
         """Execute a command in a subshell.
 
         Parameters
         ----------
         cmd : str
           A command to be executed in the system shell.
 
         Returns
         -------
         int : child's exitstatus
         """
         # Get likely encoding for the output.
         enc = DEFAULT_ENCODING
         
         # Patterns to match on the output, for pexpect.  We read input and
         # allow either a short timeout or EOF
         patterns = [pexpect.TIMEOUT, pexpect.EOF]
         # the index of the EOF pattern in the list.
         # even though we know it's 1, this call means we don't have to worry if
         # we change the above list, and forget to change this value:
         EOF_index = patterns.index(pexpect.EOF)
         # The size of the output stored so far in the process output buffer.
         # Since pexpect only appends to this buffer, each time we print we
         # record how far we've printed, so that next time we only print *new*
         # content from the buffer.
         out_size = 0
         try:
             # Since we're not really searching the buffer for text patterns, we
             # can set pexpect's search window to be tiny and it won't matter.
             # We only search for the 'patterns' timeout or EOF, which aren't in
             # the text itself.
             #child = pexpect.spawn(pcmd, searchwindowsize=1)
             if hasattr(pexpect, 'spawnb'):
                 child = pexpect.spawnb(self.sh, args=['-c', cmd]) # Pexpect-U
             else:
                 child = pexpect.spawn(self.sh, args=['-c', cmd])  # Vanilla Pexpect
             flush = sys.stdout.flush
             while True:
                 # res is the index of the pattern that caused the match, so we
                 # know whether we've finished (if we matched EOF) or not
                 res_idx = child.expect_list(patterns, self.read_timeout)
                 print(child.before[out_size:].decode(enc, 'replace'), end='')
                 flush()
                 if res_idx==EOF_index:
                     break
                 # Update the pointer to what we've already printed
                 out_size = len(child.before)
         except KeyboardInterrupt:
             # We need to send ^C to the process.  The ascii code for '^C' is 3
             # (the character is known as ETX for 'End of Text', see
             # curses.ascii.ETX).
             child.sendline(chr(3))
             # Read and print any more output the program might produce on its
             # way out.
             try:
                 out_size = len(child.before)
                 child.expect_list(patterns, self.terminate_timeout)
                 print(child.before[out_size:].decode(enc, 'replace'), end='')
                 sys.stdout.flush()
             except KeyboardInterrupt:
                 # Impatient users tend to type it multiple times
                 pass
             finally:
                 # Ensure the subprocess really is terminated
                 child.terminate(force=True)
         # add isalive check, to ensure exitstatus is set:
         child.isalive()
         return child.exitstatus
 
 
 # Make system() with a functional interface for outside use.  Note that we use
 # getoutput() from the _common utils, which is built on top of popen(). Using
 # pexpect to get subprocess output produces difficult to parse output, since
 # programs think they are talking to a tty and produce highly formatted output
 # (ls is a good example) that makes them hard.
 system = ProcessHandler().system
 
 
 

IPython/utils/data.py

@@ -1,96 +1,35
 # encoding: utf-8
 """Utilities for working with data structures like lists, dicts and tuples.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
-
-import types
-
-#-----------------------------------------------------------------------------
-# Code
-#-----------------------------------------------------------------------------
-
 def uniq_stable(elems):
     """uniq_stable(elems) -> list
 
     Return from an iterable, a list of all the unique elements in the input,
     but maintaining the order in which they first appear.
 
     Note: All elements in the input must be hashable for this routine
     to work, as it internally uses a set for efficiency reasons.
     """
     seen = set()
     return [x for x in elems if x not in seen and not seen.add(x)]
 
 
-def sort_compare(lst1, lst2, inplace=1):
-    """Sort and compare two lists.
-
-    By default it does it in place, thus modifying the lists. Use inplace = 0
-    to avoid that (at the cost of temporary copy creation)."""
-    if not inplace:
-        lst1 = lst1[:]
-        lst2 = lst2[:]
-    lst1.sort(); lst2.sort()
-    return lst1 == lst2
-
-
-def list2dict(lst):
-    """Takes a list of (key,value) pairs and turns it into a dict."""
-
-    dic = {}
-    for k,v in lst: dic[k] = v
-    return dic
-
-
-def list2dict2(lst, default=''):
-    """Takes a list and turns it into a dict.
-    Much slower than list2dict, but more versatile. This version can take
-    lists with sublists of arbitrary length (including sclars)."""
-
-    dic = {}
-    for elem in lst:
-        if type(elem) in (types.ListType,types.TupleType):
-            size = len(elem)
-            if  size == 0:
-                pass
-            elif size == 1:
-                dic[elem] = default
-            else:
-                k,v = elem[0], elem[1:]
-                if len(v) == 1: v = v[0]
-                dic[k] = v
-        else:
-            dic[elem] = default
-    return dic
-
-
 def flatten(seq):
     """Flatten a list of lists (NOT recursive, only works for 2d lists)."""
 
     return [x for subseq in seq for x in subseq]
 
 
-def get_slice(seq, start=0, stop=None, step=1):
-    """Get a slice of a sequence with variable step. Specify start,stop,step."""
-    if stop == None:
-        stop = len(seq)
-    item = lambda i: seq[i]
-    return map(item,xrange(start,stop,step))
-
-
 def chop(seq, size):
     """Chop a sequence into chunks of the given size."""
-    chunk = lambda i: seq[i:i+size]
-    return map(chunk,xrange(0,len(seq),size))
+    return [seq[i:i+size] for i in xrange(0,len(seq),size)]
 
 

IPython/utils/io.py

@@ -1,384 +1,288
 # encoding: utf-8
 """
 IO related utilities.
 """
 
 #-----------------------------------------------------------------------------
 #  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.
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 import os
 import sys
 import tempfile
 from StringIO import StringIO
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 class IOStream:
 
     def __init__(self,stream, fallback=None):
         if not hasattr(stream,'write') or not hasattr(stream,'flush'):
             if fallback is not None:
                 stream = fallback
             else:
                 raise ValueError("fallback required, but not specified")
         self.stream = stream
         self._swrite = stream.write
 
         # clone all methods not overridden:
         def clone(meth):
             return not hasattr(self, meth) and not meth.startswith('_')
         for meth in filter(clone, dir(stream)):
             setattr(self, meth, getattr(stream, meth))
 
     def write(self,data):
         try:
             self._swrite(data)
         except:
             try:
                 # print handles some unicode issues which may trip a plain
                 # write() call.  Emulate write() by using an empty end
                 # argument.
                 print(data, end='', file=self.stream)
             except:
                 # if we get here, something is seriously broken.
                 print('ERROR - failed to write data to stream:', self.stream,
                       file=sys.stderr)
 
     def writelines(self, lines):
         if isinstance(lines, basestring):
             lines = [lines]
         for line in lines:
             self.write(line)
 
     # This class used to have a writeln method, but regular files and streams
     # in Python don't have this method. We need to keep this completely
     # compatible so we removed it.
 
