Ensure that __file__ is defined when loading scripts.

Minor formatting cleanup (lines > 80 chars)

Closes https://bugs.launchpad.net/ipython/+bug/400818

IPython/core/ipapp.py

@@ -1,653 +1,665 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 The :class:`~IPython.core.application.Application` object for the command
 line :command:`ipython` program.
 
 Authors
 -------
 
 * Brian Granger
 * Fernando Perez
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2010  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 from __future__ import absolute_import
 
 import logging
 import os
 import sys
 
 from IPython.core import release
 from IPython.core.crashhandler import CrashHandler
 from IPython.core.application import Application, BaseAppConfigLoader
 from IPython.core.iplib import InteractiveShell
 from IPython.config.loader import (
     Config,
     PyFileConfigLoader
 )
 from IPython.lib import inputhook
 from IPython.utils.path import filefind, get_ipython_dir
 from . import usage
 
 #-----------------------------------------------------------------------------
 # Globals, utilities and helpers
 #-----------------------------------------------------------------------------
 
 #: The default config file name for this application.
 default_config_file_name = u'ipython_config.py'
 
 
 class IPAppConfigLoader(BaseAppConfigLoader):
 
     def _add_arguments(self):
         super(IPAppConfigLoader, self)._add_arguments()
         paa = self.parser.add_argument
         paa('-p', 
             '--profile', dest='Global.profile', type=unicode,
             help=
             """The string name of the ipython profile to be used.  Assume that your
             config file is ipython_config-<name>.py (looks in current dir first,
             then in IPYTHON_DIR). This is a quick way to keep and load multiple
             config files for different tasks, especially if include your basic one
             in your more specialized ones.  You can keep a basic
             IPYTHON_DIR/ipython_config.py file and then have other 'profiles' which
             include this one and load extra things for particular tasks.""",
             metavar='Global.profile')
         paa('--config-file', 
             dest='Global.config_file', type=unicode,
             help=
             """Set the config file name to override default.  Normally IPython
             loads ipython_config.py (from current directory) or
             IPYTHON_DIR/ipython_config.py.  If the loading of your config file
             fails, IPython starts with a bare bones configuration (no modules
             loaded at all).""",
             metavar='Global.config_file')
         paa('--autocall', 
             dest='InteractiveShell.autocall', type=int, 
             help=
             """Make IPython automatically call any callable object even if you
             didn't type explicit parentheses. For example, 'str 43' becomes
             'str(43)' automatically.  The value can be '0' to disable the feature,
             '1' for 'smart' autocall, where it is not applied if there are no more
             arguments on the line, and '2' for 'full' autocall, where all callable
             objects are automatically called (even if no arguments are present).
             The default is '1'.""",
             metavar='InteractiveShell.autocall')
         paa('--autoindent',
             action='store_true', dest='InteractiveShell.autoindent',
             help='Turn on autoindenting.')
         paa('--no-autoindent',
             action='store_false', dest='InteractiveShell.autoindent',
             help='Turn off autoindenting.')
         paa('--automagic',
             action='store_true', dest='InteractiveShell.automagic',
             help=
             """Turn on the auto calling of magic commands. Type %%magic at the
             IPython  prompt  for  more information.""")
         paa('--no-automagic',
             action='store_false', dest='InteractiveShell.automagic',
             help='Turn off the auto calling of magic commands.')
         paa('--autoedit-syntax',
             action='store_true', dest='InteractiveShell.autoedit_syntax',
             help='Turn on auto editing of files with syntax errors.')
         paa('--no-autoedit-syntax',
             action='store_false', dest='InteractiveShell.autoedit_syntax',
             help='Turn off auto editing of files with syntax errors.')
         paa('--banner',
             action='store_true', dest='Global.display_banner',
             help='Display a banner upon starting IPython.')
         paa('--no-banner',
             action='store_false', dest='Global.display_banner',
             help="Don't display a banner upon starting IPython.")
         paa('--cache-size',
             type=int, dest='InteractiveShell.cache_size',
             help=
             """Set the size of the output cache.  The default is 1000, you can
