Initial support for %pylab magic to load pylab at runtime.

Now one can type %pylab or %pylab wx to load pylab at any point in a session
(though only once, since mpl doesn't support switching gui backends).

IPython/core/application.py

@@ -1,377 +1,377 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 An application for IPython.
 
 All top-level applications should use the classes in this module for
 handling configuration and creating componenets.
 
 The job of an :class:`Application` is to create the master configuration 
 object and then create the components, passing the config to them.
 
 Authors:
 
 * Brian Granger
 * Fernando Perez
 
 Notes
 -----
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  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 logging
 import os
 import sys
 
 from IPython.core import release
 from IPython.utils.genutils import get_ipython_dir, get_ipython_package_dir
 from IPython.config.loader import (
     PyFileConfigLoader,
     ArgParseConfigLoader,
     Config,
     NoConfigDefault
 )
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 
 class BaseAppArgParseConfigLoader(ArgParseConfigLoader):
     """Default command line options for IPython based applications."""
 
     def _add_other_arguments(self):
         self.parser.add_argument('--ipython-dir', 
             dest='Global.ipython_dir',type=unicode,
             help='Set to override default location of Global.ipython_dir.',
             default=NoConfigDefault,
             metavar='Global.ipython_dir')
         self.parser.add_argument('-p', '--profile',
             dest='Global.profile',type=unicode,
             help='The string name of the ipython profile to be used.',
             default=NoConfigDefault,
             metavar='Global.profile')
         self.parser.add_argument('--log-level',
             dest="Global.log_level",type=int,
             help='Set the log level (0,10,20,30,40,50).  Default is 30.',
             default=NoConfigDefault,
             metavar='Global.log_level')
         self.parser.add_argument('--config-file',
             dest='Global.config_file',type=unicode,
             help='Set the config file name to override default.',
             default=NoConfigDefault,
             metavar='Global.config_file')
 
 
 class ApplicationError(Exception):
     pass
 
 
 class Application(object):
     """Load a config, construct components and set them running."""
 
     name = u'ipython'
     description = 'IPython: an enhanced interactive Python shell.'
 
     config_file_name = u'ipython_config.py'
     # Track the default and actual separately because some messages are
     # only printed if we aren't using the default.
     default_config_file_name = config_file_name
     default_log_level = logging.WARN
     # Set by --profile option
     profile_name = None
     # User's ipython directory, typically ~/.ipython/
     ipython_dir = None
 
     # Private attributes
     _exiting = False
 
     def __init__(self):
         self.init_logger()
 
     def init_logger(self):
         self.log = logging.getLogger(self.__class__.__name__)
         # This is used as the default until the command line arguments are read.
         self.log.setLevel(self.default_log_level)
         self._log_handler = logging.StreamHandler()
         self._log_formatter = logging.Formatter("[%(name)s] %(message)s")
         self._log_handler.setFormatter(self._log_formatter)
         self.log.addHandler(self._log_handler)
 
     def _set_log_level(self, level):
         self.log.setLevel(level)
 
     def _get_log_level(self):
         return self.log.level
 
     log_level = property(_get_log_level, _set_log_level)
 
     def start(self):
         """Start the application."""
         self.attempt(self.create_default_config)
         self.log_default_config()
         self.set_default_config_log_level()
         self.attempt(self.pre_load_command_line_config)
         self.attempt(self.load_command_line_config, action='abort')
         self.set_command_line_config_log_level()
         self.attempt(self.post_load_command_line_config)
         self.log_command_line_config()
         self.attempt(self.find_ipython_dir)
         self.attempt(self.find_resources)
         self.attempt(self.find_config_file_name)
         self.attempt(self.find_config_file_paths)
         self.attempt(self.pre_load_file_config)
         self.attempt(self.load_file_config)
         self.set_file_config_log_level()
         self.attempt(self.post_load_file_config)
         self.log_file_config()
         self.attempt(self.merge_configs)
         self.log_master_config()
         self.attempt(self.pre_construct)
         self.attempt(self.construct)
         self.attempt(self.post_construct)
         self.attempt(self.start_app)
 
     #-------------------------------------------------------------------------
     # Various stages of Application creation
     #-------------------------------------------------------------------------
 
     def create_default_config(self):
         """Create defaults that can't be set elsewhere.
 
         For the most part, we try to set default in the class attributes
         of Components.  But, defaults the top-level Application (which is
         not a HasTraitlets or Component) are not set in this way.  Instead
         we set them here.  The Global section is for variables like this that
         don't belong to a particular component.
         """
         self.default_config = Config()
         self.default_config.Global.ipython_dir = get_ipython_dir()
         self.default_config.Global.log_level = self.log_level
 
     def log_default_config(self):
         self.log.debug('Default config loaded:')
         self.log.debug(repr(self.default_config))
 
     def set_default_config_log_level(self):
         try:
             self.log_level = self.default_config.Global.log_level
         except AttributeError:
             # Fallback to the default_log_level class attribute
             pass
 
     def create_command_line_config(self):
         """Create and return a command line config loader."""
         return BaseAppArgParseConfigLoader(
             description=self.description, 
             version=release.version
         )
 
     def pre_load_command_line_config(self):
         """Do actions just before loading the command line config."""
         pass
 
     def load_command_line_config(self):
         """Load the command line config."""
         loader = self.create_command_line_config()
         self.command_line_config = loader.load_config()
         self.extra_args = loader.get_extra_args()
 
     def set_command_line_config_log_level(self):
         try:
             self.log_level = self.command_line_config.Global.log_level
         except AttributeError:
             pass
 
     def post_load_command_line_config(self):
         """Do actions just after loading the command line config."""
         pass
 
     def log_command_line_config(self):
         self.log.debug("Command line config loaded:")
         self.log.debug(repr(self.command_line_config))
 
     def find_ipython_dir(self):
         """Set the IPython directory.
 