     @property
     def closed(self):
         return self.stream.closed
 
     def close(self):
         pass
 
 # setup stdin/stdout/stderr to sys.stdin/sys.stdout/sys.stderr
 devnull = open(os.devnull, 'a')
 stdin = IOStream(sys.stdin, fallback=devnull)
 stdout = IOStream(sys.stdout, fallback=devnull)
 stderr = IOStream(sys.stderr, fallback=devnull)
 
 class IOTerm:
     """ Term holds the file or file-like objects for handling I/O operations.
 
     These are normally just sys.stdin, sys.stdout and sys.stderr but for
     Windows they can can replaced to allow editing the strings before they are
     displayed."""
 
     # In the future, having IPython channel all its I/O operations through
     # this class will make it easier to embed it into other environments which
     # are not a normal terminal (such as a GUI-based shell)
     def __init__(self, stdin=None, stdout=None, stderr=None):
         mymodule = sys.modules[__name__]
         self.stdin  = IOStream(stdin, mymodule.stdin)
         self.stdout = IOStream(stdout, mymodule.stdout)
         self.stderr = IOStream(stderr, mymodule.stderr)
 
 
 class Tee(object):
     """A class to duplicate an output stream to stdout/err.
 
     This works in a manner very similar to the Unix 'tee' command.
 
     When the object is closed or deleted, it closes the original file given to
     it for duplication.
     """
     # Inspired by:
     # http://mail.python.org/pipermail/python-list/2007-May/442737.html
 
     def __init__(self, file_or_name, mode="w", channel='stdout'):
         """Construct a new Tee object.
 
         Parameters
         ----------
         file_or_name : filename or open filehandle (writable)
           File that will be duplicated
 
         mode : optional, valid mode for open().
           If a filename was give, open with this mode.
 
         channel : str, one of ['stdout', 'stderr']
         """
         if channel not in ['stdout', 'stderr']:
             raise ValueError('Invalid channel spec %s' % channel)
 
         if hasattr(file_or_name, 'write') and hasattr(file_or_name, 'seek'):
             self.file = file_or_name
         else:
             self.file = open(file_or_name, mode)
         self.channel = channel
         self.ostream = getattr(sys, channel)
         setattr(sys, channel, self)
         self._closed = False
 
     def close(self):
         """Close the file and restore the channel."""
         self.flush()
         setattr(sys, self.channel, self.ostream)
         self.file.close()
         self._closed = True
 
     def write(self, data):
         """Write data to both channels."""
         self.file.write(data)
         self.ostream.write(data)
         self.ostream.flush()
 
     def flush(self):
         """Flush both channels."""
         self.file.flush()
         self.ostream.flush()
 
     def __del__(self):
         if not self._closed:
             self.close()
 
 
-def file_read(filename):
-    """Read a file and close it.  Returns the file source."""
-    fobj = open(filename,'r');
-    source = fobj.read();
-    fobj.close()
-    return source
-
-
-def file_readlines(filename):
-    """Read a file and close it.  Returns the file source using readlines()."""
-    fobj = open(filename,'r');
-    lines = fobj.readlines();
-    fobj.close()
-    return lines
-
-
-def raw_input_multi(header='', ps1='==> ', ps2='..> ',terminate_str = '.'):
-    """Take multiple lines of input.
-
-    A list with each line of input as a separate element is returned when a
-    termination string is entered (defaults to a single '.'). Input can also
-    terminate via EOF (^D in Unix, ^Z-RET in Windows).
-
-    Lines of input which end in \\ are joined into single entries (and a
-    secondary continuation prompt is issued as long as the user terminates
-    lines with \\). This allows entering very long strings which are still
-    meant to be treated as single entities.
-    """
-
-    try:
-        if header:
-            header += '\n'
-        lines = [raw_input(header + ps1)]
-    except EOFError:
-        return []
-    terminate = [terminate_str]
-    try:
-        while lines[-1:] != terminate:
-            new_line = raw_input(ps1)
-            while new_line.endswith('\\'):
-                new_line = new_line[:-1] + raw_input(ps2)
-            lines.append(new_line)
-
-        return lines[:-1]  # don't return the termination command
-    except EOFError:
-        print()
-        return lines
-
-
-def raw_input_ext(prompt='',  ps2='... '):
-    """Similar to raw_input(), but accepts extended lines if input ends with \\."""
-
-    line = raw_input(prompt)
-    while line.endswith('\\'):
-        line = line[:-1] + raw_input(ps2)
-    return line
-
-
 def ask_yes_no(prompt,default=None):
     """Asks a question and returns a boolean (y/n) answer.
 
     If default is given (one of 'y','n'), it is used if the user input is
     empty. Otherwise the question is repeated until an answer is given.
 
     An EOF is treated as the default answer.  If there is no default, an
     exception is raised to prevent infinite loops.
 
     Valid answers are: y/yes/n/no (match is not case sensitive)."""
 
     answers = {'y':True,'n':False,'yes':True,'no':False}
     ans = None
     while ans not in answers.keys():
         try:
             ans = raw_input(prompt+' ').lower()
             if not ans:  # response was an empty string
                 ans = default
         except KeyboardInterrupt:
             pass
         except EOFError:
             if default in answers.keys():
                 ans = default
                 print()
             else:
                 raise
 
     return answers[ans]
 
 
-class NLprinter:
-    """Print an arbitrarily nested list, indicating index numbers.
-
-    An instance of this class called nlprint is available and callable as a
-    function.
-
-    nlprint(list,indent=' ',sep=': ') -> prints indenting each level by 'indent'
-    and using 'sep' to separate the index from the value. """
-
-    def __init__(self):
-        self.depth = 0
-
-    def __call__(self,lst,pos='',**kw):
-        """Prints the nested list numbering levels."""
-        kw.setdefault('indent',' ')
-        kw.setdefault('sep',': ')
-        kw.setdefault('start',0)
-        kw.setdefault('stop',len(lst))
-        # we need to remove start and stop from kw so they don't propagate
-        # into a recursive call for a nested list.
-        start = kw['start']; del kw['start']
-        stop = kw['stop']; del kw['stop']
-        if self.depth == 0 and 'header' in kw.keys():
-            print(kw['header'])
-
-        for idx in range(start,stop):
-            elem = lst[idx]
-            newpos = pos + str(idx)
-            if type(elem)==type([]):
-                self.depth += 1
-                self.__call__(elem, newpos+",", **kw)
-                self.depth -= 1
-            else:
-                print(kw['indent']*self.depth + newpos + kw["sep"] + repr(elem))
-
-nlprint = NLprinter()
-
-
 def temp_pyfile(src, ext='.py'):
     """Make a temporary python file, return filename and filehandle.
 
     Parameters
     ----------
     src : string or list of strings (no need for ending newlines if list)
       Source code to be written to the file.
 
     ext : optional, string
       Extension for the generated file.
 
