什麽是 cookie：某些網站為了辨別用戶身份，進行 session 跟蹤而存儲在用戶本地上的數據，通過 cookie 可以訪問網站的其他頁面，否則是禁止訪問的

如何獲取 cookie ：

In [1]: import urllib2, cookielib

In [2]: cookie = cookielib.CookieJar()    # 獲取存在本機的cookie消息，但第一次獲取為空，只有訪問了一個URL之後才有cookie信息

In [3]: handler = urllib2.HTTPCookieProcessor(cookie)      # 創建一個處理器，用於處理cookie信息
 


In [4]: opener = urllib2.build_opener(handler)             # 通過cookie處理器構建opener,使得opener跟CookieJar對象綁定

In [5]: response = opener.open(‘http://www.baidu.com/‘)    # 使用opener來訪問一個URL便會收集到cookie信息

In [6]: for i in cookie:
   ....:     print ‘%s: %s‘ % (i.name, i.value)
   ....:     
BAIDUID: D9487EEE0A9D16C06CA7517EACC00798:FG=1
 

BIDUPSID: D9487EEE0A9D16C06CA7517EACC00798
H_PS_PSSID: 1445_21112_18560_17001_25178_20930
PSTM: 1514119274
BDSVRTM: 0
BD_HOME: 0

實例：通過 cookie 自動登錄企業郵箱

#!/usr/bin/env python
#-*- coding: utf8 -*-

import re
import urllib
import urllib2
import cookielib

class MyMail(object):
    def __init__(self):
        self.headers 
 
= {‘User-Agent‘: ‘Mozilla/5.0 (Windows NT6.1; rv:47.0) Gecko/20100101 Firefox/47.0‘}  
        self.baseURL = ‘https://bjmail.clustertech.com/roundcude/‘
        self.loginURL = self.baseURL + ‘?_task=login‘
    
    def getPage(self):
        self.cookie = cookielib.CookieJar()
        handler = urllib2.HTTPCookieProcessor(self.cookie)
        self.opener = urllib2.build_opener(handler)
        try:
            request = urllib2.Request(url=self.baseURL, headers=self.headers)
            response = self.opener.open(request)
            return response.read()
        except urllib2.URLError, e:
            if hasattr(e, ‘reason‘):
                print "連接服務器失敗，錯誤原因", e.reason
                return None
                
    def getToken(self):
        page = self.getPage()
        re_token = re.compile(r‘<form.*?<input.*?value="(.*?)".*?>‘, re.S)
        token = re_token.search(page)
        if token:
            return token.group(1)
        else:  
            return None

    def login(self):
        data = {"_token":self.getToken(),
                "_task":"login",
                "_action":"login",
                "_timezone":"Asia/Shanghai",
                "_url":"",
                "_user":"zyli",
                "_pass":"1234.qwe"}
        self.postdata = urllib.urlencode(data)
        try:
            request = urllib2.Request(url = self.loginURL,
                                      data = self.postdata,
                                      headers = self.headers)
            response  = self.opener.open(request)
            print response.read()
        except urllib2.URLError, e:
            print e

gs = MyMail()
gs.getToken()
gs.login()

通過 cookie 信息實現自動登錄