remove profile awareness from load_subconfig

move that to IPython-specific subclass

IPython/config/application.py

@@ -1,621 +1,624 b''
 # encoding: utf-8
 """A base class for a configurable application."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import print_function
 
 import json
 import logging
 import os
 import re
 import sys
 from copy import deepcopy
 from collections import defaultdict
 
 from decorator import decorator
 
 from IPython.config.configurable import SingletonConfigurable
 from IPython.config.loader import (
     KVArgParseConfigLoader, PyFileConfigLoader, Config, ArgumentError, ConfigFileNotFound, JSONFileConfigLoader
 )
 
 from IPython.utils.traitlets import (
     Unicode, List, Enum, Dict, Instance, TraitError
 )
 from IPython.utils.importstring import import_item
 from IPython.utils.text import indent, wrap_paragraphs, dedent
 from IPython.utils import py3compat
 from IPython.utils.py3compat import string_types, iteritems
 
 #-----------------------------------------------------------------------------
 # Descriptions for the various sections
 #-----------------------------------------------------------------------------
 
 # merge flags&aliases into options
 option_description = """
 Arguments that take values are actually convenience aliases to full
 Configurables, whose aliases are listed on the help line. For more information
 on full configurables, see '--help-all'.
 """.strip() # trim newlines of front and back
 
 keyvalue_description = """
 Parameters are set from command-line arguments of the form:
 `--Class.trait=value`.
 This line is evaluated in Python, so simple expressions are allowed, e.g.::
 `--C.a='range(3)'` For setting C.a=[0,1,2].
 """.strip() # trim newlines of front and back
 
 # sys.argv can be missing, for example when python is embedded. See the docs
 # for details: http://docs.python.org/2/c-api/intro.html#embedding-python
 if not hasattr(sys, "argv"):
     sys.argv = [""]
 
 subcommand_description = """
 Subcommands are launched as `{app} cmd [args]`. For information on using
 subcommand 'cmd', do: `{app} cmd -h`.
 """
 # get running program name
 
 #-----------------------------------------------------------------------------
 # Application class
 #-----------------------------------------------------------------------------
 
 @decorator
 def catch_config_error(method, app, *args, **kwargs):
     """Method decorator for catching invalid config (Trait/ArgumentErrors) during init.
 
     On a TraitError (generally caused by bad config), this will print the trait's
     message, and exit the app.
     
     For use on init methods, to prevent invoking excepthook on invalid input.
     """
     try:
         return method(app, *args, **kwargs)
     except (TraitError, ArgumentError) as e:
         app.print_help()
         app.log.fatal("Bad config encountered during initialization:")
         app.log.fatal(str(e))
         app.log.debug("Config at the time: %s", app.config)
         app.exit(1)
 
 
 class ApplicationError(Exception):
     pass
 
 class LevelFormatter(logging.Formatter):
     """Formatter with additional `highlevel` record
     
     This field is empty if log level is less than highlevel_limit,
     otherwise it is formatted with self.highlevel_format.
     
     Useful for adding 'WARNING' to warning messages,
     without adding 'INFO' to info, etc.
     """
     highlevel_limit = logging.WARN
     highlevel_format = " %(levelname)s |"
     
     def format(self, record):
         if record.levelno >= self.highlevel_limit:
             record.highlevel = self.highlevel_format % record.__dict__
         else:
             record.highlevel = ""
         return super(LevelFormatter, self).format(record)
             
 
 class Application(SingletonConfigurable):
     """A singleton application with full configuration support."""
 
     # The name of the application, will usually match the name of the command
     # line application
     name = Unicode(u'application')
 
     # The description of the application that is printed at the beginning
     # of the help.
     description = Unicode(u'This is an application.')
     # default section descriptions
     option_description = Unicode(option_description)
     keyvalue_description = Unicode(keyvalue_description)
     subcommand_description = Unicode(subcommand_description)
+    
+    python_config_loader_class = PyFileConfigLoader
+    json_config_loader_class = JSONFileConfigLoader
 
     # The usage and example string that goes at the end of the help string.
     examples = Unicode()
 
     # A sequence of Configurable subclasses whose config=True attributes will
     # be exposed at the command line.
     classes = []
     @property
     def _help_classes(self):
         """Define `App.help_classes` if CLI classes should differ from config file classes"""
         return getattr(self, 'help_classes', self.classes)
     
     @property
     def _config_classes(self):
         """Define `App.config_classes` if config file classes should differ from CLI classes."""
         return getattr(self, 'config_classes', self.classes)
 
     # The version string of this application.
     version = Unicode(u'0.0')
     
     # the argv used to initialize the application
     argv = List()
 
     # The log level for the application
     log_level = Enum((0,10,20,30,40,50,'DEBUG','INFO','WARN','ERROR','CRITICAL'),
                     default_value=logging.WARN,
                     config=True,
                     help="Set the log level by value or name.")
     def _log_level_changed(self, name, old, new):
         """Adjust the log level when log_level is set."""
         if isinstance(new, string_types):
             new = getattr(logging, new)
             self.log_level = new
         self.log.setLevel(new)
     
     _log_formatter_cls = LevelFormatter
     
     log_datefmt = Unicode("%Y-%m-%d %H:%M:%S", config=True,
         help="The date format used by logging formatters for %(asctime)s"
     )
     def _log_datefmt_changed(self, name, old, new):
         self._log_format_changed('log_format', self.log_format, self.log_format)
     
     log_format = Unicode("[%(name)s]%(highlevel)s %(message)s", config=True,
         help="The Logging format template",
     )
     def _log_format_changed(self, name, old, new):
         """Change the log formatter when log_format is set."""
         _log_handler = self.log.handlers[0]
         _log_formatter = self._log_formatter_cls(fmt=new, datefmt=self.log_datefmt)
         _log_handler.setFormatter(_log_formatter)
     
 
     log = Instance(logging.Logger)
     def _log_default(self):
         """Start logging for this application.
 
         The default is to log to stderr using a StreamHandler, if no default
         handler already exists.  The log level starts at logging.WARN, but this
         can be adjusted by setting the ``log_level`` attribute.
         """
         log = logging.getLogger(self.__class__.__name__)
         log.setLevel(self.log_level)
         log.propagate = False
         _log = log # copied from Logger.hasHandlers() (new in Python 3.2)
         while _log:
             if _log.handlers:
                 return log
             if not _log.propagate:
                 break
             else:
                 _log = _log.parent
         if sys.executable.endswith('pythonw.exe'):
             # this should really go to a file, but file-logging is only
             # hooked up in parallel applications
             _log_handler = logging.StreamHandler(open(os.devnull, 'w'))
         else:
             _log_handler = logging.StreamHandler()
         _log_formatter = self._log_formatter_cls(fmt=self.log_format, datefmt=self.log_datefmt)
         _log_handler.setFormatter(_log_formatter)
         log.addHandler(_log_handler)
         return log
 
     # the alias map for configurables
     aliases = Dict({'log-level' : 'Application.log_level'})
 
     # flags for loading Configurables or store_const style flags
     # flags are loaded from this dict by '--key' flags
     # this must be a dict of two-tuples, the first element being the Config/dict
     # and the second being the help string for the flag
     flags = Dict()
     def _flags_changed(self, name, old, new):
         """ensure flags dict is valid"""
         for key,value in iteritems(new):
             assert len(value) == 2, "Bad flag: %r:%s"%(key,value)
             assert isinstance(value[0], (dict, Config)), "Bad flag: %r:%s"%(key,value)
             assert isinstance(value[1], string_types), "Bad flag: %r:%s"%(key,value)
 