     Returns
     -------
     (filename, open filehandle)
       It is the caller's responsibility to close the open file and unlink it.
     """
     fname = tempfile.mkstemp(ext)[1]
     f = open(fname,'w')
     f.write(src)
     f.flush()
     return fname, f
 
 
 def raw_print(*args, **kw):
     """Raw print to sys.__stdout__, otherwise identical interface to print()."""
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stdout__)
     sys.__stdout__.flush()
 
 
 def raw_print_err(*args, **kw):
     """Raw print to sys.__stderr__, otherwise identical interface to print()."""
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stderr__)
     sys.__stderr__.flush()
 
 
 # Short aliases for quick debugging, do NOT use these in production code.
 rprint = raw_print
 rprinte = raw_print_err
 
 
 class CapturedIO(object):
     """Simple object for containing captured stdout/err StringIO objects"""
     
     def __init__(self, stdout, stderr):
         self._stdout = stdout
         self._stderr = stderr
     
     def __str__(self):
         return self.stdout
     
     @property
     def stdout(self):
         if not self._stdout:
             return ''
         return self._stdout.getvalue()
     
     @property
     def stderr(self):
         if not self._stderr:
             return ''
         return self._stderr.getvalue()
     
     def show(self):
         """write my output to sys.stdout/err as appropriate"""
         sys.stdout.write(self.stdout)
         sys.stderr.write(self.stderr)
         sys.stdout.flush()
         sys.stderr.flush()
     
     __call__ = show
 
 
 class capture_output(object):
     """context manager for capturing stdout/err"""
     stdout = True
     stderr = True
     
     def __init__(self, stdout=True, stderr=True):
         self.stdout = stdout
         self.stderr = stderr
     
     def __enter__(self):
         self.sys_stdout = sys.stdout
         self.sys_stderr = sys.stderr
         
         stdout = stderr = False
         if self.stdout:
             stdout = sys.stdout = StringIO()
         if self.stderr:
             stderr = sys.stderr = StringIO()
         
         return CapturedIO(stdout, stderr)
     
     def __exit__(self, exc_type, exc_value, traceback):
         sys.stdout = self.sys_stdout
         sys.stderr = self.sys_stderr
 
 

IPython/utils/ipstruct.py

@@ -1,393 +1,391
 # encoding: utf-8
 """A dict subclass that supports attribute style access.
 
 Authors:
 
 * Fernando Perez (original)
 * Brian Granger (refactoring to a dict subclass)
 """
 
 #-----------------------------------------------------------------------------
 #  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 IPython.utils.data import list2dict2
-
 __all__ = ['Struct']
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 class Struct(dict):
     """A dict subclass with attribute style access.
 
     This dict subclass has a a few extra features:
 
     * Attribute style access.
     * Protection of class members (like keys, items) when using attribute
       style access.
     * The ability to restrict assignment to only existing keys.
     * Intelligent merging.
     * Overloaded operators.
     """
     _allownew = True
     def __init__(self, *args, **kw):
         """Initialize with a dictionary, another Struct, or data.
 
         Parameters
         ----------
         args : dict, Struct
             Initialize with one dict or Struct
         kw : dict
             Initialize with key, value pairs.
 
         Examples
         --------
 
         >>> s = Struct(a=10,b=30)
         >>> s.a
         10
         >>> s.b
         30
         >>> s2 = Struct(s,c=30)
         >>> sorted(s2.keys())
         ['a', 'b', 'c']
         """
         object.__setattr__(self, '_allownew', True)
         dict.__init__(self, *args, **kw)
 
     def __setitem__(self, key, value):
         """Set an item with check for allownew.
 
         Examples
         --------
 
         >>> s = Struct()
         >>> s['a'] = 10
         >>> s.allow_new_attr(False)
         >>> s['a'] = 10
         >>> s['a']
         10
         >>> try:
         ...     s['b'] = 20
         ... except KeyError:
         ...     print 'this is not allowed'
         ...
         this is not allowed
         """
         if not self._allownew and key not in self:
             raise KeyError(
                 "can't create new attribute %s when allow_new_attr(False)" % key)
         dict.__setitem__(self, key, value)
 
     def __setattr__(self, key, value):
         """Set an attr with protection of class members.
 
         This calls :meth:`self.__setitem__` but convert :exc:`KeyError` to
         :exc:`AttributeError`.
 
         Examples
         --------
 
         >>> s = Struct()
         >>> s.a = 10
         >>> s.a
         10
         >>> try:
         ...     s.get = 10
         ... except AttributeError:
         ...     print "you can't set a class member"
         ...
         you can't set a class member
         """
         # If key is an str it might be a class member or instance var
         if isinstance(key, str):
             # I can't simply call hasattr here because it calls getattr, which
             # calls self.__getattr__, which returns True for keys in
             # self._data.  But I only want keys in the class and in
             # self.__dict__
             if key in self.__dict__ or hasattr(Struct, key):
                 raise AttributeError(
                     'attr %s is a protected member of class Struct.' % key
                 )
         try:
             self.__setitem__(key, value)
         except KeyError as e:
             raise AttributeError(e)
 
     def __getattr__(self, key):
         """Get an attr by calling :meth:`dict.__getitem__`.
 
         Like :meth:`__setattr__`, this method converts :exc:`KeyError` to
         :exc:`AttributeError`.
 
         Examples
         --------
 
         >>> s = Struct(a=10)
         >>> s.a
         10
         >>> type(s.get)
         <... 'builtin_function_or_method'>
         >>> try:
         ...     s.b
         ... except AttributeError:
         ...     print "I don't have that key"
         ...
         I don't have that key
         """
         try:
             result = self[key]
         except KeyError:
             raise AttributeError(key)
         else:
             return result
 
     def __iadd__(self, other):
         """s += s2 is a shorthand for s.merge(s2).
 
         Examples
         --------
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,c=40)
         >>> s += s2
         >>> sorted(s.keys())
         ['a', 'b', 'c']
         """
         self.merge(other)
         return self
 
     def __add__(self,other):
         """s + s2 -> New Struct made from s.merge(s2).
 
         Examples
         --------
 
         >>> s1 = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,c=40)
         >>> s = s1 + s2
         >>> sorted(s.keys())
         ['a', 'b', 'c']
         """
         sout = self.copy()
         sout.merge(other)
         return sout
 
     def __sub__(self,other):
         """s1 - s2 -> remove keys in s2 from s1.
 
         Examples
         --------
 
         >>> s1 = Struct(a=10,b=30)
         >>> s2 = Struct(a=40)
         >>> s = s1 - s2
         >>> s
         {'b': 30}
         """
         sout = self.copy()
         sout -= other
         return sout
 
     def __isub__(self,other):
         """Inplace remove keys from self that are in other.
 
         Examples
         --------
 
         >>> s1 = Struct(a=10,b=30)
         >>> s2 = Struct(a=40)
         >>> s1 -= s2
         >>> s1
         {'b': 30}
         """
         for k in other.keys():
             if k in self:
                 del self[k]
         return self
 
     def __dict_invert(self, data):
         """Helper function for merge.
 
         Takes a dictionary whose values are lists and returns a dict with
         the elements of each list as keys and the original keys as values.
         """
         outdict = {}
         for k,lst in data.items():
             if isinstance(lst, str):
                 lst = lst.split()
             for entry in lst:
                 outdict[entry] = k
         return outdict
 
     def dict(self):
         return self
 
     def copy(self):
         """Return a copy as a Struct.
 
