loader.py
200 lines
| 6.1 KiB
| text/x-python
|
PythonLexer
Brian Granger
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r2157 | #!/usr/bin/env python | ||
# encoding: utf-8 | ||||
"""A factory for creating configuration objects. | ||||
""" | ||||
#----------------------------------------------------------------------------- | ||||
# 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 os | ||||
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r2185 | import sys | ||
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r2157 | |||
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r2185 | from IPython.external import argparse | ||
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r2157 | from IPython.utils.ipstruct import Struct | ||
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r2200 | from IPython.utils.genutils import filefind | ||
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r2157 | |||
#----------------------------------------------------------------------------- | ||||
# Code | ||||
#----------------------------------------------------------------------------- | ||||
class ConfigLoaderError(Exception): | ||||
pass | ||||
class ConfigLoader(object): | ||||
"""A object for loading configurations from just about anywhere. | ||||
The resulting configuration is packaged as a :class:`Struct`. | ||||
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r2185 | |||
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. | ||||
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r2157 | """ | ||
def __init__(self): | ||||
"""A base class for config loaders. | ||||
Examples | ||||
-------- | ||||
>>> cl = ConfigLoader() | ||||
>>> config = cl.load_config() | ||||
>>> config | ||||
{} | ||||
""" | ||||
self.clear() | ||||
def clear(self): | ||||
self.config = Struct() | ||||
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): | ||||
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r2185 | """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): | ||||
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r2157 | """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. | ||||
""" | ||||
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r2200 | def __init__(self, filename, path=None): | ||
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r2157 | """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 | ||||
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r2185 | paths to try in order. | ||
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r2157 | """ | ||
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r2185 | super(PyFileConfigLoader, self).__init__() | ||
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r2157 | self.filename = filename | ||
self.path = path | ||||
self.full_filename = '' | ||||
self.data = None | ||||
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r2185 | 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_struct() | ||||
return self.config | ||||
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r2157 | |||
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r2185 | def _find_file(self): | ||
"""Try to find the file by searching the paths.""" | ||||
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r2200 | self.full_filename = filefind(self.filename, self.path) | ||
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r2185 | |||
def _read_file_as_dict(self): | ||||
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r2157 | self.data = {} | ||
execfile(self.full_filename, self.data) | ||||
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r2185 | def _convert_to_struct(self): | ||
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r2157 | if self.data is None: | ||
ConfigLoaderError('self.data does not exist') | ||||
for k, v in self.data.iteritems(): | ||||
if k == k.upper(): | ||||
self.config[k] = v | ||||
class CommandLineConfigLoader(ConfigLoader): | ||||
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r2185 | """A config loader for command line arguments. | ||
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r2157 | |||
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r2185 | As we add more command line based loaders, the common logic should go | ||
here. | ||||
""" | ||||
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r2157 | |||
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r2185 | class NoDefault(object): pass | ||
NoDefault = NoDefault() | ||||
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r2157 | |||
class ArgParseConfigLoader(CommandLineConfigLoader): | ||||
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r2185 | |||
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r2157 | # arguments = [(('-f','--file'),dict(type=str,dest='file'))] | ||
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r2198 | arguments = () | ||
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r2157 | |||
def __init__(self, *args, **kw): | ||||
"""Create a config loader for use with argparse. | ||||
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r2185 | |||
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r2157 | The args and kwargs arguments here are passed onto the constructor | ||
of :class:`argparse.ArgumentParser`. | ||||
""" | ||||
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r2185 | super(CommandLineConfigLoader, self).__init__() | ||
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r2157 | self.args = args | ||
self.kw = kw | ||||
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r2185 | def load_config(self, args=None): | ||
"""Parse command line arguments and return as a Struct.""" | ||||
self._create_parser() | ||||
self._parse_args(args) | ||||
self._convert_to_struct() | ||||
return self.config | ||||
def _create_parser(self): | ||||
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r2157 | self.parser = argparse.ArgumentParser(*self.args, **self.kw) | ||
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r2185 | self._add_arguments() | ||
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r2200 | self._add_other_arguments() | ||
def _add_other_arguments(): | ||||
pass | ||||
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r2157 | |||
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r2185 | def _add_arguments(self): | ||
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r2157 | for argument in self.arguments: | ||
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r2186 | if not argument[1].has_key('default'): | ||
argument[1]['default'] = NoDefault | ||||
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r2157 | self.parser.add_argument(*argument[0],**argument[1]) | ||
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r2185 | def _parse_args(self, args=None): | ||
"""self.parser->self.parsed_data""" | ||||
if args is None: | ||||
self.parsed_data = self.parser.parse_args() | ||||
else: | ||||
self.parsed_data = self.parser.parse_args(args) | ||||
def _convert_to_struct(self): | ||||
"""self.parsed_data->self.config""" | ||||
self.config = Struct() | ||||
for k, v in vars(self.parsed_data).items(): | ||||
if v is not NoDefault: | ||||
setattr(self.config, k, v) | ||||
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r2200 | class IPythonArgParseConfigLoader(ArgParseConfigLoader): | ||
def _add_other_arguments(self): | ||||
self.parser.add_argument('--ipythondir',dest='IPYTHONDIR',type=str, | ||||
help='set to override default location of IPYTHONDIR', | ||||
default=NoDefault) | ||||
self.parser.add_argument('-p','--p',dest='PROFILE_NAME',type=str, | ||||
help='the string name of the ipython profile to be used', | ||||
default=None) | ||||
self.parser.add_argument('--debug',dest="DEBUG",action='store_true', | ||||
help='debug the application startup process', | ||||
default=NoDefault) | ||||