 
     # subcommands for launching other applications
     # if this is not empty, this will be a parent Application
     # this must be a dict of two-tuples,
     # the first element being the application class/import string
     # and the second being the help string for the subcommand
     subcommands = Dict()
     # parse_command_line will initialize a subapp, if requested
     subapp = Instance('IPython.config.application.Application', allow_none=True)
 
     # extra command-line arguments that don't set config values
     extra_args = List(Unicode)
 
 
     def __init__(self, **kwargs):
         SingletonConfigurable.__init__(self, **kwargs)
         # Ensure my class is in self.classes, so my attributes appear in command line
         # options and config files.
         if self.__class__ not in self.classes:
             self.classes.insert(0, self.__class__)
 
     def _config_changed(self, name, old, new):
         SingletonConfigurable._config_changed(self, name, old, new)
         self.log.debug('Config changed:')
         self.log.debug(repr(new))
 
     @catch_config_error
     def initialize(self, argv=None):
         """Do the basic steps to configure me.
 
         Override in subclasses.
         """
         self.parse_command_line(argv)
 
 
     def start(self):
         """Start the app mainloop.
 
         Override in subclasses.
         """
         if self.subapp is not None:
             return self.subapp.start()
 
     def print_alias_help(self):
         """Print the alias part of the help."""
         if not self.aliases:
             return
 
         lines = []
         classdict = {}
         for cls in self._help_classes:
             # include all parents (up to, but excluding Configurable) in available names
             for c in cls.mro()[:-3]:
                 classdict[c.__name__] = c
 
         for alias, longname in iteritems(self.aliases):
             classname, traitname = longname.split('.',1)
             cls = classdict[classname]
 
             trait = cls.class_traits(config=True)[traitname]
             help = cls.class_get_trait_help(trait).splitlines()
             # reformat first line
             help[0] = help[0].replace(longname, alias) + ' (%s)'%longname
             if len(alias) == 1:
                 help[0] = help[0].replace('--%s='%alias, '-%s '%alias)
             lines.extend(help)
         # lines.append('')
         print(os.linesep.join(lines))
 
     def print_flag_help(self):
         """Print the flag part of the help."""
         if not self.flags:
             return
 
         lines = []
         for m, (cfg,help) in iteritems(self.flags):
             prefix = '--' if len(m) > 1 else '-'
             lines.append(prefix+m)
             lines.append(indent(dedent(help.strip())))
         # lines.append('')
         print(os.linesep.join(lines))
 
     def print_options(self):
         if not self.flags and not self.aliases:
             return
         lines = ['Options']
         lines.append('-'*len(lines[0]))
         lines.append('')
         for p in wrap_paragraphs(self.option_description):
             lines.append(p)
             lines.append('')
         print(os.linesep.join(lines))
         self.print_flag_help()
         self.print_alias_help()
         print()
 
     def print_subcommands(self):
         """Print the subcommand part of the help."""
         if not self.subcommands:
             return
 
         lines = ["Subcommands"]
         lines.append('-'*len(lines[0]))
         lines.append('')
         for p in wrap_paragraphs(self.subcommand_description.format(
                     app=self.name)):
             lines.append(p)
             lines.append('')
         for subc, (cls, help) in iteritems(self.subcommands):
             lines.append(subc)
             if help:
                 lines.append(indent(dedent(help.strip())))
         lines.append('')
         print(os.linesep.join(lines))
 
     def print_help(self, classes=False):
         """Print the help for each Configurable class in self.classes.
 
         If classes=False (the default), only flags and aliases are printed.
         """
         self.print_description()
         self.print_subcommands()
         self.print_options()
 
         if classes:
             help_classes = self._help_classes
             if help_classes:
                 print("Class parameters")
                 print("----------------")
                 print()
                 for p in wrap_paragraphs(self.keyvalue_description):
                     print(p)
                     print()
 
             for cls in help_classes:
                 cls.class_print_help()
                 print()
         else:
             print("To see all available configurables, use `--help-all`")
             print()
 
         self.print_examples()
 
 
     def print_description(self):
         """Print the application description."""
         for p in wrap_paragraphs(self.description):
             print(p)
             print()
 
     def print_examples(self):
         """Print usage and examples.
 
         This usage string goes at the end of the command line help string
         and should contain examples of the application's usage.
         """
         if self.examples:
             print("Examples")
             print("--------")
             print()
             print(indent(dedent(self.examples.strip())))
             print()
 
     def print_version(self):
         """Print the version string."""
         print(self.version)
 
     def update_config(self, config):
         """Fire the traits events when the config is updated."""
         # Save a copy of the current config.
         newconfig = deepcopy(self.config)
         # Merge the new config into the current one.
         newconfig.merge(config)
         # Save the combined config as self.config, which triggers the traits
         # events.
         self.config = newconfig
 
     @catch_config_error
     def initialize_subcommand(self, subc, argv=None):
         """Initialize a subcommand with argv."""
         subapp,help = self.subcommands.get(subc)
 
         if isinstance(subapp, string_types):
             subapp = import_item(subapp)
 
         # clear existing instances
         self.__class__.clear_instance()
         # instantiate
         self.subapp = subapp.instance(config=self.config)
         # and initialize subapp
         self.subapp.initialize(argv)
     
     def flatten_flags(self):
         """flatten flags and aliases, so cl-args override as expected.
         
         This prevents issues such as an alias pointing to InteractiveShell,
         but a config file setting the same trait in TerminalInteraciveShell
         getting inappropriate priority over the command-line arg.
 
         Only aliases with exactly one descendent in the class list
         will be promoted.
         
         """
         # build a tree of classes in our list that inherit from a particular
         # it will be a dict by parent classname of classes in our list
         # that are descendents
         mro_tree = defaultdict(list)
         for cls in self._help_classes:
             clsname = cls.__name__
             for parent in cls.mro()[1:-3]:
                 # exclude cls itself and Configurable,HasTraits,object
                 mro_tree[parent.__name__].append(clsname)
         # flatten aliases, which have the form:
         # { 'alias' : 'Class.trait' }
         aliases = {}
         for alias, cls_trait in iteritems(self.aliases):
             cls,trait = cls_trait.split('.',1)
             children = mro_tree[cls]
             if len(children) == 1:
                 # exactly one descendent, promote alias
                 cls = children[0]
             aliases[alias] = '.'.join([cls,trait])
         
         # flatten flags, which are of the form:
         # { 'key' : ({'Cls' : {'trait' : value}}, 'help')}
         flags = {}
         for key, (flagdict, help) in iteritems(self.flags):
             newflag = {}
             for cls, subdict in iteritems(flagdict):
                 children = mro_tree[cls]
                 # exactly one descendent, promote flag section
                 if len(children) == 1:
                     cls = children[0]
                 newflag[cls] = subdict
             flags[key] = (newflag, help)
         return flags, aliases
 
     @catch_config_error
     def parse_command_line(self, argv=None):
         """Parse the command line arguments."""
         argv = sys.argv[1:] if argv is None else argv
         self.argv = [ py3compat.cast_unicode(arg) for arg in argv ]
         
         if argv and argv[0] == 'help':
             # turn `ipython help notebook` into `ipython notebook -h`
             argv = argv[1:] + ['-h']
 
         if self.subcommands and len(argv) > 0:
             # we have subcommands, and one may have been specified
             subc, subargv = argv[0], argv[1:]
             if re.match(r'^\w(\-?\w)*$', subc) and subc in self.subcommands:
                 # it's a subcommand, and *not* a flag or class parameter
                 return self.initialize_subcommand(subc, subargv)
 