         Examples
         --------
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = s.copy()
         >>> type(s2) is Struct
         True
         """
         return Struct(dict.copy(self))
 
     def hasattr(self, key):
         """hasattr function available as a method.
 
         Implemented like has_key.
 
         Examples
         --------
 
         >>> s = Struct(a=10)
         >>> s.hasattr('a')
         True
         >>> s.hasattr('b')
         False
         >>> s.hasattr('get')
         False
         """
         return key in self
 
     def allow_new_attr(self, allow = True):
         """Set whether new attributes can be created in this Struct.
 
         This can be used to catch typos by verifying that the attribute user
         tries to change already exists in this Struct.
         """
         object.__setattr__(self, '_allownew', allow)
 
     def merge(self, __loc_data__=None, __conflict_solve=None, **kw):
         """Merge two Structs with customizable conflict resolution.
 
         This is similar to :meth:`update`, but much more flexible. First, a
         dict is made from data+key=value pairs. When merging this dict with
         the Struct S, the optional dictionary 'conflict' is used to decide
         what to do.
 
         If conflict is not given, the default behavior is to preserve any keys
         with their current value (the opposite of the :meth:`update` method's
         behavior).
 
         Parameters
         ----------
         __loc_data : dict, Struct
             The data to merge into self
         __conflict_solve : dict
             The conflict policy dict.  The keys are binary functions used to
             resolve the conflict and the values are lists of strings naming
             the keys the conflict resolution function applies to.  Instead of
             a list of strings a space separated string can be used, like
             'a b c'.
         kw : dict
             Additional key, value pairs to merge in
 
         Notes
         -----
 
         The `__conflict_solve` dict is a dictionary of binary functions which will be used to
         solve key conflicts.  Here is an example::
 
             __conflict_solve = dict(
                 func1=['a','b','c'],
                 func2=['d','e']
             )
 
         In this case, the function :func:`func1` will be used to resolve
         keys 'a', 'b' and 'c' and the function :func:`func2` will be used for
         keys 'd' and 'e'.  This could also be written as::
 
             __conflict_solve = dict(func1='a b c',func2='d e')
 
         These functions will be called for each key they apply to with the
         form::
 
             func1(self['a'], other['a'])
 
         The return value is used as the final merged value.
 
         As a convenience, merge() provides five (the most commonly needed)
         pre-defined policies: preserve, update, add, add_flip and add_s. The
         easiest explanation is their implementation::
 
             preserve = lambda old,new: old
             update   = lambda old,new: new
             add      = lambda old,new: old + new
             add_flip = lambda old,new: new + old  # note change of order!
             add_s    = lambda old,new: old + ' ' + new  # only for str!
 
         You can use those four words (as strings) as keys instead
         of defining them as functions, and the merge method will substitute
         the appropriate functions for you.
 
         For more complicated conflict resolution policies, you still need to
         construct your own functions.
 
         Examples
         --------
 
         This show the default policy:
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,c=40)
         >>> s.merge(s2)
         >>> sorted(s.items())
         [('a', 10), ('b', 30), ('c', 40)]
 
         Now, show how to specify a conflict dict:
 
         >>> s = Struct(a=10,b=30)
         >>> s2 = Struct(a=20,b=40)
         >>> conflict = {'update':'a','add':'b'}
         >>> s.merge(s2,conflict)
         >>> sorted(s.items())
         [('a', 20), ('b', 70)]
         """
 
         data_dict = dict(__loc_data__,**kw)
 
         # policies for conflict resolution: two argument functions which return
         # the value that will go in the new struct
         preserve = lambda old,new: old
         update   = lambda old,new: new
         add      = lambda old,new: old + new
         add_flip = lambda old,new: new + old  # note change of order!
         add_s    = lambda old,new: old + ' ' + new
 
         # default policy is to keep current keys when there's a conflict
-        conflict_solve = list2dict2(self.keys(), default = preserve)
+        conflict_solve = dict.fromkeys(self, preserve)
 
         # the conflict_solve dictionary is given by the user 'inverted': we
         # need a name-function mapping, it comes as a function -> names
         # dict. Make a local copy (b/c we'll make changes), replace user
         # strings for the three builtin policies and invert it.
         if __conflict_solve:
             inv_conflict_solve_user = __conflict_solve.copy()
             for name, func in [('preserve',preserve), ('update',update),
                                ('add',add), ('add_flip',add_flip),
                                ('add_s',add_s)]:
                 if name in inv_conflict_solve_user.keys():
                     inv_conflict_solve_user[func] = inv_conflict_solve_user[name]
                     del inv_conflict_solve_user[name]
             conflict_solve.update(self.__dict_invert(inv_conflict_solve_user))
         for key in data_dict:
             if key not in self:
                 self[key] = data_dict[key]
             else:
                 self[key] = conflict_solve[key](self[key],data_dict[key])
 

IPython/utils/openpy.py

@@ -1,219 +1,239
 """
 Tools to open .py files as Unicode, using the encoding specified within the file,
 as per PEP 263.
 
 Much of the code is taken from the tokenize module in Python 3.2.
 """
 from __future__ import absolute_import
 
 import io
 from io import TextIOWrapper, BytesIO
+import os.path
 import re
 
 cookie_re = re.compile(ur"coding[:=]\s*([-\w.]+)", re.UNICODE)
 cookie_comment_re = re.compile(ur"^\s*#.*coding[:=]\s*([-\w.]+)", re.UNICODE)
 
 try:
     # Available in Python 3
     from tokenize import detect_encoding
 except ImportError:
     from codecs import lookup, BOM_UTF8
     
     # Copied from Python 3.2 tokenize
     def _get_normal_name(orig_enc):
         """Imitates get_normal_name in tokenizer.c."""
         # Only care about the first 12 characters.
         enc = orig_enc[:12].lower().replace("_", "-")
         if enc == "utf-8" or enc.startswith("utf-8-"):
             return "utf-8"
         if enc in ("latin-1", "iso-8859-1", "iso-latin-1") or \
            enc.startswith(("latin-1-", "iso-8859-1-", "iso-latin-1-")):
             return "iso-8859-1"
         return orig_enc
     
     # Copied from Python 3.2 tokenize
     def detect_encoding(readline):
         """
         The detect_encoding() function is used to detect the encoding that should
         be used to decode a Python source file.  It requires one argment, readline,
         in the same way as the tokenize() generator.
 
         It will call readline a maximum of twice, and return the encoding used
         (as a string) and a list of any lines (left as bytes) it has read in.
 
         It detects the encoding from the presence of a utf-8 bom or an encoding
         cookie as specified in pep-0263.  If both a bom and a cookie are present,
         but disagree, a SyntaxError will be raised.  If the encoding cookie is an
         invalid charset, raise a SyntaxError.  Note that if a utf-8 bom is found,
         'utf-8-sig' is returned.
 
