urllib2 的优点

Python urllib2 发出的HTTP Request，能自动被Fiddler截获, 方便了调试。

Python 可以自动处理Cookie

urllib2 的缺点

Python urllib2 发出的http Request, 中的header 会被修改成“首字母大写”，

比如你的代码里写的header 是： content-TYPE=application/x-www-form-urlencoded ，会被修改为 Content-Type=application/x-www-form-urlencoded

实例一， Get方法，并且自定义header

# -* - coding: UTF-8 -* -  import urllib2request = urllib2.Request("http://www.baidu.com/")request.add_header('content-TYPE', 'application/x-www-form-urlencoded')response = urllib2.urlopen(request)print response.getcode()print response.geturl()print response.read()

实例二， post方法

# -* - coding: UTF-8 -* -  import urllib2import urllibrequest = urllib2.Request("http://passport.cnblogs.com/login.aspx")request.add_header('content-TYPE', 'application/x-www-form-urlencoded')data={
   "tbUserName":"test_username", "tbPassword":"test_password"}response = urllib2.urlopen(request, urllib.urlencode(data))print response.getcode()print response.geturl()print response.read()

实例三: Cookie 的处理

# -* - coding: UTF-8 -* -  import urllib2import urllibimport cookielibcj = cookielib.CookieJar()opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))request = urllib2.Request("https://dynamic.12306.cn/otsweb/")request.add_header('content-TYPE', 'application/x-www-form-urlencoded')data={
   "tbUserName":"test_username", "tbPassword":"test_password"}response = opener.open(request, urllib.urlencode(data))# send again, you will see cookie sent to web serverresponse = opener.open(request, urllib.urlencode(data))print response.getcode()print response.geturl()print response.read()