         # Arguments after a '--' argument are for the script IPython may be
         # about to run, not IPython iteslf. For arguments parsed here (help and
         # version), we want to only search the arguments up to the first
         # occurrence of '--', which we're calling interpreted_argv.
         try:
             interpreted_argv = argv[:argv.index('--')]
         except ValueError:
             interpreted_argv = argv
 
         if any(x in interpreted_argv for x in ('-h', '--help-all', '--help')):
             self.print_help('--help-all' in interpreted_argv)
             self.exit(0)
 
         if '--version' in interpreted_argv or '-V' in interpreted_argv:
             self.print_version()
             self.exit(0)
         
         # flatten flags&aliases, so cl-args get appropriate priority:
         flags,aliases = self.flatten_flags()
         loader = KVArgParseConfigLoader(argv=argv, aliases=aliases,
                                         flags=flags, log=self.log)
         config = loader.load_config()
         self.update_config(config)
         # store unparsed args in extra_args
         self.extra_args = loader.extra_args
 
     @classmethod
     def _load_config_files(cls, basefilename, path=None, log=None):
         """Load config files (py,json) by filename and path.
 
         yield each config object in turn.
         """
         
         if not isinstance(path, list):
             path = [path]
         for path in path[::-1]:
             # path list is in descending priority order, so load files backwards:
-            pyloader = PyFileConfigLoader(basefilename+'.py', path=path, log=log)
-            jsonloader = JSONFileConfigLoader(basefilename+'.json', path=path, log=log)
+            pyloader = cls.python_config_loader_class(basefilename+'.py', path=path, log=log)
+            jsonloader = cls.json_config_loader_class(basefilename+'.json', path=path, log=log)
             config = None
             for loader in [pyloader, jsonloader]:
                 try:
                     config = loader.load_config()
                 except ConfigFileNotFound:
                     pass
                 except Exception:
                     # try to get the full filename, but it will be empty in the
                     # unlikely event that the error raised before filefind finished
                     filename = loader.full_filename or basefilename
                     # problem while running the file
                     if log:
                         log.error("Exception while loading config file %s",
                                 filename, exc_info=True)
                 else:
                     if log:
                         log.debug("Loaded config file: %s", loader.full_filename)
                 if config:
                      yield config
 
         raise StopIteration
 
 
     @catch_config_error
     def load_config_file(self, filename, path=None):
         """Load config files by filename and path."""
         filename, ext = os.path.splitext(filename)
         loaded = []
         for config in self._load_config_files(filename, path=path, log=self.log):
             loaded.append(config)
             self.update_config(config)
         if len(loaded) > 1:
             collisions = loaded[0].collisions(loaded[1])
             if collisions:
                 self.log.warn("Collisions detected in {0}.py and {0}.json config files."
                               " {0}.json has higher priority: {1}".format(
                               filename, json.dumps(collisions, indent=2),
                 ))
 
 
     def generate_config_file(self):
         """generate default config file from Configurables"""
         lines = ["# Configuration file for %s."%self.name]
         lines.append('')
         lines.append('c = get_config()')
         lines.append('')
         for cls in self._config_classes:
             lines.append(cls.class_config_section())
         return '\n'.join(lines)
 
     def exit(self, exit_status=0):
         self.log.debug("Exiting application: %s" % self.name)
         sys.exit(exit_status)
 
     @classmethod
     def launch_instance(cls, argv=None, **kwargs):
         """Launch a global instance of this Application
         
         If a global instance already exists, this reinitializes and starts it
         """
         app = cls.instance(**kwargs)
         app.initialize(argv)
         app.start()
 
 #-----------------------------------------------------------------------------
 # utility functions, for convenience
 #-----------------------------------------------------------------------------
 
 def boolean_flag(name, configurable, set_help='', unset_help=''):
     """Helper for building basic --trait, --no-trait flags.
 
     Parameters
     ----------
 
     name : str
         The name of the flag.
     configurable : str
         The 'Class.trait' string of the trait to be set/unset with the flag
     set_help : unicode
         help string for --name flag
     unset_help : unicode
         help string for --no-name flag
 
     Returns
     -------
 
     cfg : dict
         A dict with two keys: 'name', and 'no-name', for setting and unsetting
         the trait, respectively.
     """
     # default helpstrings
     set_help = set_help or "set %s=True"%configurable
     unset_help = unset_help or "set %s=False"%configurable
 
     cls,trait = configurable.split('.')
 
     setter = {cls : {trait : True}}
     unsetter = {cls : {trait : False}}
     return {name : (setter, set_help), 'no-'+name : (unsetter, unset_help)}
 
 
 def get_config():
     """Get the config object for the global Application instance, if there is one
     
     otherwise return an empty config object
     """
     if Application.initialized():
         return Application.instance().config
     else:
         return Config()

IPython/config/loader.py

@@ -1,858 +1,835 b''
 # encoding: utf-8
 """A simple configuration system."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import argparse
 import copy
 import logging
 import os
 import re
 import sys
 import json
 from ast import literal_eval
 
 from IPython.utils.path import filefind, get_ipython_dir
 from IPython.utils import py3compat
 from IPython.utils.encoding import DEFAULT_ENCODING
 from IPython.utils.py3compat import unicode_type, iteritems
 from IPython.utils.traitlets import HasTraits, List, Any
 
 #-----------------------------------------------------------------------------
 # Exceptions
 #-----------------------------------------------------------------------------
 
 
 class ConfigError(Exception):
     pass
 
 class ConfigLoaderError(ConfigError):
     pass
 
 class ConfigFileNotFound(ConfigError):
     pass
 
 class ArgumentError(ConfigLoaderError):
     pass
 
 #-----------------------------------------------------------------------------
 # Argparse fix
 #-----------------------------------------------------------------------------
 
 # Unfortunately argparse by default prints help messages to stderr instead of
 # stdout.  This makes it annoying to capture long help screens at the command
 # line, since one must know how to pipe stderr, which many users don't know how
 # to do.  So we override the print_help method with one that defaults to
 # stdout and use our class instead.
 
 class ArgumentParser(argparse.ArgumentParser):
     """Simple argparse subclass that prints help to stdout by default."""
 
     def print_help(self, file=None):
         if file is None:
             file = sys.stdout
         return super(ArgumentParser, self).print_help(file)
 
     print_help.__doc__ = argparse.ArgumentParser.print_help.__doc__
 
 #-----------------------------------------------------------------------------
 # Config class for holding config information
 #-----------------------------------------------------------------------------
 
 class LazyConfigValue(HasTraits):
     """Proxy object for exposing methods on configurable containers
     
     Exposes:
     
     - append, extend, insert on lists
     - update on dicts
     - update, add on sets
     """
     
     _value = None
     
     # list methods
     _extend = List()
     _prepend = List()
     
     def append(self, obj):
         self._extend.append(obj)
     
     def extend(self, other):
         self._extend.extend(other)
     
     def prepend(self, other):
         """like list.extend, but for the front"""
         self._prepend[:0] = other
     
