求个python模拟登录代码

以下是我的尝试，没有完成，谁能帮帮忙？
#!/usr/bin/python
# -*- coding: utf8 -*-
import re
import urllib
import urllib2
import cookielib

class Cnzz:
def __init__(self):
self.UserName=''
self.Password=''
self.cookie=cookielib.CookieJar()
self.opener=urllib2.build_opener(urllib2.HTTPCookieProcessor(self.cookie))
self.opener.addheaders=[('User-agent','Mozilla/5.0'),('Accept-Charset','gb2312')]
urllib2.install_opener(self.opener)

def login(self,username,password):
self.UserName=username
post_data=urllib.urlencode({'username':username,'password':password,'list':'1'})
path = 'http://www.cnzz.com/index.php'
req = urllib2.Request(url=path, data=post_data)
conn = urllib2.urlopen(req)

conn2 = urllib2.urlopen(urllib2.Request(url='http://new.cnzz.com/v1/main.php?s=site_list')).read()

return conn2

if __name__=="__main__":
cnzz=Cnzz()
y=cnzz.login('username','password')
print unicode(y,'utf-8','ignore').encode('gb2312','ignore')