Source code to identify user through browser?

[Gilles]

Hello

I was wondering if some Python module were available to identify a
user through their browser, like it's done on the Panopticlick site:

http://panopticlick.eff.org/

I'd like to ban abusive users, and it seems like a good solution,
since few users will think of installing a different browser, and
there are few mainstream browsers anyway.

Thank you.