     _inserts = List()
     def insert(self, index, other):
         if not isinstance(index, int):
             raise TypeError("An integer is required")
         self._inserts.append((index, other))
     
     # dict methods
     # update is used for both dict and set
     _update = Any()
     def update(self, other):
         if self._update is None:
             if isinstance(other, dict):
                 self._update = {}
             else:
                 self._update = set()
         self._update.update(other)
     
     # set methods
     def add(self, obj):
         self.update({obj})
     
     def get_value(self, initial):
         """construct the value from the initial one
         
         after applying any insert / extend / update changes
         """
         if self._value is not None:
             return self._value
         value = copy.deepcopy(initial)
         if isinstance(value, list):
             for idx, obj in self._inserts:
                 value.insert(idx, obj)
             value[:0] = self._prepend
             value.extend(self._extend)
         
         elif isinstance(value, dict):
             if self._update:
                 value.update(self._update)
         elif isinstance(value, set):
             if self._update:
                 value.update(self._update)
         self._value = value
         return value
     
     def to_dict(self):
         """return JSONable dict form of my data
         
         Currently update as dict or set, extend, prepend as lists, and inserts as list of tuples.
         """
         d = {}
         if self._update:
             d['update'] = self._update
         if self._extend:
             d['extend'] = self._extend
         if self._prepend:
             d['prepend'] = self._prepend
         elif self._inserts:
             d['inserts'] = self._inserts
         return d
 
 
 def _is_section_key(key):
     """Is a Config key a section name (does it start with a capital)?"""
     if key and key[0].upper()==key[0] and not key.startswith('_'):
         return True
     else:
         return False
 
 
 class Config(dict):
     """An attribute based dict that can do smart merges."""
 
     def __init__(self, *args, **kwds):
         dict.__init__(self, *args, **kwds)
         self._ensure_subconfig()
     
     def _ensure_subconfig(self):
         """ensure that sub-dicts that should be Config objects are
         
         casts dicts that are under section keys to Config objects,
         which is necessary for constructing Config objects from dict literals.
         """
         for key in self:
             obj = self[key]
             if _is_section_key(key) \
                     and isinstance(obj, dict) \
                     and not isinstance(obj, Config):
                 setattr(self, key, Config(obj))
     
     def _merge(self, other):
         """deprecated alias, use Config.merge()"""
         self.merge(other)
     
     def merge(self, other):
         """merge another config object into this one"""
         to_update = {}
         for k, v in iteritems(other):
             if k not in self:
                 to_update[k] = copy.deepcopy(v)
             else: # I have this key
                 if isinstance(v, Config) and isinstance(self[k], Config):
                     # Recursively merge common sub Configs
                     self[k].merge(v)
                 else:
                     # Plain updates for non-Configs
                     to_update[k] = copy.deepcopy(v)
 
         self.update(to_update)
     
     def collisions(self, other):
         """Check for collisions between two config objects.
         
         Returns a dict of the form {"Class": {"trait": "collision message"}}`,
         indicating which values have been ignored.
         
         An empty dict indicates no collisions.
         """
         collisions = {}
         for section in self:
             if section not in other:
                 continue
             mine = self[section]
             theirs = other[section]
             for key in mine:
                 if key in theirs and mine[key] != theirs[key]:
                     collisions.setdefault(section, {})
                     collisions[section][key] = "%r ignored, using %r" % (mine[key], theirs[key])
         return collisions
     
     def __contains__(self, key):
         # allow nested contains of the form `"Section.key" in config`
         if '.' in key:
             first, remainder = key.split('.', 1)
             if first not in self:
                 return False
             return remainder in self[first]
         
         return super(Config, self).__contains__(key)
     
     # .has_key is deprecated for dictionaries.
     has_key = __contains__
     
     def _has_section(self, key):
         return _is_section_key(key) and key in self
     
     def copy(self):
         return type(self)(dict.copy(self))
         # copy nested config objects
         for k, v in self.items():
             if isinstance(v, Config):
                 new_config[k] = v.copy()
         return new_config
 
     def __copy__(self):
         return self.copy()
 
     def __deepcopy__(self, memo):
         new_config = type(self)()
         for key, value in self.items():
             if isinstance(value, (Config, LazyConfigValue)):
                 # deep copy config objects
                 value = copy.deepcopy(value, memo)
             elif type(value) in {dict, list, set, tuple}:
                 # shallow copy plain container traits
                 value = copy.copy(value)
             new_config[key] = value
         return new_config
     
     def __getitem__(self, key):
         try:
             return dict.__getitem__(self, key)
         except KeyError:
             if _is_section_key(key):
                 c = Config()
                 dict.__setitem__(self, key, c)
                 return c
             elif not key.startswith('_'):
                 # undefined, create lazy value, used for container methods
                 v = LazyConfigValue()
                 dict.__setitem__(self, key, v)
                 return v
             else:
                 raise KeyError
 
     def __setitem__(self, key, value):
         if _is_section_key(key):
             if not isinstance(value, Config):
                 raise ValueError('values whose keys begin with an uppercase '
                                  'char must be Config instances: %r, %r' % (key, value))
         dict.__setitem__(self, key, value)
 
     def __getattr__(self, key):
         if key.startswith('__'):
             return dict.__getattr__(self, key)
         try:
             return self.__getitem__(key)
         except KeyError as e:
             raise AttributeError(e)
 
     def __setattr__(self, key, value):
         if key.startswith('__'):
             return dict.__setattr__(self, key, value)
         try:
             self.__setitem__(key, value)
         except KeyError as e:
             raise AttributeError(e)
 
     def __delattr__(self, key):
         if key.startswith('__'):
             return dict.__delattr__(self, key)
         try:
             dict.__delitem__(self, key)
         except KeyError as e:
             raise AttributeError(e)
 
 
 #-----------------------------------------------------------------------------
 # Config loading classes
 #-----------------------------------------------------------------------------
 
 
 class ConfigLoader(object):
     """A object for loading configurations from just about anywhere.
 
     The resulting configuration is packaged as a :class:`Config`.
 
     Notes
     -----
     A :class:`ConfigLoader` does one thing: load a config from a source
     (file, command line arguments) and returns the data as a :class:`Config` object.
     There are lots of things that :class:`ConfigLoader` does not do.  It does
     not implement complex logic for finding config files.  It does not handle
     default values or merge multiple configs.  These things need to be
     handled elsewhere.
     """
 
     def _log_default(self):
         from IPython.utils.log import get_logger
         return get_logger()
 
     def __init__(self, log=None):
         """A base class for config loaders.
 
         log : instance of :class:`logging.Logger` to use.
               By default loger of :meth:`IPython.config.application.Application.instance()`
               will be used
 
         Examples
         --------
 
         >>> cl = ConfigLoader()
         >>> config = cl.load_config()
         >>> config
         {}
         """
         self.clear()
         if log is None:
             self.log = self._log_default()
             self.log.debug('Using default logger')
         else:
             self.log = log
 
     def clear(self):
         self.config = Config()
 
     def load_config(self):
         """Load a config from somewhere, return a :class:`Config` instance.
 
         Usually, this will cause self.config to be set and then returned.
         However, in most cases, :meth:`ConfigLoader.clear` should be called
         to erase any previous state.
         """
         self.clear()
         return self.config
 
 
 class FileConfigLoader(ConfigLoader):
     """A base class for file based configurations.
 
     As we add more file based config loaders, the common logic should go
     here.
     """
 
     def __init__(self, filename, path=None, **kw):
         """Build a config loader for a filename and path.
 
