如何使用urllib2将数据发布到认证服务器

Question

我有一些python代码，它使用requests模块访问特定网站上的页面。我尝试使用标准libraby来重做这个，特别是urllib2。你知道吗

以下是使用requests的工作代码：

import requests

#Now create a session
s = requests.session()

#look at login screen at http://supercoach.heraldsun.com.au/
#looking closely at what gets 'POSTed' when you submit the form
#it is sending the following params:

data = {
    'username'      :'test_account@scscorecollector.info',
    'password'      :'magicword',
    'remember_me'   :'on',
    'channel'       :'pc',
    'site'          :'HeraldSun',
    'cancelUrl'     :'http://supercoach.heraldsun.com.au/?identity-login-error=1',
    'relayState'    :'http://supercoach.heraldsun.com.au/?login=1',
    'location'      :'http://saml.cam.idmndm.com',
}




#This data gets POSTed to https://idp.news.com.au/idp/Authn/rest, but we want to read  a differnet url
url_post = 'https://idp.news.com.au/idp/Authn/rest/'
url_read ='http://supercoach.heraldsun.com.au/team/other_teams?tid=11088'


r = s.post(url_post, data=data)

#Now that you are logged in, you can call the URL we want to read:

r = s.get(url_read)
print r

#<Response [200]>

现在，我正在努力研究如何用urllib2复制这一点。下面是我的不工作的尝试。你知道吗

import urllib2
import urllib
import cookielib

data = {'username'      :'test_account@scscorecollector.info',
    'password'      :'magicword',
    'remember_me'   :'on',
    'channel'       :'pc',
    'site'          :'HeraldSun',
    'cancelUrl'     :'http://supercoach.heraldsun.com.au/?identity-login-error=1',
    'relayState'    :'http://supercoach.heraldsun.com.au/?login=1',
    'location'      :'http://saml.cam.idmndm.com'}

#some data
url_post = 'https://idp.news.com.au/idp/Authn/rest'
url_read ='http://supercoach.heraldsun.com.au/team/other_teams?tid=11088'
user_agent = 'Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Firefox/31.0'

headers = { 'User-Agent' : user_agent }
data_encode = urllib.urlencode(data)

# setup cookie handler and create opener
cookie_jar = cookielib.LWPCookieJar()
cookie = urllib2.HTTPCookieProcessor(cookie_jar)
opener = urllib2.build_opener(cookie)

# post to 
req = urllib2.Request(url_post, data_encode, headers)
req.get_method = lambda: 'POST'
response = opener.open(req)

这将返回以下错误

urllib2.HTTPError: HTTP Error 302: The HTTP server returned a redirect error that would lead to an infinite loop.
The last 30x error message was:
Found

这是因为我发布到一个不同于我想阅读的url吗？有人能为这个问题提供解决办法吗？你知道吗

谢谢 约翰