             change it permanently in your config file.  Setting it to 0 completely
             disables the caching system, and the minimum value accepted is 20 (if
             you provide a value less than 20, it is reset to 0 and a warning is
             issued).  This limit is defined because otherwise you'll spend more
             time re-flushing a too small cache than working""",
             metavar='InteractiveShell.cache_size')
         paa('--classic',
             action='store_true', dest='Global.classic',
             help="Gives IPython a similar feel to the classic Python prompt.")
         paa('--colors',
             type=str, dest='InteractiveShell.colors',
             help="Set the color scheme (NoColor, Linux, and LightBG).",
             metavar='InteractiveShell.colors')
         paa('--color-info',
             action='store_true', dest='InteractiveShell.color_info',
             help=
             """IPython can display information about objects via a set of func-
             tions, and optionally can use colors for this, syntax highlighting
             source code and various other elements.  However, because this
             information is passed through a pager (like 'less') and many pagers get
             confused with color codes, this option is off by default.  You can test
             it and turn it on permanently in your ipython_config.py file if it
             works for you.  Test it and turn it on permanently if it works with
             your system.  The magic function %%color_info allows you to toggle this
             inter- actively for testing.""")
         paa('--no-color-info',
             action='store_false', dest='InteractiveShell.color_info',
             help="Disable using colors for info related things.")
         paa('--confirm-exit',
             action='store_true', dest='InteractiveShell.confirm_exit',
             help=
             """Set to confirm when you try to exit IPython with an EOF (Control-D
             in Unix, Control-Z/Enter in Windows). By typing 'exit', 'quit' or
             '%%Exit', you can force a direct exit without any confirmation.""")
         paa('--no-confirm-exit',
             action='store_false', dest='InteractiveShell.confirm_exit',
             help="Don't prompt the user when exiting.")
         paa('--deep-reload',
             action='store_true', dest='InteractiveShell.deep_reload',
             help=
             """Enable deep (recursive) reloading by default. IPython can use the
             deep_reload module which reloads changes in modules recursively (it
             replaces the reload() function, so you don't need to change anything to
             use it). deep_reload() forces a full reload of modules whose code may
             have changed, which the default reload() function does not.  When
             deep_reload is off, IPython will use the normal reload(), but
             deep_reload will still be available as dreload(). This fea- ture is off
             by default [which means that you have both normal reload() and
             dreload()].""")
         paa('--no-deep-reload',
             action='store_false', dest='InteractiveShell.deep_reload',
             help="Disable deep (recursive) reloading by default.")
         paa('--editor',
             type=str, dest='InteractiveShell.editor',
             help="Set the editor used by IPython (default to $EDITOR/vi/notepad).",
             metavar='InteractiveShell.editor')
         paa('--log','-l', 
             action='store_true', dest='InteractiveShell.logstart',
             help="Start logging to the default log file (./ipython_log.py).")
         paa('--logfile','-lf',
             type=unicode, dest='InteractiveShell.logfile',
             help="Start logging to logfile with this name.",
             metavar='InteractiveShell.logfile')
         paa('--log-append','-la',
             type=unicode, dest='InteractiveShell.logappend',
             help="Start logging to the given file in append mode.",
             metavar='InteractiveShell.logfile')
         paa('--pdb',
             action='store_true', dest='InteractiveShell.pdb',
             help="Enable auto calling the pdb debugger after every exception.")
         paa('--no-pdb',
             action='store_false', dest='InteractiveShell.pdb',
             help="Disable auto calling the pdb debugger after every exception.")
         paa('--pprint',
             action='store_true', dest='InteractiveShell.pprint',
             help="Enable auto pretty printing of results.")
         paa('--no-pprint',
             action='store_false', dest='InteractiveShell.pprint',
             help="Disable auto auto pretty printing of results.")
         paa('--prompt-in1','-pi1',
             type=str, dest='InteractiveShell.prompt_in1',
             help=
