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"""A simple configuration system.
Authors
-------
* Brian Granger
* Fernando Perez
* Min RK
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2008-2011 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
import __builtin__
import re
import sys
from IPython.external import argparse
from IPython.utils.path import filefind, get_ipython_dir
from IPython.utils import warn
#-----------------------------------------------------------------------------
# Exceptions
#-----------------------------------------------------------------------------
class ConfigError(Exception):
pass
class ConfigLoaderError(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 Config(dict):
"""An attribute based dict that can do smart merges."""
def __init__(self, *args, **kwds):
dict.__init__(self, *args, **kwds)
# This sets self.__dict__ = self, but it has to be done this way
# because we are also overriding __setattr__.
dict.__setattr__(self, '__dict__', self)
def _merge(self, other):
to_update = {}
for k, v in other.iteritems():
if not self.has_key(k):
to_update[k] = v
else: # I have this key
if isinstance(v, Config):
# Recursively merge common sub Configs
self[k]._merge(v)
else:
# Plain updates for non-Configs
to_update[k] = v
self.update(to_update)
def _is_section_key(self, key):
if key[0].upper()==key[0] and not key.startswith('_'):
return True
else:
return False
def __contains__(self, key):
if self._is_section_key(key):
return True
else:
return super(Config, self).__contains__(key)
# .has_key is deprecated for dictionaries.
has_key = __contains__
def _has_section(self, key):
if self._is_section_key(key):
if super(Config, self).__contains__(key):
return True
return False
def copy(self):
return type(self)(dict.copy(self))
def __copy__(self):
return self.copy()
def __deepcopy__(self, memo):
import copy
return type(self)(copy.deepcopy(self.items()))
def __getitem__(self, key):
# We cannot use directly self._is_section_key, because it triggers
# infinite recursion on top of PyPy. Instead, we manually fish the
# bound method.
is_section_key = self.__class__._is_section_key.__get__(self)
# Because we use this for an exec namespace, we need to delegate
# the lookup of names in __builtin__ to itself. This means
# that you can't have section or attribute names that are
# builtins.
try:
return getattr(__builtin__, key)
except AttributeError:
pass
if is_section_key(key):
try:
return dict.__getitem__(self, key)
except KeyError:
c = Config()
dict.__setitem__(self, key, c)
return c
else:
return dict.__getitem__(self, key)
def __setitem__(self, key, value):
# Don't allow names in __builtin__ to be modified.
if hasattr(__builtin__, key):
raise ConfigError('Config variable names cannot have the same name '
'as a Python builtin: %s' % key)
if self._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))
else:
dict.__setitem__(self, key, value)
def __getattr__(self, key):
try:
return self.__getitem__(key)
except KeyError, e:
raise AttributeError(e)
def __setattr__(self, key, value):
try:
self.__setitem__(key, value)
except KeyError, e:
raise AttributeError(e)
def __delattr__(self, key):
try:
dict.__delitem__(self, key)
except KeyError, 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:`Struct`.
Notes
-----
A :class:`ConfigLoader` does one thing: load a config from a source
(file, command line arguments) and returns the data as a :class:`Struct`.
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 __init__(self):
"""A base class for config loaders.
Examples
--------
>>> cl = ConfigLoader()
>>> config = cl.load_config()
>>> config
{}
"""
self.clear()
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.
"""
pass
class PyFileConfigLoader(FileConfigLoader):
"""A config loader for pure python files.
This calls execfile on a plain python file and looks for attributes
that are all caps. These attribute are added to the config Struct.
"""
def __init__(self, filename, path=None):
"""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(PyFileConfigLoader, self).__init__()
self.filename = filename
self.path = path
self.full_filename = ''
self.data = None
def load_config(self):
"""Load the config from a file and return it as a Struct."""
self.clear()
self._find_file()
self._read_file_as_dict()
self._convert_to_config()
return self.config
def _find_file(self):
"""Try to find the file by searching the paths."""
self.full_filename = filefind(self.filename, self.path)
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 IOError:
# 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, get_config=get_config)
fs_encoding = sys.getfilesystemencoding() or 'ascii'
conf_filename = self.full_filename.encode(fs_encoding)
execfile(conf_filename, namespace)
def _convert_to_config(self):
if self.data is None:
ConfigLoaderError('self.data does not exist')
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):
exec_str = 'self.config.' + lhs + '=' + 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.
exec exec_str in locals(), globals()
except (NameError, SyntaxError):
# This case happens if the rhs is a string but without
# the quote marks. Use repr, to get quote marks, and
# 'u' prefix and see if
# it succeeds. If it still fails, we let it raise.
exec_str = u'self.config.' + lhs + '=' + repr(rhs)
exec exec_str in locals(), globals()
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 cfg.iteritems():
self.config[sec].update(c)
else:
raise ValueError("Invalid flag: '%s'"%raw)
# 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):
"""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()
>>> cl.load_config(["--A.name='brian'","--B.number=0"])
{'A': {'name': 'brian'}, 'B': {'number': 0}}
"""
self.clear()
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 stin.encoding, falling back on default enc"""
uargv = []
if enc is None:
enc = sys.stdin.encoding or sys.getdefaultencoding()
for arg in argv:
if not isinstance(arg, unicode):
# 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)`.
"""
from IPython.config.configurable import Configurable
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 --pylab=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
warn.warn("Unrecognized alias: '%s', it will probably have no effect."%lhs)
self._exec_config_str(lhs, rhs)
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, *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__()
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
uargs = []
for a in args:
if isinstance(a, str):
# don't decode if we already got unicode
a = a.decode(sys.stdin.encoding or
sys.getdefaultencoding())
uargs.append(a)
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 vars(self.parsed_data).iteritems():
exec "self.config.%s = v"%k in 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 _convert_to_config(self):
"""self.parsed_data->self.config"""
for k, v in vars(self.parsed_data).iteritems():
self._exec_config_str(k, v)
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 aliases.iteritems():
if key in flags:
# flags
nargs = '?'
else:
nargs = None
if len(key) is 1:
paa('-'+key, '--'+key, type=str, dest=value, nargs=nargs)
else:
paa('--'+key, type=str, dest=value, nargs=nargs)
for key, (value, help) in flags.iteritems():
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 vars(self.parsed_data).iteritems():
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()
sub_parser.load_config(self.extra_args)
self.config._merge(sub_parser.config)
self.extra_args = sub_parser.extra_args
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