用python写了一个csdn的模拟登录程序，运行失败了

[dystopiaz]

# -*- coding:utf-8 -*-
import sys
from fileinput import filename
reload(sys)
sys.setdefaultencoding('utf-8')
# -*- coding:utf-8 -*-
import urllib
import urllib2
import re
import hashlib
import cookielib
import webbrowser

cookies = cookielib.CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookies))


loginurl = 'https://passport.csdn.net/account/login'
loginheaders = {
           'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
           #'Accept-Encoding':'gzip,deflate,sdch',
           'Accept-Language':'zh-CN,zh;q=0.8',
           'Host':'my.csdn.net',
           'Proxy-Connection':'keep-alive',
           'Referer':'http://passport.csdn.net/account/login?from=http%3A%2F%2Fmy.csdn.net%2Fmy%2Fmycsdn',
           'User-Agent':'Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/38.0.2125.101 Safari/537.36',
           }

result = urllib2.urlopen(url = loginurl)
content = result.read().encode('UTF-8')
print content


pattern = re.compile('name="lt" value="(.*?)"')
match = re.search(pattern,content)
lt_code = match.group(1)
print lt_code

pattern = re.compile('name="execution" value="(.*?)"')
match = re.search(pattern,content)
execution_code = match.group(1)
print execution_code

postdata = urllib.urlencode({
            'username':'这里填我的用户名',
            'password':'这里填我的密码',
            'rememberMe':'true',
            'lt':lt_code,
            'execution':execution_code,
            'eventId':'submit',
            'l':'登 录',
         })

req = urllib2.Request(url = 'https://passport.csdn.net/account/login',data = postdata,headers = loginheaders)

result = opener.open(req)
content = result.read().encode('UTF-8')
print content

显示在req这里出了问题，求大神解答一下，多谢了

引用

LT-2250024-Rsx6xFCktUTcidVsWEilzjawsdbpbX
e1s1
Traceback (most recent call last):
File "D:\Program Files (x86)\eclipse-java-luna-SR1a-win32-x86_64\eclipse\workspace\csdn\src\csdn.py", line 56, in <module>
result = opener.open(req)
File "D:\python2.7\lib\urllib2.py", line 437, in open
response = meth(req, response)
File "D:\python2.7\lib\urllib2.py", line 550, in http_response
'http', request, response, code, msg, hdrs)
File "D:\python2.7\lib\urllib2.py", line 475, in error
return self._call_chain(*args)
File "D:\python2.7\lib\urllib2.py", line 409, in _call_chain
result = func(*args)
File "D:\python2.7\lib\urllib2.py", line 558, in http_error_default
raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
urllib2.HTTPError: HTTP Error 404: Not Found