             """Set the main input prompt ('In [\#]: ').  Note that if you are using
             numbered prompts, the number is represented with a '\#' in the string.
             Don't forget to quote strings with spaces embedded in them. Most
             bash-like escapes can be used to customize IPython's prompts, as well
             as a few additional ones which are IPython-spe- cific.  All valid
             prompt escapes are described in detail in the Customization section of
             the IPython manual.""",
             metavar='InteractiveShell.prompt_in1')
         paa('--prompt-in2','-pi2',
             type=str, dest='InteractiveShell.prompt_in2',
             help=
             """Set the secondary input prompt (' .\D.: ').  Similar to the previous
             option, but used for the continuation prompts. The special sequence
             '\D' is similar to '\#', but with all digits replaced by dots (so you
             can have your continuation prompt aligned with your input prompt).
             Default: ' .\D.: ' (note three spaces at the start for alignment with
             'In [\#]')""",
             metavar='InteractiveShell.prompt_in2')
         paa('--prompt-out','-po',
             type=str, dest='InteractiveShell.prompt_out',
             help="Set the output prompt ('Out[\#]:')",
             metavar='InteractiveShell.prompt_out')
         paa('--quick',
             action='store_true', dest='Global.quick',
             help="Enable quick startup with no config files.")
         paa('--readline',
             action='store_true', dest='InteractiveShell.readline_use',
             help="Enable readline for command line usage.")
         paa('--no-readline',
             action='store_false', dest='InteractiveShell.readline_use',
             help="Disable readline for command line usage.")
         paa('--screen-length','-sl',
             type=int, dest='InteractiveShell.screen_length',
             help=
             """Number of lines of your screen, used to control printing of very
             long strings.  Strings longer than this number of lines will be sent
             through a pager instead of directly printed.  The default value for
             this is 0, which means IPython will auto-detect your screen size every
             time it needs to print certain potentially long strings (this doesn't
             change the behavior of the 'print' keyword, it's only triggered
             internally). If for some reason this isn't working well (it needs
             curses support), specify it yourself. Otherwise don't change the
             default.""",
             metavar='InteractiveShell.screen_length')
         paa('--separate-in','-si',
             type=str, dest='InteractiveShell.separate_in',
             help="Separator before input prompts.  Default '\\n'.",
             metavar='InteractiveShell.separate_in')
         paa('--separate-out','-so',
             type=str, dest='InteractiveShell.separate_out',
             help="Separator before output prompts.  Default 0 (nothing).",
             metavar='InteractiveShell.separate_out')
         paa('--separate-out2','-so2', 
             type=str, dest='InteractiveShell.separate_out2',
             help="Separator after output prompts.  Default 0 (nonight).",
             metavar='InteractiveShell.separate_out2')
         paa('--no-sep',
             action='store_true', dest='Global.nosep',
             help="Eliminate all spacing between prompts.")
         paa('--term-title',
             action='store_true', dest='InteractiveShell.term_title',
             help="Enable auto setting the terminal title.")
         paa('--no-term-title',
             action='store_false', dest='InteractiveShell.term_title',
             help="Disable auto setting the terminal title.")
         paa('--xmode',
             type=str, dest='InteractiveShell.xmode',
             help=
             """Exception reporting mode ('Plain','Context','Verbose').  Plain:
             similar to python's normal traceback printing.  Context: prints 5 lines
             of context source code around each line in the traceback.  Verbose:
             similar to Context, but additionally 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).
             """,
             metavar='InteractiveShell.xmode')
         paa('--ext',
             type=str, dest='Global.extra_extension',
             help="The dotted module name of an IPython extension to load.",
             metavar='Global.extra_extension')
         paa('-c',
             type=str, dest='Global.code_to_run',
             help="Execute the given command string.",
             metavar='Global.code_to_run')
         paa('-i',
             action='store_true', dest='Global.force_interact',
             help=
             "If running code from the command line, become interactive afterwards.")
 
