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 = 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)
来源：https://www.cnblogs.com/yinminbo/p/12160241.html