         Parameters
         ----------
         filename : str
             The file name of the config file.
         path : str, list, tuple
             The path to search for the config file on, or a sequence of
             paths to try in order.
         """
         super(FileConfigLoader, self).__init__(**kw)
         self.filename = filename
         self.path = path
         self.full_filename = ''
 
     def _find_file(self):
         """Try to find the file by searching the paths."""
         self.full_filename = filefind(self.filename, self.path)
 
 class JSONFileConfigLoader(FileConfigLoader):
     """A JSON file loader for config"""
 
     def load_config(self):
         """Load the config from a file and return it as a Config object."""
         self.clear()
         try:
             self._find_file()
         except IOError as e:
             raise ConfigFileNotFound(str(e))
         dct = self._read_file_as_dict()
         self.config = self._convert_to_config(dct)
         return self.config
 
     def _read_file_as_dict(self):
         with open(self.full_filename) as f:
             return json.load(f)
 
     def _convert_to_config(self, dictionary):
         if 'version' in dictionary:
             version = dictionary.pop('version')
         else:
             version = 1
             self.log.warn("Unrecognized JSON config file version, assuming version {}".format(version))
 
         if version == 1:
             return Config(dictionary)
         else:
             raise ValueError('Unknown version of JSON config file: {version}'.format(version=version))
 
 
 class PyFileConfigLoader(FileConfigLoader):
     """A config loader for pure python files.
 
     This is responsible for locating a Python config file by filename and
     path, then executing it to construct a Config object.
     """
 
     def load_config(self):
         """Load the config from a file and return it as a Config object."""
         self.clear()
         try:
             self._find_file()
         except IOError as e:
             raise ConfigFileNotFound(str(e))
         self._read_file_as_dict()
         return self.config
-
-
+    
+    def load_subconfig(self, fname, path=None):
+        """Injected into config file namespace as load_subconfig"""
+        if path is None:
+            path = self.path
+        
+        loader = self.__class__(fname, path)
+        try:
+            sub_config = loader.load_config()
+        except ConfigFileNotFound:
+            # Pass silently if the sub config is not there,
+            # treat it as an empty config file.
+            pass
+        else:
+            self.config.merge(sub_config)
+    
     def _read_file_as_dict(self):
         """Load the config file into self.config, with recursive loading."""
-        # This closure is made available in the namespace that is used
-        # to exec the config file.  It allows users to call
-        # load_subconfig('myconfig.py') to load config files recursively.
-        # It needs to be a closure because it has references to self.path
-        # and self.config.  The sub-config is loaded with the same path
-        # as the parent, but it uses an empty config which is then merged
-        # with the parents.
-
-        # If a profile is specified, the config file will be loaded
-        # from that profile
-
-        def load_subconfig(fname, profile=None):
-            # import here to prevent circular imports
-            from IPython.core.profiledir import ProfileDir, ProfileDirError
-            if profile is not None:
-                try:
-                    profile_dir = ProfileDir.find_profile_dir_by_name(
-                            get_ipython_dir(),
-                            profile,
-                    )
-                except ProfileDirError:
-                    return
-                path = profile_dir.location
-            else:
-                path = self.path
-            loader = PyFileConfigLoader(fname, path)
-            try:
-                sub_config = loader.load_config()
-            except ConfigFileNotFound:
-                # Pass silently if the sub config is not there. This happens
-                # when a user s using a profile, but not the default config.
-                pass
-            else:
-                self.config.merge(sub_config)
-
-        # Again, this needs to be a closure and should be used in config
-        # files to get the config being loaded.
         def get_config():
             return self.config
-
+        
         namespace = dict(
-            load_subconfig=load_subconfig,
+            load_subconfig=self.load_subconfig,
             get_config=get_config,
             __file__=self.full_filename,
         )
         fs_encoding = sys.getfilesystemencoding() or 'ascii'
         conf_filename = self.full_filename.encode(fs_encoding)
         py3compat.execfile(conf_filename, namespace)
 
 
 class CommandLineConfigLoader(ConfigLoader):
     """A config loader for command line arguments.
 
     As we add more command line based loaders, the common logic should go
     here.
     """
 
     def _exec_config_str(self, lhs, rhs):
         """execute self.config.<lhs> = <rhs>
         
         * expands ~ with expanduser
         * tries to assign with literal_eval, otherwise assigns with just the string,
           allowing `--C.a=foobar` and `--C.a="foobar"` to be equivalent.  *Not*
           equivalent are `--C.a=4` and `--C.a='4'`.
         """
         rhs = os.path.expanduser(rhs)
         try:
             # Try to see if regular Python syntax will work. This
             # won't handle strings as the quote marks are removed
             # by the system shell.
             value = literal_eval(rhs)
         except (NameError, SyntaxError, ValueError):
             # This case happens if the rhs is a string.
             value = rhs
 
         exec(u'self.config.%s = value' % lhs)
 
     def _load_flag(self, cfg):
         """update self.config from a flag, which can be a dict or Config"""
         if isinstance(cfg, (dict, Config)):
             # don't clobber whole config sections, update
             # each section from config:
             for sec,c in iteritems(cfg):
                 self.config[sec].update(c)
         else:
             raise TypeError("Invalid flag: %r" % cfg)
 
 # raw --identifier=value pattern
 # but *also* accept '-' as wordsep, for aliases
 # accepts:  --foo=a
 #           --Class.trait=value
 #           --alias-name=value
 # rejects:  -foo=value
 #           --foo
 #           --Class.trait
 kv_pattern = re.compile(r'\-\-[A-Za-z][\w\-]*(\.[\w\-]+)*\=.*')
 
 # just flags, no assignments, with two *or one* leading '-'
 # accepts:  --foo
 #           -foo-bar-again
 # rejects:  --anything=anything
 #           --two.word
 
 flag_pattern = re.compile(r'\-\-?\w+[\-\w]*$')
 
 class KeyValueConfigLoader(CommandLineConfigLoader):
     """A config loader that loads key value pairs from the command line.
 
     This allows command line options to be gives in the following form::
 
         ipython --profile="foo" --InteractiveShell.autocall=False
     """
 
     def __init__(self, argv=None, aliases=None, flags=None, **kw):
         """Create a key value pair config loader.
 
         Parameters
         ----------
         argv : list
             A list that has the form of sys.argv[1:] which has unicode
             elements of the form u"key=value". If this is None (default),
             then sys.argv[1:] will be used.
         aliases : dict
             A dict of aliases for configurable traits.
             Keys are the short aliases, Values are the resolved trait.
             Of the form: `{'alias' : 'Configurable.trait'}`
         flags : dict
             A dict of flags, keyed by str name. Vaues can be Config objects,
             dicts, or "key=value" strings.  If Config or dict, when the flag
             is triggered, The flag is loaded as `self.config.update(m)`.
 
         Returns
         -------
         config : Config
             The resulting Config object.
 
