pass session cookies in http header with python urllib2?

Question

I'm trying to write a simple script to log into Wikipedia and perform some actions on my user page, using the Mediawiki api. However, I never seem to get past the first login request (from this page: https://en.wikipedia.org/wiki/Wikipedia:Creating_a_bot#Logging_in). I don't think the session cookie that I set is being sent. This is my code so far:

import Cookie, urllib, urllib2, xml.etree.ElementTree

url = 'https://en.wikipedia.org/w/api.php?action=login&format=xml'
username = 'user'
password = 'password'

user_data = [('lgname', username), ('lgpassword', password)]

#Login step 1
#Make the POST request
request = urllib2.Request(url)
data = urllib.urlencode(user_data)
login_raw_data1 = urllib2.urlopen(request, data).read()

#Parse the XML for the login information
login_data1 = xml.etree.ElementTree.fromstring(login_raw_data1)
login_tag = login_data1.find('login')
token = login_tag.attrib['token']
cookieprefix = login_tag.attrib['cookieprefix']
sessionid = login_tag.attrib['sessionid']

#Set the cookies
cookie = Cookie.SimpleCookie()
cookie[cookieprefix + '_session'] = sessionid

#Login step 2
request = urllib2.Request(url)
session_cookie_header = cookieprefix+'_session='+sessionid+'; path=/; domain=.wikipedia.org; HttpOnly'

request.add_header('Set-Cookie', session_cookie_header)
user_data.append(('lgtoken', token))
data = urllib.urlencode(user_data)

login_raw_data2 = urllib2.urlopen(request, data).read()

I think the problem is somewhere in the request.add_header('Set-Cookie', session_cookie_header) line, but I don't know for sure. How do I use these python libraries to send cookies in the header with every request (which is necessary for a lot of API functions).

Answer 1

The latest version of requests has support for sessions (as well as being really simple to use and generally great):

with requests.session() as s: 
    s.post(url, data=user_data)
    r = s.get(url_2)