         If no encoding is specified, then the default of 'utf-8' will be returned.
         """
         bom_found = False
         encoding = None
         default = 'utf-8'
         def read_or_stop():
             try:
                 return readline()
             except StopIteration:
                 return b''
 
         def find_cookie(line):
             try:
                 line_string = line.decode('ascii')
             except UnicodeDecodeError:
                 return None
 
             matches = cookie_re.findall(line_string)
             if not matches:
                 return None
             encoding = _get_normal_name(matches[0])
             try:
                 codec = lookup(encoding)
             except LookupError:
                 # This behaviour mimics the Python interpreter
                 raise SyntaxError("unknown encoding: " + encoding)
 
             if bom_found:
                 if codec.name != 'utf-8':
                     # This behaviour mimics the Python interpreter
                     raise SyntaxError('encoding problem: utf-8')
                 encoding += '-sig'
             return encoding
 
         first = read_or_stop()
         if first.startswith(BOM_UTF8):
             bom_found = True
             first = first[3:]
             default = 'utf-8-sig'
         if not first:
             return default, []
 
         encoding = find_cookie(first)
         if encoding:
             return encoding, [first]
 
         second = read_or_stop()
         if not second:
             return default, [first]
 
         encoding = find_cookie(second)
         if encoding:
             return encoding, [first, second]
 
         return default, [first, second]
 
 try:
     # Available in Python 3.2 and above.
     from tokenize import open
 except ImportError:
     # Copied from Python 3.2 tokenize
     def open(filename):
         """Open a file in read only mode using the encoding detected by
         detect_encoding().
         """
         buffer = io.open(filename, 'rb')   # Tweaked to use io.open for Python 2
         encoding, lines = detect_encoding(buffer.readline)
         buffer.seek(0)
         text = TextIOWrapper(buffer, encoding, line_buffering=True)
         text.mode = 'r'
         return text   
 
 def source_to_unicode(txt, errors='replace', skip_encoding_cookie=True):
     """Converts a bytes string with python source code to unicode.
 
     Unicode strings are passed through unchanged. Byte strings are checked
     for the python source file encoding cookie to determine encoding.
     txt can be either a bytes buffer or a string containing the source
     code.
     """
     if isinstance(txt, unicode):
         return txt
     if isinstance(txt, bytes):
         buffer = BytesIO(txt)
     else:
         buffer = txt
     try:
         encoding, _ = detect_encoding(buffer.readline)
     except SyntaxError:
         encoding = "ascii"
     buffer.seek(0)
     text = TextIOWrapper(buffer, encoding, errors=errors, line_buffering=True)
     text.mode = 'r'
     if skip_encoding_cookie:
         return u"".join(strip_encoding_cookie(text))
     else:
         return text.read()
 
 def strip_encoding_cookie(filelike):
     """Generator to pull lines from a text-mode file, skipping the encoding
     cookie if it is found in the first two lines.
     """
     it = iter(filelike)
     try:
         first = next(it)
         if not cookie_comment_re.match(first):
             yield first
         second = next(it)
         if not cookie_comment_re.match(second):
             yield second
     except StopIteration:
         return
     
     for line in it:
         yield line
 
 def read_py_file(filename, skip_encoding_cookie=True):
     """Read a Python file, using the encoding declared inside the file.
     
     Parameters
     ----------
     filename : str
       The path to the file to read.
     skip_encoding_cookie : bool
       If True (the default), and the encoding declaration is found in the first
       two lines, that line will be excluded from the output - compiling a
       unicode string with an encoding declaration is a SyntaxError in Python 2.
     
     Returns
     -------
     A unicode string containing the contents of the file.
     """
     with open(filename) as f:   # the open function defined in this module.
         if skip_encoding_cookie:
             return "".join(strip_encoding_cookie(f))
         else:
             return f.read()
 
 def read_py_url(url, errors='replace', skip_encoding_cookie=True):
     """Read a Python file from a URL, using the encoding declared inside the file.
     
     Parameters
     ----------
     url : str
       The URL from which to fetch the file.
     errors : str
       How to handle decoding errors in the file. Options are the same as for
       bytes.decode(), but here 'replace' is the default.
     skip_encoding_cookie : bool
       If True (the default), and the encoding declaration is found in the first
       two lines, that line will be excluded from the output - compiling a
       unicode string with an encoding declaration is a SyntaxError in Python 2.
     
     Returns
     -------
     A unicode string containing the contents of the file.
     """
     from urllib import urlopen  # Deferred import for faster start
     response = urlopen(url)
     buffer = io.BytesIO(response.read())
     return source_to_unicode(buffer, errors, skip_encoding_cookie)
 
 def _list_readline(x):
     """Given a list, returns a readline() function that returns the next element
     with each call.
     """
     x = iter(x)
     def readline():
         return next(x)
     return readline
+
+# Code for going between .py files and cached .pyc files ----------------------
+
+try:    # Python 3.2, see PEP 3147
+    from imp import source_from_cache, cache_from_source
+except ImportError:
+    # Python <= 3.1: .pyc files go next to .py
+    def source_from_cache(path):
+        basename, ext = os.path.splitext(path)
+        if ext not in ('.pyc', '.pyo'):
+            raise ValueError('Not a cached Python file extension', ext)
+        # Should we look for .pyw files?
+        return basename + '.py'
+    
+    def cache_from_source(path, debug_override=None):
+        if debug_override is None:
+            debug_override = __debug__
+        basename, ext = os.path.splitext(path)
+        return basename + '.pyc' if debug_override else '.pyo'

IPython/utils/text.py

@@ -1,824 +1,717
 # encoding: utf-8
 """
 Utilities for working with strings and text.
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.utils.text
    :parts: 3
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import __main__
 
 import os
 import re
 import sys
 import textwrap
 from string import Formatter
 
 from IPython.external.path import path
 from IPython.testing.skipdoctest import skip_doctest_py3, skip_doctest
 from IPython.utils import py3compat
-from IPython.utils.io import nlprint
 from IPython.utils.data import flatten
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
-def unquote_ends(istr):
-    """Remove a single pair of quotes from the endpoints of a string."""
-
-    if not istr:
-        return istr
-    if (istr[0]=="'" and istr[-1]=="'") or \
-       (istr[0]=='"' and istr[-1]=='"'):
-        return istr[1:-1]
-    else:
-        return istr
-
-
 class LSString(str):
     """String derivative with a special access attributes.
 
     These are normal strings, but with the special attributes:
 
         .l (or .list) : value as list (split on newlines).
         .n (or .nlstr): original value (the string itself).
         .s (or .spstr): value as whitespace-separated string.
         .p (or .paths): list of path objects
 
     Any values which require transformations are computed only once and
     cached.
 
     Such strings are very useful to efficiently interact with the shell, which
     typically only understands whitespace-separated options for commands."""
 
     def get_list(self):
         try:
             return self.__list
         except AttributeError:
             self.__list = self.split('\n')
             return self.__list
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = self.replace('\n',' ')
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         return self
 
     n = nlstr = property(get_nlstr)
 
     def get_paths(self):
         try:
             return self.__paths
         except AttributeError:
             self.__paths = [path(p) for p in self.split('\n') if os.path.exists(p)]
             return self.__paths
 
     p = paths = property(get_paths)
 
 # FIXME: We need to reimplement type specific displayhook and then add this
 # back as a custom printer. This should also be moved outside utils into the
 # core.
 
