How To AutoLogin to Website And Navigate thereafter

[coldfire]

Can Some one help me or guide me the coding for automatic login to a website while keeping the session alive and navigating further into website for screen scraping using python.

I understand the scraping part but unable to Understand the Login part using any of the Lib

Urllib,Urlib2,BeautifulSoup,Mechanize,Re,requests,cookiejar etc


Thanks for the help.