         # Options to start with GUI control enabled from the beginning
         paa('--gui',
             type=str, dest='Global.gui',
             help="Enable GUI event loop integration ('qt', 'wx', 'gtk').",
             metavar='gui-mode')
         paa('--pylab','-pylab',
             type=str, dest='Global.pylab',
             nargs='?', const='auto', metavar='gui-mode',
             help="Pre-load matplotlib and numpy for interactive use. "+
             "If no value is given, the gui backend is matplotlib's, else use "+
             "one of:  ['tk', 'qt', 'wx', 'gtk'].")
 
         # Legacy GUI options.  Leave them in for backwards compatibility, but the
         # 'thread' names are really a misnomer now.
         paa('--wthread', '-wthread',
             action='store_true', dest='Global.wthread',
             help=
             """Enable wxPython event loop integration. (DEPRECATED, use --gui wx)""")
         paa('--q4thread', '--qthread', '-q4thread', '-qthread',
             action='store_true', dest='Global.q4thread',
             help=
             """Enable Qt4 event loop integration. Qt3 is no longer supported.
             (DEPRECATED, use --gui qt)""")
         paa('--gthread', '-gthread',
             action='store_true', dest='Global.gthread',
             help=
             """Enable GTK event loop integration. (DEPRECATED, use --gui gtk)""")
 
 
 #-----------------------------------------------------------------------------
 # Crash handler for this application
 #-----------------------------------------------------------------------------
 
 
 _message_template = """\
 Oops, $self.app_name crashed. We do our best to make it stable, but...
 
 A crash report was automatically generated with the following information:
   - A verbatim copy of the crash traceback.
   - A copy of your input history during this session.
   - Data on your current $self.app_name configuration.
 
 It was left in the file named:
 \t'$self.crash_report_fname'
 If you can email this file to the developers, the information in it will help
 them in understanding and correcting the problem.
 
 You can mail it to: $self.contact_name at $self.contact_email
 with the subject '$self.app_name Crash Report'.
 
 If you want to do it now, the following command will work (under Unix):
 mail -s '$self.app_name Crash Report' $self.contact_email < $self.crash_report_fname
 
 To ensure accurate tracking of this issue, please file a report about it at:
 $self.bug_tracker
 """
 
 class IPAppCrashHandler(CrashHandler):
     """sys.excepthook for IPython itself, leaves a detailed report on disk."""
 
     message_template = _message_template
 
     def __init__(self, app):
         contact_name = release.authors['Fernando'][0]
         contact_email = release.authors['Fernando'][1]
         bug_tracker = 'https://bugs.launchpad.net/ipython/+filebug'
         super(IPAppCrashHandler,self).__init__(
             app, contact_name, contact_email, bug_tracker
         )
 
     def make_report(self,traceback):
         """Return a string containing a crash report."""
 
         sec_sep = self.section_sep
         # Start with parent report
         report = [super(IPAppCrashHandler, self).make_report(traceback)]
         # Add interactive-specific info we may have
         rpt_add = report.append
         try:
             rpt_add(sec_sep+"History of session input:")
             for line in self.app.shell.user_ns['_ih']:
                 rpt_add(line)
             rpt_add('\n*** Last line of input (may not be in above history):\n')
             rpt_add(self.app.shell._last_input_line+'\n')
         except:
             pass
 
         return ''.join(report)
 
 
 #-----------------------------------------------------------------------------
 # Main classes and functions
 #-----------------------------------------------------------------------------
 
 class IPythonApp(Application):
     name = u'ipython'
     #: argparse formats better the 'usage' than the 'description' field
     description = None
     usage = usage.cl_usage
     command_line_loader = IPAppConfigLoader
     default_config_file_name = default_config_file_name
     crash_handler_class = IPAppCrashHandler
 
     def create_default_config(self):
         super(IPythonApp, self).create_default_config()
         # Eliminate multiple lookups
         Global = self.default_config.Global
 
         # Set all default values
         Global.display_banner = True
         
         # If the -c flag is given or a file is given to run at the cmd line
         # like "ipython foo.py", normally we exit without starting the main
         # loop.  The force_interact config variable allows a user to override
         # this and interact.  It is also set by the -i cmd line flag, just
         # like Python.
         Global.force_interact = False
 
         # By default always interact by starting the IPython mainloop.
         Global.interact = True
 
         # No GUI integration by default
         Global.gui = False
         # Pylab off by default
         Global.pylab = False
 
         # Deprecated versions of gui support that used threading, we support
         # them just for bacwards compatibility as an alternate spelling for
         # '--gui X'
         Global.qthread = False
         Global.q4thread = False
         Global.wthread = False
         Global.gthread = False
 
     def load_file_config(self):
         if hasattr(self.command_line_config.Global, 'quick'):
             if self.command_line_config.Global.quick:
                 self.file_config = Config()
                 return
         super(IPythonApp, self).load_file_config()
 
     def post_load_file_config(self):
         if hasattr(self.command_line_config.Global, 'extra_extension'):
             if not hasattr(self.file_config.Global, 'extensions'):
                 self.file_config.Global.extensions = []
             self.file_config.Global.extensions.append(
                 self.command_line_config.Global.extra_extension)
             del self.command_line_config.Global.extra_extension
 