 # def print_lsstring(arg):
 #     """ Prettier (non-repr-like) and more informative printer for LSString """
 #     print "LSString (.p, .n, .l, .s available). Value:"
 #     print arg
 #
 #
 # print_lsstring = result_display.when_type(LSString)(print_lsstring)
 
 
 class SList(list):
     """List derivative with a special access attributes.
 
     These are normal lists, but with the special attributes:
 
         .l (or .list) : value as list (the list itself).
         .n (or .nlstr): value as a string, joined on newlines.
         .s (or .spstr): value as a string, joined on spaces.
         .p (or .paths): list of path objects
 
     Any values which require transformations are computed only once and
     cached."""
 
     def get_list(self):
         return self
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = ' '.join(self)
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         try:
             return self.__nlstr
         except AttributeError:
             self.__nlstr = '\n'.join(self)
             return self.__nlstr
 
     n = nlstr = property(get_nlstr)
 
     def get_paths(self):
         try:
             return self.__paths
         except AttributeError:
             self.__paths = [path(p) for p in self if os.path.exists(p)]
             return self.__paths
 
     p = paths = property(get_paths)
 
     def grep(self, pattern, prune = False, field = None):
         """ Return all strings matching 'pattern' (a regex or callable)
 
         This is case-insensitive. If prune is true, return all items
         NOT matching the pattern.
 
         If field is specified, the match must occur in the specified
         whitespace-separated field.
 
         Examples::
 
             a.grep( lambda x: x.startswith('C') )
             a.grep('Cha.*log', prune=1)
             a.grep('chm', field=-1)
         """
 
         def match_target(s):
             if field is None:
                 return s
             parts = s.split()
             try:
                 tgt = parts[field]
                 return tgt
             except IndexError:
                 return ""
 
         if isinstance(pattern, basestring):
             pred = lambda x : re.search(pattern, x, re.IGNORECASE)
         else:
             pred = pattern
         if not prune:
             return SList([el for el in self if pred(match_target(el))])
         else:
             return SList([el for el in self if not pred(match_target(el))])
 
     def fields(self, *fields):
         """ Collect whitespace-separated fields from string list
 
         Allows quick awk-like usage of string lists.
 
         Example data (in var a, created by 'a = !ls -l')::
             -rwxrwxrwx  1 ville None      18 Dec 14  2006 ChangeLog
             drwxrwxrwx+ 6 ville None       0 Oct 24 18:05 IPython
 
         a.fields(0) is ['-rwxrwxrwx', 'drwxrwxrwx+']
         a.fields(1,0) is ['1 -rwxrwxrwx', '6 drwxrwxrwx+']
         (note the joining by space).
         a.fields(-1) is ['ChangeLog', 'IPython']
 
         IndexErrors are ignored.
 
         Without args, fields() just split()'s the strings.
         """
         if len(fields) == 0:
             return [el.split() for el in self]
 
         res = SList()
         for el in [f.split() for f in self]:
             lineparts = []
 
             for fd in fields:
                 try:
                     lineparts.append(el[fd])
                 except IndexError:
                     pass
             if lineparts:
                 res.append(" ".join(lineparts))
 
         return res
 
     def sort(self,field= None,  nums = False):
         """ sort by specified fields (see fields())
 
         Example::
             a.sort(1, nums = True)
 
         Sorts a by second field, in numerical order (so that 21 > 3)
 
         """
 
         #decorate, sort, undecorate
         if field is not None:
             dsu = [[SList([line]).fields(field),  line] for line in self]
         else:
             dsu = [[line,  line] for line in self]
         if nums:
             for i in range(len(dsu)):
                 numstr = "".join([ch for ch in dsu[i][0] if ch.isdigit()])
                 try:
                     n = int(numstr)
                 except ValueError:
                     n = 0;
                 dsu[i][0] = n
 
 
         dsu.sort()
         return SList([t[1] for t in dsu])
 
 
 # FIXME: We need to reimplement type specific displayhook and then add this
 # back as a custom printer. This should also be moved outside utils into the
 # core.
 
 # def print_slist(arg):
 #     """ Prettier (non-repr-like) and more informative printer for SList """
 #     print "SList (.p, .n, .l, .s, .grep(), .fields(), sort() available):"
 #     if hasattr(arg,  'hideonce') and arg.hideonce:
 #         arg.hideonce = False
 #         return
 #
-#     nlprint(arg)
+#     nlprint(arg)   # This was a nested list printer, now removed.
 #
 # print_slist = result_display.when_type(SList)(print_slist)
 
 
-def esc_quotes(strng):
-    """Return the input string with single and double quotes escaped out"""
-
-    return strng.replace('"','\\"').replace("'","\\'")
-
-
-def qw(words,flat=0,sep=None,maxsplit=-1):
-    """Similar to Perl's qw() operator, but with some more options.
-
-    qw(words,flat=0,sep=' ',maxsplit=-1) -> words.split(sep,maxsplit)
-
-    words can also be a list itself, and with flat=1, the output will be
-    recursively flattened.
-
-    Examples:
-
-    >>> qw('1 2')
-    ['1', '2']
-
-    >>> qw(['a b','1 2',['m n','p q']])
-    [['a', 'b'], ['1', '2'], [['m', 'n'], ['p', 'q']]]
-
-    >>> qw(['a b','1 2',['m n','p q']],flat=1)
-    ['a', 'b', '1', '2', 'm', 'n', 'p', 'q']
-    """
-
-    if isinstance(words, basestring):
-        return [word.strip() for word in words.split(sep,maxsplit)
-                if word and not word.isspace() ]
-    if flat:
-        return flatten(map(qw,words,[1]*len(words)))
-    return map(qw,words)
-
-
-def qwflat(words,sep=None,maxsplit=-1):
-    """Calls qw(words) in flat mode. It's just a convenient shorthand."""
-    return qw(words,1,sep,maxsplit)
-
-
-def qw_lol(indata):
-    """qw_lol('a b') -> [['a','b']],
-    otherwise it's just a call to qw().
-
-    We need this to make sure the modules_some keys *always* end up as a
-    list of lists."""
-
-    if isinstance(indata, basestring):
-        return [qw(indata)]
-    else:
-        return qw(indata)
-
-
-def grep(pat,list,case=1):
-    """Simple minded grep-like function.
-    grep(pat,list) returns occurrences of pat in list, None on failure.
-
-    It only does simple string matching, with no support for regexps. Use the
-    option case=0 for case-insensitive matching."""
-
-    # This is pretty crude. At least it should implement copying only references
-    # to the original data in case it's big. Now it copies the data for output.
-    out=[]
-    if case:
-        for term in list:
-            if term.find(pat)>-1: out.append(term)
-    else:
-        lpat=pat.lower()
-        for term in list:
-            if term.lower().find(lpat)>-1: out.append(term)
-
-    if len(out): return out
-    else: return None
-
-
-def dgrep(pat,*opts):
-    """Return grep() on dir()+dir(__builtins__).
-
-    A very common use of grep() when working interactively."""
-
-    return grep(pat,dir(__main__)+dir(__main__.__builtins__),*opts)
-
-
-def idgrep(pat):
-    """Case-insensitive dgrep()"""
-
-    return dgrep(pat,0)
-
-
-def igrep(pat,list):
-    """Synonym for case-insensitive grep."""
-
-    return grep(pat,list,case=0)
-
-
 def indent(instr,nspaces=4, ntabs=0, flatten=False):
     """Indent a string a given number of spaces or tabstops.
 
     indent(str,nspaces=4,ntabs=0) -> indent str by ntabs+nspaces.
 
