mirror of https://github.com/scrapy/scrapy.git
54 lines
1.6 KiB
Python
54 lines
1.6 KiB
Python
# -*- coding: utf-8 -*-
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from __future__ import absolute_import
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from zope.interface import implementer
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from scrapy.interfaces import ISpiderLoader
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from scrapy.utils.misc import walk_modules
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from scrapy.utils.spider import iter_spider_classes
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@implementer(ISpiderLoader)
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class SpiderLoader(object):
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"""
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SpiderLoader is a class which locates and loads spiders
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in a Scrapy project.
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"""
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def __init__(self, settings):
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self.spider_modules = settings.getlist('SPIDER_MODULES')
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self._spiders = {}
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for name in self.spider_modules:
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for module in walk_modules(name):
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self._load_spiders(module)
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def _load_spiders(self, module):
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for spcls in iter_spider_classes(module):
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self._spiders[spcls.name] = spcls
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@classmethod
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def from_settings(cls, settings):
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return cls(settings)
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def load(self, spider_name):
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"""
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Return the Spider class for the given spider name. If the spider
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name is not found, raise a KeyError.
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"""
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try:
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return self._spiders[spider_name]
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except KeyError:
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raise KeyError("Spider not found: {}".format(spider_name))
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def find_by_request(self, request):
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"""
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Return the list of spider names that can handle the given request.
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"""
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return [name for name, cls in self._spiders.items()
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if cls.handles_request(request)]
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def list(self):
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"""
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Return a list with the names of all spiders available in the project.
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"""
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return list(self._spiders.keys())
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