     def pre_construct(self):
         config = self.master_config
 
         if hasattr(config.Global, 'classic'):
             if config.Global.classic:
                 config.InteractiveShell.cache_size = 0
                 config.InteractiveShell.pprint = 0
                 config.InteractiveShell.prompt_in1 = '>>> '
                 config.InteractiveShell.prompt_in2 = '... '
                 config.InteractiveShell.prompt_out = ''
                 config.InteractiveShell.separate_in = \
                     config.InteractiveShell.separate_out = \
                     config.InteractiveShell.separate_out2 = ''
                 config.InteractiveShell.colors = 'NoColor'
                 config.InteractiveShell.xmode = 'Plain'
 
         if hasattr(config.Global, 'nosep'):
             if config.Global.nosep:
                 config.InteractiveShell.separate_in = \
                 config.InteractiveShell.separate_out = \
                 config.InteractiveShell.separate_out2 = ''
 
         # if there is code of files to run from the cmd line, don't interact
         # unless the -i flag (Global.force_interact) is true.
         code_to_run = config.Global.get('code_to_run','')
         file_to_run = False
         if self.extra_args and self.extra_args[0]:
                 file_to_run = True
         if file_to_run or code_to_run:
             if not config.Global.force_interact:
                 config.Global.interact = False
 
     def construct(self):
         # I am a little hesitant to put these into InteractiveShell itself.
         # But that might be the place for them
         sys.path.insert(0, '')
 
         # Create an InteractiveShell instance
         self.shell = InteractiveShell(None, self.master_config)
 
     def post_construct(self):
         """Do actions after construct, but before starting the app."""
         config = self.master_config
         
         # shell.display_banner should always be False for the terminal 
         # based app, because we call shell.show_banner() by hand below
         # so the banner shows *before* all extension loading stuff.
         self.shell.display_banner = False
         if config.Global.display_banner and \
             config.Global.interact:
             self.shell.show_banner()
 
         # Make sure there is a space below the banner.
         if self.log_level <= logging.INFO: print
 
         # Now a variety of things that happen after the banner is printed.
         self._enable_gui_pylab()
         self._load_extensions()
         self._run_exec_lines()
         self._run_exec_files()
         self._run_cmd_line_code()
 
     def _enable_gui_pylab(self):
         """Enable GUI event loop integration, taking pylab into account."""
         Global = self.master_config.Global
 
         # Select which gui to use
         if Global.gui:
             gui = Global.gui
         # The following are deprecated, but there's likely to be a lot of use
         # of this form out there, so we might as well support it for now.  But
         # the --gui option above takes precedence.
         elif Global.wthread:
             gui = inputhook.GUI_WX
         elif Global.qthread:
             gui = inputhook.GUI_QT
         elif Global.gthread:
             gui = inputhook.GUI_GTK
         else:
             gui = None
 
         # Using --pylab will also require gui activation, though which toolkit
         # to use may be chosen automatically based on mpl configuration.
         if Global.pylab:
             activate = self.shell.enable_pylab
             if Global.pylab == 'auto':
                 gui = None
             else:
                 gui = Global.pylab
         else:
             # Enable only GUI integration, no pylab
             activate = inputhook.enable_gui
 
         if gui or Global.pylab:
             try:
                 self.log.info("Enabling GUI event loop integration, "
                               "toolkit=%s, pylab=%s" % (gui, Global.pylab) )
                 activate(gui)
             except:
                 self.log.warn("Error in enabling GUI event loop integration:")
                 self.shell.showtraceback()
 
     def _load_extensions(self):
         """Load all IPython extensions in Global.extensions.
 