         Examples
         --------
 
             >>> from IPython.config.loader import KeyValueConfigLoader
             >>> cl = KeyValueConfigLoader()
             >>> d = cl.load_config(["--A.name='brian'","--B.number=0"])
             >>> sorted(d.items())
             [('A', {'name': 'brian'}), ('B', {'number': 0})]
         """
         super(KeyValueConfigLoader, self).__init__(**kw)
         if argv is None:
             argv = sys.argv[1:]
         self.argv = argv
         self.aliases = aliases or {}
         self.flags = flags or {}
 
 
     def clear(self):
         super(KeyValueConfigLoader, self).clear()
         self.extra_args = []
 
 
     def _decode_argv(self, argv, enc=None):
         """decode argv if bytes, using stdin.encoding, falling back on default enc"""
         uargv = []
         if enc is None:
             enc = DEFAULT_ENCODING
         for arg in argv:
             if not isinstance(arg, unicode_type):
                 # only decode if not already decoded
                 arg = arg.decode(enc)
             uargv.append(arg)
         return uargv
 
 
     def load_config(self, argv=None, aliases=None, flags=None):
         """Parse the configuration and generate the Config object.
 
         After loading, any arguments that are not key-value or
         flags will be stored in self.extra_args - a list of
         unparsed command-line arguments.  This is used for
         arguments such as input files or subcommands.
 
         Parameters
         ----------
         argv : list, optional
             A list that has the form of sys.argv[1:] which has unicode
             elements of the form u"key=value". If this is None (default),
             then self.argv will be used.
         aliases : dict
             A dict of aliases for configurable traits.
             Keys are the short aliases, Values are the resolved trait.
             Of the form: `{'alias' : 'Configurable.trait'}`
         flags : dict
             A dict of flags, keyed by str name. Values can be Config objects
             or dicts.  When the flag is triggered, The config is loaded as
             `self.config.update(cfg)`.
         """
         self.clear()
         if argv is None:
             argv = self.argv
         if aliases is None:
             aliases = self.aliases
         if flags is None:
             flags = self.flags
 
         # ensure argv is a list of unicode strings:
         uargv = self._decode_argv(argv)
         for idx,raw in enumerate(uargv):
             # strip leading '-'
             item = raw.lstrip('-')
 
             if raw == '--':
                 # don't parse arguments after '--'
                 # this is useful for relaying arguments to scripts, e.g.
                 # ipython -i foo.py --matplotlib=qt -- args after '--' go-to-foo.py
                 self.extra_args.extend(uargv[idx+1:])
                 break
 
             if kv_pattern.match(raw):
                 lhs,rhs = item.split('=',1)
                 # Substitute longnames for aliases.
                 if lhs in aliases:
                     lhs = aliases[lhs]
                 if '.' not in lhs:
                     # probably a mistyped alias, but not technically illegal
                     self.log.warn("Unrecognized alias: '%s', it will probably have no effect.", raw)
                 try:
                     self._exec_config_str(lhs, rhs)
                 except Exception:
                     raise ArgumentError("Invalid argument: '%s'" % raw)
 
             elif flag_pattern.match(raw):
                 if item in flags:
                     cfg,help = flags[item]
                     self._load_flag(cfg)
                 else:
                     raise ArgumentError("Unrecognized flag: '%s'"%raw)
             elif raw.startswith('-'):
                 kv = '--'+item
                 if kv_pattern.match(kv):
                     raise ArgumentError("Invalid argument: '%s', did you mean '%s'?"%(raw, kv))
                 else:
                     raise ArgumentError("Invalid argument: '%s'"%raw)
             else:
                 # keep all args that aren't valid in a list,
                 # in case our parent knows what to do with them.
                 self.extra_args.append(item)
         return self.config
 
 class ArgParseConfigLoader(CommandLineConfigLoader):
     """A loader that uses the argparse module to load from the command line."""
 
     def __init__(self, argv=None, aliases=None, flags=None, log=None,  *parser_args, **parser_kw):
         """Create a config loader for use with argparse.
 
         Parameters
         ----------
 
         argv : optional, list
           If given, used to read command-line arguments from, otherwise
           sys.argv[1:] is used.
 
         parser_args : tuple
           A tuple of positional arguments that will be passed to the
           constructor of :class:`argparse.ArgumentParser`.
 
         parser_kw : dict
           A tuple of keyword arguments that will be passed to the
           constructor of :class:`argparse.ArgumentParser`.
 
         Returns
         -------
         config : Config
             The resulting Config object.
         """
         super(CommandLineConfigLoader, self).__init__(log=log)
         self.clear()
         if argv is None:
             argv = sys.argv[1:]
         self.argv = argv
         self.aliases = aliases or {}
         self.flags = flags or {}
 
         self.parser_args = parser_args
         self.version = parser_kw.pop("version", None)
         kwargs = dict(argument_default=argparse.SUPPRESS)
         kwargs.update(parser_kw)
         self.parser_kw = kwargs
 
     def load_config(self, argv=None, aliases=None, flags=None):
         """Parse command line arguments and return as a Config object.
 
         Parameters
         ----------
 
         args : optional, list
           If given, a list with the structure of sys.argv[1:] to parse
           arguments from. If not given, the instance's self.argv attribute
           (given at construction time) is used."""
         self.clear()
         if argv is None:
             argv = self.argv
         if aliases is None:
             aliases = self.aliases
         if flags is None:
             flags = self.flags
         self._create_parser(aliases, flags)
         self._parse_args(argv)
         self._convert_to_config()
         return self.config
 
     def get_extra_args(self):
         if hasattr(self, 'extra_args'):
             return self.extra_args
         else:
             return []
 
     def _create_parser(self, aliases=None, flags=None):
         self.parser = ArgumentParser(*self.parser_args, **self.parser_kw)
         self._add_arguments(aliases, flags)
 
     def _add_arguments(self, aliases=None, flags=None):
         raise NotImplementedError("subclasses must implement _add_arguments")
 
     def _parse_args(self, args):
         """self.parser->self.parsed_data"""
         # decode sys.argv to support unicode command-line options
         enc = DEFAULT_ENCODING
         uargs = [py3compat.cast_unicode(a, enc) for a in args]
         self.parsed_data, self.extra_args = self.parser.parse_known_args(uargs)
 
     def _convert_to_config(self):
         """self.parsed_data->self.config"""
         for k, v in iteritems(vars(self.parsed_data)):
             exec("self.config.%s = v"%k, locals(), globals())
 
 class KVArgParseConfigLoader(ArgParseConfigLoader):
     """A config loader that loads aliases and flags with argparse,
     but will use KVLoader for the rest.  This allows better parsing
     of common args, such as `ipython -c 'print 5'`, but still gets
     arbitrary config with `ipython --InteractiveShell.use_readline=False`"""
 
     def _add_arguments(self, aliases=None, flags=None):
         self.alias_flags = {}
         # print aliases, flags
         if aliases is None:
             aliases = self.aliases
         if flags is None:
             flags = self.flags
         paa = self.parser.add_argument
         for key,value in iteritems(aliases):
             if key in flags:
                 # flags
                 nargs = '?'
             else:
                 nargs = None
             if len(key) is 1:
                 paa('-'+key, '--'+key, type=unicode_type, dest=value, nargs=nargs)
             else:
                 paa('--'+key, type=unicode_type, dest=value, nargs=nargs)
         for key, (value, help) in iteritems(flags):
             if key in self.aliases:
                 #
                 self.alias_flags[self.aliases[key]] = value
                 continue
             if len(key) is 1:
                 paa('-'+key, '--'+key, action='append_const', dest='_flags', const=value)
             else:
                 paa('--'+key, action='append_const', dest='_flags', const=value)
 
     def _convert_to_config(self):
         """self.parsed_data->self.config, parse unrecognized extra args via KVLoader."""
         # remove subconfigs list from namespace before transforming the Namespace
         if '_flags' in self.parsed_data:
             subcs = self.parsed_data._flags
             del self.parsed_data._flags
         else:
             subcs = []
 
         for k, v in iteritems(vars(self.parsed_data)):
             if v is None:
                 # it was a flag that shares the name of an alias
                 subcs.append(self.alias_flags[k])
             else:
                 # eval the KV assignment
                 self._exec_config_str(k, v)
 
         for subc in subcs:
             self._load_flag(subc)
 
         if self.extra_args:
             sub_parser = KeyValueConfigLoader(log=self.log)
             sub_parser.load_config(self.extra_args)
             self.config.merge(sub_parser.config)
             self.extra_args = sub_parser.extra_args
 
 
 def load_pyconfig_files(config_files, path):
     """Load multiple Python config files, merging each of them in turn.
 