     Parameters
     ----------
 
     instr : basestring
         The string to be indented.
     nspaces : int (default: 4)
         The number of spaces to be indented.
     ntabs : int (default: 0)
         The number of tabs to be indented.
     flatten : bool (default: False)
         Whether to scrub existing indentation.  If True, all lines will be
         aligned to the same indentation.  If False, existing indentation will
         be strictly increased.
 
     Returns
     -------
 
     str|unicode : string indented by ntabs and nspaces.
 
     """
     if instr is None:
         return
     ind = '\t'*ntabs+' '*nspaces
     if flatten:
         pat = re.compile(r'^\s*', re.MULTILINE)
     else:
         pat = re.compile(r'^', re.MULTILINE)
     outstr = re.sub(pat, ind, instr)
     if outstr.endswith(os.linesep+ind):
         return outstr[:-len(ind)]
     else:
         return outstr
 
 
 def list_strings(arg):
     """Always return a list of strings, given a string or list of strings
     as input.
 
     :Examples:
 
         In [7]: list_strings('A single string')
         Out[7]: ['A single string']
 
         In [8]: list_strings(['A single string in a list'])
         Out[8]: ['A single string in a list']
 
         In [9]: list_strings(['A','list','of','strings'])
         Out[9]: ['A', 'list', 'of', 'strings']
     """
 
     if isinstance(arg,basestring): return [arg]
     else: return arg
 
 
 def marquee(txt='',width=78,mark='*'):
     """Return the input string centered in a 'marquee'.
 
     :Examples:
 
         In [16]: marquee('A test',40)
         Out[16]: '**************** A test ****************'
 
         In [17]: marquee('A test',40,'-')
         Out[17]: '---------------- A test ----------------'
 
         In [18]: marquee('A test',40,' ')
         Out[18]: '                 A test                 '
 
     """
     if not txt:
         return (mark*width)[:width]
     nmark = (width-len(txt)-2)//len(mark)//2
     if nmark < 0: nmark =0
     marks = mark*nmark
     return '%s %s %s' % (marks,txt,marks)
 
 
 ini_spaces_re = re.compile(r'^(\s+)')
 
 def num_ini_spaces(strng):
     """Return the number of initial spaces in a string"""
 
     ini_spaces = ini_spaces_re.match(strng)
     if ini_spaces:
         return ini_spaces.end()
     else:
         return 0
 
 
 def format_screen(strng):
     """Format a string for screen printing.
 
     This removes some latex-type format codes."""
     # Paragraph continue
     par_re = re.compile(r'\\$',re.MULTILINE)
     strng = par_re.sub('',strng)
     return strng
 
 
 def dedent(text):
     """Equivalent of textwrap.dedent that ignores unindented first line.
 
     This means it will still dedent strings like:
     '''foo
     is a bar
     '''
 
     For use in wrap_paragraphs.
     """
 
     if text.startswith('\n'):
         # text starts with blank line, don't ignore the first line
         return textwrap.dedent(text)
 
     # split first line
     splits = text.split('\n',1)
     if len(splits) == 1:
         # only one line
         return textwrap.dedent(text)
 
     first, rest = splits
     # dedent everything but the first line
     rest = textwrap.dedent(rest)
     return '\n'.join([first, rest])
 
 
 def wrap_paragraphs(text, ncols=80):
     """Wrap multiple paragraphs to fit a specified width.
 
     This is equivalent to textwrap.wrap, but with support for multiple
     paragraphs, as separated by empty lines.
 
     Returns
     -------
 
     list of complete paragraphs, wrapped to fill `ncols` columns.
     """
     paragraph_re = re.compile(r'\n(\s*\n)+', re.MULTILINE)
     text = dedent(text).strip()
     paragraphs = paragraph_re.split(text)[::2] # every other entry is space
     out_ps = []
     indent_re = re.compile(r'\n\s+', re.MULTILINE)
     for p in paragraphs:
         # presume indentation that survives dedent is meaningful formatting,
         # so don't fill unless text is flush.
         if indent_re.search(p) is None:
             # wrap paragraph
             p = textwrap.fill(p, ncols)
         out_ps.append(p)
     return out_ps
 
 
 def long_substr(data):
     """Return the longest common substring in a list of strings.
     
     Credit: http://stackoverflow.com/questions/2892931/longest-common-substring-from-more-than-two-strings-python
     """
     substr = ''
     if len(data) > 1 and len(data[0]) > 0:
         for i in range(len(data[0])):
             for j in range(len(data[0])-i+1):
                 if j > len(substr) and all(data[0][i:i+j] in x for x in data):
                     substr = data[0][i:i+j]
     elif len(data) == 1:
         substr = data[0]
     return substr
 
 
 def strip_email_quotes(text):
     """Strip leading email quotation characters ('>').
 
     Removes any combination of leading '>' interspersed with whitespace that
     appears *identically* in all lines of the input text.
 
     Parameters
     ----------
     text : str
 
     Examples
     --------
 
     Simple uses::
 
         In [2]: strip_email_quotes('> > text')
         Out[2]: 'text'
 
         In [3]: strip_email_quotes('> > text\\n> > more')
         Out[3]: 'text\\nmore'
 
     Note how only the common prefix that appears in all lines is stripped::
 
         In [4]: strip_email_quotes('> > text\\n> > more\\n> more...')
         Out[4]: '> text\\n> more\\nmore...'
 
     So if any line has no quote marks ('>') , then none are stripped from any
     of them ::
     
         In [5]: strip_email_quotes('> > text\\n> > more\\nlast different')
         Out[5]: '> > text\\n> > more\\nlast different'
     """
     lines = text.splitlines()
     matches = set()
     for line in lines:
         prefix = re.match(r'^(\s*>[ >]*)', line)
         if prefix:
             matches.add(prefix.group(1))
         else:
             break
     else:
         prefix = long_substr(list(matches))
         if prefix:
             strip = len(prefix)
             text = '\n'.join([ ln[strip:] for ln in lines])
     return text
 
 
 class EvalFormatter(Formatter):
     """A String Formatter that allows evaluation of simple expressions.
     
     Note that this version interprets a : as specifying a format string (as per
     standard string formatting), so if slicing is required, you must explicitly
     create a slice.
     
     This is to be used in templating cases, such as the parallel batch
     script templates, where simple arithmetic on arguments is useful.
 
