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 urljoin

from 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 NotSupported

class 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 = request        self.flags = [] if flags is None else list(flags)

    @property    def meta(self):        try:            return self.request.meta        except AttributeError:            raise AttributeError(                "Response.meta not available, this response "                "is not tied to any request"            )

    def _get_url(self):        return self._url

    def _set_url(self, url):        if isinstance(url, str):            self._url = url        else:            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._body

    def _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.url        elif url is None:            raise ValueError("url can‘t be None")        url = self.urljoin(url)        return Request(url, callback,                       method=method,                       headers=headers,                       body=body,                       cookies=cookies,                       meta=meta,                       encoding=encoding,                       priority=priority,                       dont_filter=dont_filter,                       errback=errback,                       cb_kwargs=cb_kwargs)

原文地址：https://www.cnblogs.com/yinminbo/p/12160241.html