         This uses the :meth:`InteractiveShell.load_extensions` to load all
         the extensions listed in ``self.master_config.Global.extensions``.
         """
         try:
             if hasattr(self.master_config.Global, 'extensions'):
                 self.log.debug("Loading IPython extensions...")
                 extensions = self.master_config.Global.extensions
                 for ext in extensions:
                     try:
                         self.log.info("Loading IPython extension: %s" % ext)                        
                         self.shell.load_extension(ext)
                     except:
                         self.log.warn("Error in loading extension: %s" % ext)
                         self.shell.showtraceback()
         except:
             self.log.warn("Unknown error in loading extensions:")
             self.shell.showtraceback()
 
     def _run_exec_lines(self):
         """Run lines of code in Global.exec_lines in the user's namespace."""
         try:
             if hasattr(self.master_config.Global, 'exec_lines'):
                 self.log.debug("Running code from Global.exec_lines...")
                 exec_lines = self.master_config.Global.exec_lines
                 for line in exec_lines:
                     try:
-                        self.log.info("Running code in user namespace: %s" % line)
+                        self.log.info("Running code in user namespace: %s" %
+                                      line)
                         self.shell.runlines(line)
                     except:
-                        self.log.warn("Error in executing line in user namespace: %s" % line)
+                        self.log.warn("Error in executing line in user "
+                                      "namespace: %s" % line)
                         self.shell.showtraceback()
         except:
             self.log.warn("Unknown error in handling Global.exec_lines:")
             self.shell.showtraceback()
 
     def _exec_file(self, fname):
         full_filename = filefind(fname, [u'.', self.ipython_dir])
         if os.path.isfile(full_filename):
             if full_filename.endswith(u'.py'):
-                self.log.info("Running file in user namespace: %s" % full_filename)
-                self.shell.safe_execfile(full_filename, self.shell.user_ns)
+                self.log.info("Running file in user namespace: %s" %
+                              full_filename)
+                # Ensure that __file__ is always defined to match Python behavior
+                self.shell.user_ns['__file__'] = fname
+                try:
+                    self.shell.safe_execfile(full_filename, self.shell.user_ns)
+                finally:
+                    del self.shell.user_ns['__file__']
             elif full_filename.endswith('.ipy'):
-                self.log.info("Running file in user namespace: %s" % full_filename)
+                self.log.info("Running file in user namespace: %s" %
+                              full_filename)
                 self.shell.safe_execfile_ipy(full_filename)
             else:
-                self.log.warn("File does not have a .py or .ipy extension: <%s>" % full_filename)
-
+                self.log.warn("File does not have a .py or .ipy extension: <%s>"
+                               % full_filename)
     def _run_exec_files(self):
         try:
             if hasattr(self.master_config.Global, 'exec_files'):
                 self.log.debug("Running files in Global.exec_files...")
                 exec_files = self.master_config.Global.exec_files
                 for fname in exec_files:
                     self._exec_file(fname)
         except:
             self.log.warn("Unknown error in handling Global.exec_files:")
             self.shell.showtraceback()
 
     def _run_cmd_line_code(self):
         if hasattr(self.master_config.Global, 'code_to_run'):
             line = self.master_config.Global.code_to_run
             try:
-                self.log.info("Running code given at command line (-c): %s" % line)
+                self.log.info("Running code given at command line (-c): %s" %
+                              line)
                 self.shell.runlines(line)
             except:
-                self.log.warn("Error in executing line in user namespace: %s" % line)
+                self.log.warn("Error in executing line in user namespace: %s" %
+                              line)
                 self.shell.showtraceback()
             return
         # Like Python itself, ignore the second if the first of these is present
         try:
             fname = self.extra_args[0]
         except:
             pass
         else:
             try:
                 self._exec_file(fname)
             except:
-                self.log.warn("Error in executing file in user namespace: %s" % fname)
+                self.log.warn("Error in executing file in user namespace: %s" %
+                              fname)
                 self.shell.showtraceback()
 
     def start_app(self):
         if self.master_config.Global.interact:
             self.log.debug("Starting IPython's mainloop...")
             self.shell.mainloop()
         else:
             self.log.debug("IPython not interactive, start_app is no-op...")
 
 
 def load_default_config(ipython_dir=None):
     """Load the default config file from the default ipython_dir.
 
     This is useful for embedded shells.
     """
     if ipython_dir is None:
         ipython_dir = get_ipython_dir()
     cl = PyFileConfigLoader(default_config_file_name, ipython_dir)
     config = cl.load_config()
     return config
 
 
 def launch_new_instance():
     """Create and run a full blown IPython instance"""
     app = IPythonApp()
     app.start()
 
 
 if __name__ == '__main__':
     launch_new_instance()