Bittorrent up-to-date library written in python

Is there any up-开发者_StackOverflow社区to-date bittorrent library which is written in python and can be used on windows to write client? Some time ago bitcomet was written in python and it was ok. Any alternatives?

And second question: does bittorrent protocol change? For example what may happen if I will use old bitcomet library

The main bittorrent client, from bittorrent.com is all python based I believe. I have hacked it in the past, and it's very clean code easy to modify.