     Parameters
     ==========
     config_files : list of str
         List of config files names to load and merge into the config.
     path : unicode
         The full path to the location of the config files.
     """
     config = Config()
     for cf in config_files:
         loader = PyFileConfigLoader(cf, path=path)
         try:
             next_config = loader.load_config()
         except ConfigFileNotFound:
             pass
         except:
             raise
         else:
             config.merge(next_config)
     return config

IPython/core/application.py

@@ -1,380 +1,396 b''
 # encoding: utf-8
 """
 An application for IPython.
 
 All top-level applications should use the classes in this module for
 handling configuration and creating configurables.
 
 The job of an :class:`Application` is to create the master configuration
 object and then create the configurable objects, passing the config to them.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import atexit
 import glob
 import logging
 import os
 import shutil
 import sys
 
 from IPython.config.application import Application, catch_config_error
-from IPython.config.loader import ConfigFileNotFound
+from IPython.config.loader import ConfigFileNotFound, PyFileConfigLoader
 from IPython.core import release, crashhandler
 from IPython.core.profiledir import ProfileDir, ProfileDirError
 from IPython.utils.path import get_ipython_dir, get_ipython_package_dir, ensure_dir_exists
 from IPython.utils import py3compat
 from IPython.utils.traitlets import List, Unicode, Type, Bool, Dict, Set, Instance
 
 if os.name == 'nt':
     programdata = os.environ.get('PROGRAMDATA', None)
     if programdata:
         SYSTEM_CONFIG_DIRS = [os.path.join(programdata, 'ipython')]
     else:  # PROGRAMDATA is not defined by default on XP.
         SYSTEM_CONFIG_DIRS = []
 else:
     SYSTEM_CONFIG_DIRS = [
         "/usr/local/etc/ipython",
         "/etc/ipython",
     ]
 
 
 # aliases and flags
 
 base_aliases = {
     'profile-dir' : 'ProfileDir.location',
     'profile' : 'BaseIPythonApplication.profile',
     'ipython-dir' : 'BaseIPythonApplication.ipython_dir',
     'log-level' : 'Application.log_level',
     'config' : 'BaseIPythonApplication.extra_config_file',
 }
 
 base_flags = dict(
     debug = ({'Application' : {'log_level' : logging.DEBUG}},
             "set log level to logging.DEBUG (maximize logging output)"),
     quiet = ({'Application' : {'log_level' : logging.CRITICAL}},
             "set log level to logging.CRITICAL (minimize logging output)"),
     init = ({'BaseIPythonApplication' : {
                     'copy_config_files' : True,
                     'auto_create' : True}
             }, """Initialize profile with default config files.  This is equivalent
             to running `ipython profile create <profile>` prior to startup.
             """)
 )
 
+class ProfileAwareConfigLoader(PyFileConfigLoader):
+    """A Python file config loader that is aware of IPython profiles."""
+    def load_subconfig(self, fname, path=None, profile=None):
+        if profile is not None:
+            try:
+                profile_dir = ProfileDir.find_profile_dir_by_name(
+                        get_ipython_dir(),
+                        profile,
+                )
+            except ProfileDirError:
+                return
+            path = profile_dir.location
+        return super(ProfileAwareConfigLoader, self).load_subconfig(fname, path=path)
 
 class BaseIPythonApplication(Application):
 
     name = Unicode(u'ipython')
     description = Unicode(u'IPython: an enhanced interactive Python shell.')
     version = Unicode(release.version)
 
     aliases = Dict(base_aliases)
     flags = Dict(base_flags)
     classes = List([ProfileDir])
+    
+    # enable `load_subconfig('cfg.py', profile='name')`
+    python_config_loader_class = ProfileAwareConfigLoader
 
     # Track whether the config_file has changed,
     # because some logic happens only if we aren't using the default.
     config_file_specified = Set()
 
     config_file_name = Unicode()
     def _config_file_name_default(self):
         return self.name.replace('-','_') + u'_config.py'
     def _config_file_name_changed(self, name, old, new):
         if new != old:
             self.config_file_specified.add(new)
 
     # The directory that contains IPython's builtin profiles.
     builtin_profile_dir = Unicode(
         os.path.join(get_ipython_package_dir(), u'config', u'profile', u'default')
     )
     
     config_file_paths = List(Unicode)
     def _config_file_paths_default(self):
         return [py3compat.getcwd()]
 
     extra_config_file = Unicode(config=True,
     help="""Path to an extra config file to load.
     
     If specified, load this config file in addition to any other IPython config.
     """)
     def _extra_config_file_changed(self, name, old, new):
         try:
             self.config_files.remove(old)
         except ValueError:
             pass
         self.config_file_specified.add(new)
         self.config_files.append(new)
 
     profile = Unicode(u'default', config=True,
         help="""The IPython profile to use."""
     )
 
     def _profile_changed(self, name, old, new):
         self.builtin_profile_dir = os.path.join(
                 get_ipython_package_dir(), u'config', u'profile', new
         )
 
     ipython_dir = Unicode(config=True,
         help="""
         The name of the IPython directory. This directory is used for logging
         configuration (through profiles), history storage, etc. The default
         is usually $HOME/.ipython. This option can also be specified through
         the environment variable IPYTHONDIR.
         """
     )
     def _ipython_dir_default(self):
         d = get_ipython_dir()
         self._ipython_dir_changed('ipython_dir', d, d)
         return d
     
     _in_init_profile_dir = False
     profile_dir = Instance(ProfileDir)
     def _profile_dir_default(self):
         # avoid recursion
         if self._in_init_profile_dir:
             return
         # profile_dir requested early, force initialization
         self.init_profile_dir()
         return self.profile_dir
 
     overwrite = Bool(False, config=True,
         help="""Whether to overwrite existing config files when copying""")
     auto_create = Bool(False, config=True,
         help="""Whether to create profile dir if it doesn't exist""")
 
     config_files = List(Unicode)
     def _config_files_default(self):
         return [self.config_file_name]
 
     copy_config_files = Bool(False, config=True,
         help="""Whether to install the default config files into the profile dir.
         If a new profile is being created, and IPython contains config files for that
         profile, then they will be staged into the new directory.  Otherwise,
         default config files will be automatically generated.
         """)
     
     verbose_crash = Bool(False, config=True,
         help="""Create a massive crash report when IPython encounters what may be an
         internal error.  The default is to append a short message to the
         usual traceback""")
 
