|
|
# coding: utf-8
|
|
|
"""A simple configuration system.
|
|
|
|
|
|
Authors
|
|
|
-------
|
|
|
* Brian Granger
|
|
|
* Fernando Perez
|
|
|
"""
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# 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 __builtin__
|
|
|
import os
|
|
|
import sys
|
|
|
|
|
|
from IPython.external import argparse
|
|
|
from IPython.utils.genutils import filefind
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Exceptions
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
class ConfigError(Exception):
|
|
|
pass
|
|
|
|
|
|
|
|
|
class ConfigLoaderError(ConfigError):
|
|
|
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.items():
|
|
|
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 has_key(self, key):
|
|
|
if self._is_section_key(key):
|
|
|
return True
|
|
|
else:
|
|
|
return dict.has_key(self, key)
|
|
|
|
|
|
def _has_section(self, key):
|
|
|
if self._is_section_key(key):
|
|
|
if dict.has_key(self, 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):
|
|
|
# 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 self._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 Struct.
|
|
|
|
|
|
Usually, this will cause self.config to be set and then returned.
|
|
|
"""
|
|
|
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._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. This 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.
|
|
|
def load_subconfig(fname):
|
|
|
loader = PyFileConfigLoader(fname, self.path)
|
|
|
try:
|
|
|
sub_config = loader.load_config()
|
|
|
except IOError:
|
|
|
# Pass silently if the sub config is not there. This happens
|
|
|
# when a user us 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)
|
|
|
execfile(self.full_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.
|
|
|
"""
|
|
|
|
|
|
|
|
|
class NoConfigDefault(object): pass
|
|
|
NoConfigDefault = NoConfigDefault()
|
|
|
|
|
|
|
|
|
class ArgParseConfigLoader(CommandLineConfigLoader):
|
|
|
|
|
|
def __init__(self, argv=None, arguments=(), *args, **kw):
|
|
|
"""Create a config loader for use with argparse.
|
|
|
|
|
|
With the exception of ``argv`` and ``arguments``, other args and kwargs
|
|
|
arguments here are passed onto the constructor of
|
|
|
:class:`argparse.ArgumentParser`.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
|
|
|
argv : optional, list
|
|
|
If given, used to read command-line arguments from, otherwise
|
|
|
sys.argv[1:] is used.
|
|
|
|
|
|
arguments : optional, tuple
|
|
|
Description of valid command-line arguments, to be called in sequence
|
|
|
with parser.add_argument() to configure the parser.
|
|
|
"""
|
|
|
super(CommandLineConfigLoader, self).__init__()
|
|
|
if argv == None:
|
|
|
argv = sys.argv[1:]
|
|
|
self.argv = argv
|
|
|
self.arguments = arguments
|
|
|
self.args = args
|
|
|
self.kw = kw
|
|
|
|
|
|
def load_config(self, args=None):
|
|
|
"""Parse command line arguments and return as a Struct.
|
|
|
|
|
|
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."""
|
|
|
|
|
|
if args is None:
|
|
|
args = self.argv
|
|
|
self._create_parser()
|
|
|
self._parse_args(args)
|
|
|
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):
|
|
|
self.parser = ArgumentParser(*self.args, **self.kw)
|
|
|
self._add_arguments()
|
|
|
self._add_other_arguments()
|
|
|
|
|
|
def _add_other_arguments(self):
|
|
|
pass
|
|
|
|
|
|
def _add_arguments(self):
|
|
|
for argument in self.arguments:
|
|
|
argument[1].setdefault('default', NoConfigDefault)
|
|
|
self.parser.add_argument(*argument[0],**argument[1])
|
|
|
|
|
|
def _parse_args(self, args):
|
|
|
"""self.parser->self.parsed_data"""
|
|
|
self.parsed_data, self.extra_args = self.parser.parse_known_args(args)
|
|
|
|
|
|
def _convert_to_config(self):
|
|
|
"""self.parsed_data->self.config"""
|
|
|
for k, v in vars(self.parsed_data).items():
|
|
|
if v is not NoConfigDefault:
|
|
|
exec_str = 'self.config.' + k + '= v'
|
|
|
exec exec_str in locals(), globals()
|
|
|
|
