urllib.request.urlopen(url) with Authentication

You’re using HTTP Basic Authentication:

import urllib2, base64

request = urllib2.Request(url)
base64string = base64.b64encode('%s:%s' % (username, password))
request.add_header("Authorization", "Basic %s" % base64string)   
result = urllib2.urlopen(request)

So you should base64 encode the username and password and send it as an Authorization header.