Here is a piece of code that I use to fetch a web page HTML source (code) by its URL using Google App Engine:
from google.appengine.api import urlfetch
url = "http://www.google.com/"
result = urlfetch.fetch(url)
if result.status_code == 200:
print "content-type: text/plain"
print
print result.content
Everything is fine here, but sometimes I need to get an HTML source of a page from a site where I am registered and can only get an access to that page if I firstly pass my ID and password. (It can be any site, actually, like any mail-account-providing site like Yahoo: https://login.yahoo.com/config/mail?.src=ym&.intl=us or any other site where users get free accounts by firstly getting registered there). Can I somehow do it in Python (trough "Google App Engine")?