Scrapy源码 Request对象
"""This module implements the Request class which is used to represent HTTPrequests in Scrapy.See documentation in docs/topics/request-response.rst"""import sixfrom w3lib.url import safe_url_stringfrom scrapy.http.headers import Headersfrom scrapy.utils.python import to_bytesfrom scrapy.utils.trackref import object_reffrom scrapy.utils.url import escape_ajaxfrom scrapy.http.common import obsolete_setterfrom scrapy.utils.curl import curl_to_request_kwargsclass Request(object_ref): def __init__(self, url, callback=None, method='GET', headers=None, body=None, cookies=None, meta=None, encoding='utf-8', priority=0, dont_filter=False, errback=None, flags=None, cb_kwargs=None): self._encoding = encoding # this one has to be set first self.method = str(method).upper() self._set_url(url) self._set_body(body) assert isinstance(priority, int), "Request priority not an integer: %r" % priority self.priority = priority if callback is not None and not callable(callback): raise TypeError('callback must be a callable, got %s' % type(callback).__name__) if errback is not None and not callable(errback): raise TypeError('errback must be a callable, got %s' % type(errback).__name__) assert callback or not errback, "Cannot use errback without a callback" self.callback = callback self.errback = errback self.cookies = cookies or {} self.headers = Headers(headers or {}, encoding=encoding) self.dont_filter = dont_filter self._meta = dict(meta) if meta else None self._cb_kwargs = dict(cb_kwargs) if cb_kwargs else None self.flags = [] if flags is None else list(flags) @property def cb_kwargs(self): if self._cb_kwargs is None: self._cb_kwargs = {} return self._cb_kwargs @property def meta(self): if self._meta is None: self._meta = {} return self._meta def _get_url(self): return self._url def _set_url(self, url): if not isinstance(url, six.string_types): raise TypeError('Request url must be str or unicode, got %s:' % type(url).__name__) s = safe_url_string(url, self.encoding) self._url = escape_ajax(s) if ':' not in self._url: raise ValueError('Missing scheme in request url: %s' % self._url) 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'' else: self._body = to_bytes(body, self.encoding) body = property(_get_body, obsolete_setter(_set_body, 'body')) @property def encoding(self): return self._encoding def __str__(self): return "<%s %s>" % (self.method, self.url) __repr__ = __str__ def copy(self): """Return a copy of this Request""" return self.replace() def replace(self, *args, **kwargs): """Create a new Request with the same attributes except for those given new values. """ for x in ['url', 'method', 'headers', 'body', 'cookies', 'meta', 'flags', 'encoding', 'priority', 'dont_filter', 'callback', 'errback', 'cb_kwargs']: kwargs.setdefault(x, getattr(self, x)) cls = kwargs.pop('cls', self.__class__) return cls(*args, **kwargs) @classmethod def from_curl(cls, curl_command, ignore_unknown_options=True, **kwargs): """Create a Request object from a string containing a `cURL <https://curl.haxx.se/>`_ command. It populates the HTTP method, the URL, the headers, the cookies and the body. It accepts the same arguments as the :class:`Request` class, taking preference and overriding the values of the same arguments contained in the cURL command. Unrecognized options are ignored by default. To raise an error when finding unknown options call this method by passing ``ignore_unknown_options=False``. .. caution:: Using :meth:`from_curl` from :class:`~scrapy.http.Request` subclasses, such as :class:`~scrapy.http.JSONRequest`, or :class:`~scrapy.http.XmlRpcRequest`, as well as having :ref:`downloader middlewares <topics-downloader-middleware>` and :ref:`spider middlewares <topics-spider-middleware>` enabled, such as :class:`~scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware`, :class:`~scrapy.downloadermiddlewares.useragent.UserAgentMiddleware`, or :class:`~scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware`, may modify the :class:`~scrapy.http.Request` object. """ request_kwargs = curl_to_request_kwargs(curl_command, ignore_unknown_options) request_kwargs.update(kwargs) return cls(**request_kwargs)
来源：https://www.cnblogs.com/yinminbo/p/12159232.html