         This sets ``self.ipython_dir``, but the actual value that is passed to
         the application is kept in either ``self.default_config`` or
         ``self.command_line_config``.  This also adds ``self.ipython_dir`` to
         ``sys.path`` so config files there can be referenced by other config
         files.
         """
 
         try:
             self.ipython_dir = self.command_line_config.Global.ipython_dir
         except AttributeError:
             self.ipython_dir = self.default_config.Global.ipython_dir
         sys.path.append(os.path.abspath(self.ipython_dir))
         if not os.path.isdir(self.ipython_dir):
             os.makedirs(self.ipython_dir, mode=0777)
         self.log.debug("IPYTHON_DIR set to: %s" % self.ipython_dir)
 
     def find_resources(self):
         """Find other resources that need to be in place.
 
         Things like cluster directories need to be in place to find the
         config file.  These happen right after the IPython directory has
         been set.
         """
         pass
 
     def find_config_file_name(self):
         """Find the config file name for this application.
 
         This must set ``self.config_file_name`` to the filename of the
         config file to use (just the filename). The search paths for the
         config file are set in :meth:`find_config_file_paths` and then passed
         to the config file loader where they are resolved to an absolute path.
 
         If a profile has been set at the command line, this will resolve it.
         """
 
         try:
             self.config_file_name = self.command_line_config.Global.config_file
         except AttributeError:
             pass
 
         try:
             self.profile_name = self.command_line_config.Global.profile
         except AttributeError:
             pass
         else:
             name_parts = self.config_file_name.split('.')
             name_parts.insert(1, u'_' + self.profile_name + u'.')
             self.config_file_name = ''.join(name_parts)
 
     def find_config_file_paths(self):
         """Set the search paths for resolving the config file.
 
         This must set ``self.config_file_paths`` to a sequence of search
         paths to pass to the config file loader.
         """
         # Include our own profiles directory last, so that users can still find
         # our shipped copies of builtin profiles even if they don't have them
         # in their local ipython directory.
         prof_dir = os.path.join(get_ipython_package_dir(), 'config', 'profile')
-        self.config_file_paths = (os.getcwd(), self.ipython_dir,prof_dir)
+        self.config_file_paths = (os.getcwd(), self.ipython_dir, prof_dir)
 
     def pre_load_file_config(self):
         """Do actions before the config file is loaded."""
         pass
 
     def load_file_config(self):
         """Load the config file.
         
         This tries to load the config file from disk.  If successful, the
         ``CONFIG_FILE`` config variable is set to the resolved config file
         location.  If not successful, an empty config is used.
         """
         self.log.debug("Attempting to load config file: %s" %
                        self.config_file_name)
         loader = PyFileConfigLoader(self.config_file_name,
                                     path=self.config_file_paths)
         try:
             self.file_config = loader.load_config()
             self.file_config.Global.config_file = loader.full_filename
         except IOError:
             # Only warn if the default config file was NOT being used.
             if not self.config_file_name==self.default_config_file_name:
                 self.log.warn("Config file not found, skipping: %s" %
                                self.config_file_name, exc_info=True)
             self.file_config = Config()
         except:
             self.log.warn("Error loading config file: %s" %
                           self.config_file_name, exc_info=True)
             self.file_config = Config()
 
     def set_file_config_log_level(self):
         # We need to keeep self.log_level updated.  But we only use the value
         # of the file_config if a value was not specified at the command
         # line, because the command line overrides everything.
         if not hasattr(self.command_line_config.Global, 'log_level'):
             try:
                 self.log_level = self.file_config.Global.log_level
             except AttributeError:
                 pass # Use existing value
 
     def post_load_file_config(self):
         """Do actions after the config file is loaded."""
         pass
 
     def log_file_config(self):
         if hasattr(self.file_config.Global, 'config_file'):
             self.log.debug("Config file loaded: %s" %
                            self.file_config.Global.config_file)
             self.log.debug(repr(self.file_config))
 
     def merge_configs(self):
         """Merge the default, command line and file config objects."""
         config = Config()
         config._merge(self.default_config)
         config._merge(self.file_config)
         config._merge(self.command_line_config)
         self.master_config = config
 
     def log_master_config(self):
         self.log.debug("Master config created:")
         self.log.debug(repr(self.master_config))
 
     def pre_construct(self):
         """Do actions after the config has been built, but before construct."""
         pass
 
     def construct(self):
         """Construct the main components that make up this app."""
         self.log.debug("Constructing components for application")
 
     def post_construct(self):
         """Do actions after construct, but before starting the app."""
         pass
 
     def start_app(self):
         """Actually start the app."""
         self.log.debug("Starting application")
 
     #-------------------------------------------------------------------------
     # Utility methods
     #-------------------------------------------------------------------------
 
     def abort(self):
         """Abort the starting of the application."""
         if self._exiting:
             pass
         else:
             self.log.critical("Aborting application: %s" % self.name, exc_info=True)
             self._exiting = True
             sys.exit(1)
 
     def exit(self, exit_status=0):
         if self._exiting:
             pass
         else:
             self.log.debug("Exiting application: %s" % self.name)
             self._exiting = True
             sys.exit(exit_status)
 
     def attempt(self, func, action='abort'):
         try:
             func()
         except SystemExit:
             raise
         except:
             if action == 'abort':
                 self.abort()
             elif action == 'exit':
                 self.exit(0)