在python中实现模拟登录与提交表单的功能，必须建立cookie来保证session的建立。
例1，python模拟登录。
#!/usr/bin/env python
#--coding = UTF-8--
import sys, urllib2, urllib
import cookielib
cj = cookielib.CookieJar()
post_data = urllib.urlencode({"email": "*********@qq.com", "password": "*************"});
path = "http://www.renren.com/PLogin.do"
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
opener.addheaders = [('User-agent', 'Opera/9.23')]
urllib2.install_opener(opener)
req = urllib2.Request(path, post_data)
conn = urllib2.urlopen(req)
bd = urllib2.urlopen(urllib2.Request('http://guide.renren.com/guide')).read()
print bd;
例2，精简版——只能提供提交表单功能
由于session只能维持一个阶段。
#!/usr/bin/env python
#--coding = UTF-8--
import sys, urllib2, urllib
import cookielib
post_data = urllib.urlencode({"no": "10600140", "name": "zzy"});
path = "http://acm.zjnu.edu.cn/baoming/register.php"
header = {'User-agent': '01212/9.23'}
req = urllib2.Request(path, post_data,header)
conn = urllib2.urlopen(req)
print conn.read();