Python Scripts to logon to websites

[BartlebyScrivener]

New to Python and Programming. Trying to make scripts that will open
sites and automatically log me on.

The following example is from the urllib2 module.

What are "realm" and "host" in this example.

import urllib2
# Create an OpenerDirector with support for Basic HTTP
Authentication...
auth_handler = urllib2.HTTPBasicAuthHandler()
auth_handler.add_password('realm', 'host', 'username', 'password')
opener = urllib2.build_opener(auth_handler)
# ...and install it globally so it can be used with urlopen.
urllib2.install_opener(opener)
urllib2.urlopen('http://www.example.com/login.html')

Does anyone have a simple example of a script that opens, say, gmail or
some other commonly accessed site that requires a username and password
so that I can see how one is made?

Thanks very much for any help.

rpd