I was looking around, and couldn't find the Python equivalent of browscap (that I've used in PHP to detect what browser a given user-agent string is.
I'm hoping I'm not going to have to write my own.. :P
Check this out, it should do what you want: browscap.ini-parser.
Please note that even though it is on the Django Snippets website it is standalone and you can use it with whatever setup you have.