75 lines
2.3 KiB
Python
75 lines
2.3 KiB
Python
# -*- coding: iso-8859-1 -*-
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import os
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import sys
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def get_modules(folder, importprefix):
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"""Find all valid modules in the plugins directory. A valid module
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must have a .py extension, and is importable.
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@return: all loaded valid modules
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@rtype: iterator of module
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"""
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for filename in get_importable_modules(folder):
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try:
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module = load_module(filename, importprefix)
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if module is not None:
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yield module
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except StandardError, msg:
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print "ERROR: could not load module %s: %s" % (filename, msg)
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def get_importable_modules(folder):
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"""Find all module files in the given folder that end witn '.py' and
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don't start with an underscore.
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@return module filenames
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@rtype: iterator of string
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"""
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for fname in sorted(os.listdir(folder)):
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if fname.endswith('.py') and not fname.startswith('_'):
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yield os.path.join(folder, fname)
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def load_module(filename, importprefix):
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"""Load and return the module given by the filename.
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Other exceptions than ImportError are not catched.
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@return: loaded module or None on import errors
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@rtype: module or None
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"""
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name = os.path.splitext(os.path.basename(filename))[0]
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modulename = "%s%s" % (importprefix, name)
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__import__(modulename)
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return sys.modules[modulename]
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def get_plugins(modules, classobj):
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"""Find all scrapers in all modules.
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@param modules: the modules to search
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@ptype modules: iterator of modules
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@return: found scrapers
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@rytpe: iterator of class objects
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"""
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for module in modules:
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for plugin in get_module_plugins(module, classobj):
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yield plugin
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def get_module_plugins(module, classobj):
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"""Return all subclasses of _BasicScraper in the module.
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If the module defines __all__, only those entries will be searched,
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otherwise all objects not starting with '_' will be searched.
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"""
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try:
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names = module.__all__
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except AttributeError:
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names = [x for x in vars(module) if not x.startswith('_')]
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for name in sorted(names):
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try:
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obj = getattr(module, name)
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except AttributeError:
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continue
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try:
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if issubclass(obj, classobj):
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yield obj
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except TypeError:
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continue
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