Scrapy源码 Response对象

Scrapy源码 Response对象

"""This module implements the Response class which is used to represent HTTPresponses in Scrapy.See documentation in docs/topics/request-response.rst"""from six.moves.urllib.parse import urljoinfrom scrapy.http.request import Requestfrom scrapy.http.headers import Headersfrom scrapy.link import Linkfrom scrapy.utils.trackref import object_reffrom scrapy.http.common import obsolete_setterfrom scrapy.exceptions import NotSupportedclass Response(object_ref):def __init__(self, url, status=200, headers=None, body=b‘‘, flags=None, request=None):self.headers = Headers(headers or {})self.status = int(status)self._set_body(body)self._set_url(url)self.request = requestself.flags = [] if flags is None else list(flags)@property    def meta(self):try:return self.request.metaexcept AttributeError:raise AttributeError("Response.meta not available, this response "                "is not tied to any request"            )def _get_url(self):return self._urldef _set_url(self, url):if isinstance(url, str):self._url = urlelse:raise TypeError(‘%s url must be str, got %s:‘ % (type(self).__name__,                type(url).__name__))    url = property(_get_url, obsolete_setter(_set_url, ‘url‘))def _get_body(self):return self._bodydef _set_body(self, body):if body is None:self._body = b‘‘        elif not isinstance(body, bytes):raise TypeError("Response body must be bytes. "                "If you want to pass unicode body use TextResponse "                "or HtmlResponse.")else:self._body = body    body = property(_get_body, obsolete_setter(_set_body, ‘body‘))def __str__(self):return "<%d %s>" % (self.status, self.url)__repr__ = __str__    def copy(self):"""Return a copy of this Response"""        return self.replace()def replace(self, *args, **kwargs):"""Create a new Response with the same attributes except for those        given new values.        """        for x in [‘url‘, ‘status‘, ‘headers‘, ‘body‘, ‘request‘, ‘flags‘]:            kwargs.setdefault(x, getattr(self, x))        cls = kwargs.pop(‘cls‘, self.__class__)return cls(*args, **kwargs)def urljoin(self, url):"""Join this Response‘s url with a possible relative url to form an        absolute interpretation of the latter."""        return urljoin(self.url, url)@property    def text(self):"""For subclasses of TextResponse, this will return the body        as text (unicode object in Python 2 and str in Python 3)        """        raise AttributeError("Response content isn‘t text")def css(self, *a, **kw):"""Shortcut method implemented only by responses whose content        is text (subclasses of TextResponse).        """        raise NotSupported("Response content isn‘t text")def xpath(self, *a, **kw):"""Shortcut method implemented only by responses whose content        is text (subclasses of TextResponse).        """        raise NotSupported("Response content isn‘t text")def follow(self, url, callback=None, method=‘GET‘, headers=None, body=None,               cookies=None, meta=None, encoding=‘utf-8‘, priority=0,               dont_filter=False, errback=None, cb_kwargs=None):# type: (...) -> Request        """        Return a :class:`~.Request` instance to follow a link ``url``.        It accepts the same arguments as ``Request.__init__`` method,        but ``url`` can be a relative URL or a ``scrapy.link.Link`` object,        not only an absolute URL.                :class:`~.TextResponse` provides a :meth:`~.TextResponse.follow`         method which supports selectors in addition to absolute/relative URLs        and Link objects.        """        if isinstance(url, Link):            url = url.urlelif url