     Examples
     --------
     
     In  [1]: f = EvalFormatter()
     In  [2]: f.format('{n//4}', n=8)
     Out [2]: '2'
     
     In  [3]: f.format("{greeting[slice(2,4)]}", greeting="Hello")
     Out [3]: 'll'
     """
     def get_field(self, name, args, kwargs):
         v = eval(name, kwargs)
         return v, name
 
 
 @skip_doctest_py3
 class FullEvalFormatter(Formatter):
     """A String Formatter that allows evaluation of simple expressions.
     
     Any time a format key is not found in the kwargs,
     it will be tried as an expression in the kwargs namespace.
     
     Note that this version allows slicing using [1:2], so you cannot specify
     a format string. Use :class:`EvalFormatter` to permit format strings.
     
     Examples
     --------
     
     In [1]: f = FullEvalFormatter()
     In [2]: f.format('{n//4}', n=8)
     Out[2]: u'2'
     
     In [3]: f.format('{list(range(5))[2:4]}')
     Out[3]: u'[2, 3]'
 
     In [4]: f.format('{3*2}')
     Out[4]: u'6'
     """
     # copied from Formatter._vformat with minor changes to allow eval
     # and replace the format_spec code with slicing
     def _vformat(self, format_string, args, kwargs, used_args, recursion_depth):
         if recursion_depth < 0:
             raise ValueError('Max string recursion exceeded')
         result = []
         for literal_text, field_name, format_spec, conversion in \
                 self.parse(format_string):
 
             # output the literal text
             if literal_text:
                 result.append(literal_text)
 
             # if there's a field, output it
             if field_name is not None:
                 # this is some markup, find the object and do
                 # the formatting
 
                 if format_spec:
                     # override format spec, to allow slicing:
                     field_name = ':'.join([field_name, format_spec])
 
                 # eval the contents of the field for the object
                 # to be formatted
                 obj = eval(field_name, kwargs)
 
                 # do any conversion on the resulting object
                 obj = self.convert_field(obj, conversion)
 
                 # format the object and append to the result
                 result.append(self.format_field(obj, ''))
 
         return u''.join(py3compat.cast_unicode(s) for s in result)
 
 
 @skip_doctest_py3
 class DollarFormatter(FullEvalFormatter):
     """Formatter allowing Itpl style $foo replacement, for names and attribute
     access only. Standard {foo} replacement also works, and allows full
     evaluation of its arguments.
 
     Examples
     --------
     In [1]: f = DollarFormatter()
     In [2]: f.format('{n//4}', n=8)
     Out[2]: u'2'
     
     In [3]: f.format('23 * 76 is $result', result=23*76)
     Out[3]: u'23 * 76 is 1748'
     
     In [4]: f.format('$a or {b}', a=1, b=2)
     Out[4]: u'1 or 2'
     """
     _dollar_pattern = re.compile("(.*?)\$(\$?[\w\.]+)")
     def parse(self, fmt_string):
         for literal_txt, field_name, format_spec, conversion \
                     in Formatter.parse(self, fmt_string):
             
             # Find $foo patterns in the literal text.
             continue_from = 0
             txt = ""
             for m in self._dollar_pattern.finditer(literal_txt):
                 new_txt, new_field = m.group(1,2)
                 # $$foo --> $foo
                 if new_field.startswith("$"):
                     txt += new_txt + new_field
                 else:
                     yield (txt + new_txt, new_field, "", None)
                     txt = ""
                 continue_from = m.end()
             
             # Re-yield the {foo} style pattern
             yield (txt + literal_txt[continue_from:], field_name, format_spec, conversion)
 
 #-----------------------------------------------------------------------------
 # Utils to columnize a list of string
 #-----------------------------------------------------------------------------
 
 def _chunks(l, n):
     """Yield successive n-sized chunks from l."""
     for i in xrange(0, len(l), n):
         yield l[i:i+n]
 
 
 def _find_optimal(rlist , separator_size=2 , displaywidth=80):
     """Calculate optimal info to columnize a list of string"""
     for nrow in range(1, len(rlist)+1) :
         chk = map(max,_chunks(rlist, nrow))
         sumlength = sum(chk)
         ncols = len(chk)
         if sumlength+separator_size*(ncols-1) <= displaywidth :
             break;
     return {'columns_numbers' : ncols,
             'optimal_separator_width':(displaywidth - sumlength)/(ncols-1) if (ncols -1) else 0,
             'rows_numbers' : nrow,
             'columns_width' : chk
            }
 
 
 def _get_or_default(mylist, i, default=None):
     """return list item number, or default if don't exist"""
     if i >= len(mylist):
         return default
     else :
         return mylist[i]
 
 
 @skip_doctest
 def compute_item_matrix(items, empty=None, *args, **kwargs) :
     """Returns a nested list, and info to columnize items
 
     Parameters
     ----------
 
     items :
         list of strings to columize
     empty : (default None)
         default value to fill list if needed
     separator_size : int (default=2)
         How much caracters will be used as a separation between each columns.
     displaywidth : int (default=80)
         The width of the area onto wich the columns should enter
 
     Returns
     -------
 
     Returns a tuple of (strings_matrix, dict_info)
 
     strings_matrix :
 
         nested list of string, the outer most list contains as many list as
         rows, the innermost lists have each as many element as colums. If the
         total number of elements in `items` does not equal the product of
         rows*columns, the last element of some lists are filled with `None`.
 
     dict_info :
         some info to make columnize easier:
 
         columns_numbers : number of columns
         rows_numbers    : number of rows
         columns_width   : list of with of each columns
         optimal_separator_width : best separator width between columns
 
     Examples
     --------
 
     In [1]: l = ['aaa','b','cc','d','eeeee','f','g','h','i','j','k','l']
        ...: compute_item_matrix(l,displaywidth=12)
     Out[1]:
         ([['aaa', 'f', 'k'],
         ['b', 'g', 'l'],
         ['cc', 'h', None],
         ['d', 'i', None],
         ['eeeee', 'j', None]],
         {'columns_numbers': 3,
         'columns_width': [5, 1, 1],
         'optimal_separator_width': 2,
         'rows_numbers': 5})
 
     """
     info = _find_optimal(map(len, items), *args, **kwargs)
     nrow, ncol = info['rows_numbers'], info['columns_numbers']
     return ([[ _get_or_default(items, c*nrow+i, default=empty) for c in range(ncol) ] for i in range(nrow) ], info)
 
 
 def columnize(items, separator='  ', displaywidth=80):
     """ Transform a list of strings into a single string with columns.
 
     Parameters
     ----------
     items : sequence of strings
         The strings to process.
 
     separator : str, optional [default is two spaces]
         The string that separates columns.
 
     displaywidth : int, optional [default is 80]
         Width of the display in number of characters.
 
     Returns
     -------
     The formatted string.
     """
     if not items :
         return '\n'
     matrix, info = compute_item_matrix(items, separator_size=len(separator), displaywidth=displaywidth)
     fmatrix = [filter(None, x) for x in matrix]
     sjoin = lambda x : separator.join([ y.ljust(w, ' ') for y, w in zip(x, info['columns_width'])])
     return '\n'.join(map(sjoin, fmatrix))+'\n'