zoukankan      html  css  js  c++  java
  • 20.6. urllib2 — extensible library for opening URLs — Python v2.7.3 documentation

    20.6. urllib2 — extensible library for opening URLs — Python v2.7.3 documentation

    class urllib2.Request(url[, data][, headers][, origin_req_host][, unverifiable])

    This class is an abstraction of a URL request.

    url should be a string containing a valid URL.

    data may be a string specifying additional data to send to the server, or
    None if no such data is needed. Currently HTTP requests are the only ones
    that use data; the HTTP request will be a POST instead of a GET when the
    data parameter is provided. data should be a buffer in the standard
    application/x-www-form-urlencoded format. The
    urllib.urlencode() function takes a mapping or sequence of 2-tuples and
    returns a string in this format.

    headers should be a dictionary, and will be treated as if add_header()
    was called with each key and value as arguments. This is often used to “spoof”
    the User-Agent header, which is used by a browser to identify itself –
    some HTTP servers only allow requests coming from common browsers as opposed
    to scripts. For example, Mozilla Firefox may identify itself as "Mozilla/5.0
    (X11; U; Linux i686) Gecko/20071127 Firefox/2.0.0.11"
    , while urllib2‘s
    default user agent string is "Python-urllib/2.6" (on Python 2.6).

    The final two arguments are only of interest for correct handling of third-party
    HTTP cookies:

    origin_req_host should be the request-host of the origin transaction, as
    defined by RFC 2965. It defaults to cookielib.request_host(self). This
    is the host name or IP address of the original request that was initiated by the
    user. For example, if the request is for an image in an HTML document, this
    should be the request-host of the request for the page containing the image.

    unverifiable should indicate whether the request is unverifiable, as defined
    by RFC 2965. It defaults to False. An unverifiable request is one whose URL
    the user did not have the option to approve. For example, if the request is for
    an image in an HTML document, and the user had no option to approve the
    automatic fetching of the image, this should be true.

    class urllib2.OpenerDirector

    The OpenerDirector class opens URLs via BaseHandlers chained
    together. It manages the chaining of handlers, and recovery from errors.

    class urllib2.BaseHandler

    This is the base class for all registered handlers — and handles only the
    simple mechanics of registration.

    class urllib2.HTTPDefaultErrorHandler

    A class which defines a default handler for HTTP error responses; all responses
    are turned into HTTPError exceptions.

    class urllib2.HTTPRedirectHandler

    A class to handle redirections.

    class urllib2.HTTPCookieProcessor([cookiejar])

    A class to handle HTTP Cookies.

    class urllib2.ProxyHandler([proxies])

    Cause requests to go through a proxy. If proxies is given, it must be a
    dictionary mapping protocol names to URLs of proxies. The default is to read
    the list of proxies from the environment variables
    <protocol>_proxy. If no proxy environment variables are set, in a
    Windows environment, proxy settings are obtained from the registry’s
    Internet Settings section and in a Mac OS X environment, proxy information
    is retrieved from the OS X System Configuration Framework.

    To disable autodetected proxy pass an empty dictionary.

  • 相关阅读:
    每个计算机科学专业的学生都应该知道些什么?
    Java中String类型转换成日期类型
    Java基础知识点总结
    JDBCJava连接MySql数据库
    MySql知识点全面总结
    PHP根据键值合并数组,键值一样的合并
    [幼儿园室外设计]幼儿园室外设计的四大原则是什么?
    [闭环步进电机]什么是闭环步进电机?闭环步进电机有什么优势?
    什么是php面向对象及面向对象的三大特性
    关于幼儿园空间设计常见的五大问题,你们园有注意吗?
  • 原文地址:https://www.cnblogs.com/lexus/p/2472934.html
Copyright © 2011-2022 走看看