     # The class to use as the crash handler.
     crash_handler_class = Type(crashhandler.CrashHandler)
 
     @catch_config_error
     def __init__(self, **kwargs):
         super(BaseIPythonApplication, self).__init__(**kwargs)
         # ensure current working directory exists
         try:
             directory = py3compat.getcwd()
         except:
             # exit if cwd doesn't exist
             self.log.error("Current working directory doesn't exist.")
             self.exit(1)
 
     #-------------------------------------------------------------------------
     # Various stages of Application creation
     #-------------------------------------------------------------------------
 
     def init_crash_handler(self):
         """Create a crash handler, typically setting sys.excepthook to it."""
         self.crash_handler = self.crash_handler_class(self)
         sys.excepthook = self.excepthook
         def unset_crashhandler():
             sys.excepthook = sys.__excepthook__
         atexit.register(unset_crashhandler)
     
     def excepthook(self, etype, evalue, tb):
         """this is sys.excepthook after init_crashhandler
         
         set self.verbose_crash=True to use our full crashhandler, instead of
         a regular traceback with a short message (crash_handler_lite)
         """
         
         if self.verbose_crash:
             return self.crash_handler(etype, evalue, tb)
         else:
             return crashhandler.crash_handler_lite(etype, evalue, tb)
     
     def _ipython_dir_changed(self, name, old, new):
         if old is not None:
             str_old = py3compat.cast_bytes_py2(os.path.abspath(old),
                 sys.getfilesystemencoding()
             )
             if str_old in sys.path:
                 sys.path.remove(str_old)
         str_path = py3compat.cast_bytes_py2(os.path.abspath(new),
             sys.getfilesystemencoding()
         )
         sys.path.append(str_path)
         ensure_dir_exists(new)
         readme = os.path.join(new, 'README')
         readme_src = os.path.join(get_ipython_package_dir(), u'config', u'profile', 'README')
         if not os.path.exists(readme) and os.path.exists(readme_src):
             shutil.copy(readme_src, readme)
         for d in ('extensions', 'nbextensions'):
             path = os.path.join(new, d)
             try:
                 ensure_dir_exists(path)
             except OSError:
                 # this will not be EEXIST
                 self.log.error("couldn't create path %s: %s", path, e)
         self.log.debug("IPYTHONDIR set to: %s" % new)
 
     def load_config_file(self, suppress_errors=True):
         """Load the config file.
 
         By default, errors in loading config are handled, and a warning
         printed on screen. For testing, the suppress_errors option is set
         to False, so errors will make tests fail.
         """
         self.log.debug("Searching path %s for config files", self.config_file_paths)
         base_config = 'ipython_config.py'
         self.log.debug("Attempting to load config file: %s" %
                        base_config)
         try:
             Application.load_config_file(
                 self,
                 base_config,
                 path=self.config_file_paths
             )
         except ConfigFileNotFound:
             # ignore errors loading parent
             self.log.debug("Config file %s not found", base_config)
             pass
         
         for config_file_name in self.config_files:
             if not config_file_name or config_file_name == base_config:
                 continue
             self.log.debug("Attempting to load config file: %s" %
                            self.config_file_name)
             try:
                 Application.load_config_file(
                     self,
                     config_file_name,
                     path=self.config_file_paths
                 )
             except ConfigFileNotFound:
                 # Only warn if the default config file was NOT being used.
                 if config_file_name in self.config_file_specified:
                     msg = self.log.warn
                 else:
                     msg = self.log.debug
                 msg("Config file not found, skipping: %s", config_file_name)
             except:
                 # For testing purposes.
                 if not suppress_errors:
                     raise
                 self.log.warn("Error loading config file: %s" %
                               self.config_file_name, exc_info=True)
 
     def init_profile_dir(self):
         """initialize the profile dir"""
         self._in_init_profile_dir = True
         if self.profile_dir is not None:
             # already ran
             return
         if 'ProfileDir.location' not in self.config:
             # location not specified, find by profile name
             try:
                 p = ProfileDir.find_profile_dir_by_name(self.ipython_dir, self.profile, self.config)
             except ProfileDirError:
                 # not found, maybe create it (always create default profile)
                 if self.auto_create or self.profile == 'default':
                     try:
                         p = ProfileDir.create_profile_dir_by_name(self.ipython_dir, self.profile, self.config)
                     except ProfileDirError:
                         self.log.fatal("Could not create profile: %r"%self.profile)
                         self.exit(1)
                     else:
                         self.log.info("Created profile dir: %r"%p.location)
                 else:
                     self.log.fatal("Profile %r not found."%self.profile)
                     self.exit(1)
             else:
                 self.log.debug("Using existing profile dir: %r"%p.location)
         else:
             location = self.config.ProfileDir.location
             # location is fully specified
             try:
                 p = ProfileDir.find_profile_dir(location, self.config)
             except ProfileDirError:
                 # not found, maybe create it
                 if self.auto_create:
                     try:
                         p = ProfileDir.create_profile_dir(location, self.config)
                     except ProfileDirError:
                         self.log.fatal("Could not create profile directory: %r"%location)
                         self.exit(1)
                     else:
                         self.log.debug("Creating new profile dir: %r"%location)
                 else:
                     self.log.fatal("Profile directory %r not found."%location)
                     self.exit(1)
             else:
                 self.log.info("Using existing profile dir: %r"%location)
             # if profile_dir is specified explicitly, set profile name
             dir_name = os.path.basename(p.location)
             if dir_name.startswith('profile_'):
                 self.profile = dir_name[8:]
 
         self.profile_dir = p
         self.config_file_paths.append(p.location)
         self._in_init_profile_dir = False
 
     def init_config_files(self):
         """[optionally] copy default config files into profile dir."""
         self.config_file_paths.extend(SYSTEM_CONFIG_DIRS)
         # copy config files
         path = self.builtin_profile_dir
         if self.copy_config_files:
             src = self.profile
 
             cfg = self.config_file_name
             if path and os.path.exists(os.path.join(path, cfg)):
                 self.log.warn("Staging %r from %s into %r [overwrite=%s]"%(
                         cfg, src, self.profile_dir.location, self.overwrite)
                 )
                 self.profile_dir.copy_config_file(cfg, path=path, overwrite=self.overwrite)
             else:
                 self.stage_default_config_file()
         else:
             # Still stage *bundled* config files, but not generated ones
             # This is necessary for `ipython profile=sympy` to load the profile
             # on the first go
             files = glob.glob(os.path.join(path, '*.py'))
             for fullpath in files:
                 cfg = os.path.basename(fullpath)
                 if self.profile_dir.copy_config_file(cfg, path=path, overwrite=False):
                     # file was copied
                     self.log.warn("Staging bundled %s from %s into %r"%(
                             cfg, self.profile, self.profile_dir.location)
                     )
 
 
     def stage_default_config_file(self):
         """auto generate default config file, and stage it into the profile."""
         s = self.generate_config_file()
         fname = os.path.join(self.profile_dir.location, self.config_file_name)
         if self.overwrite or not os.path.exists(fname):
             self.log.warn("Generating default config file: %r"%(fname))
             with open(fname, 'w') as f:
                 f.write(s)
 
     @catch_config_error
     def initialize(self, argv=None):
         # don't hook up crash handler before parsing command-line
         self.parse_command_line(argv)
         self.init_crash_handler()
         if self.subapp is not None:
             # stop here if subapp is taking over
             return
         cl_config = self.config
         self.init_profile_dir()
         self.init_config_files()
         self.load_config_file()
         # enforce cl-opts override configfile opts:
         self.update_config(cl_config)