Which Twitter wrapper libs support Python 3.x?

If you didn't already know them, you may want to take a look at the Python Twitter Tools that turned out from my bit of googling: they are listed among Python 3 packages on PyPI (under the package name twitter), and seem to be actively developed on GitHub.

Twython library now (as time of answering th question) fully support Python 3.x, not to mention that it's easy to use and implement, let alone their extensive documentation
As their official documentation says:

Seamless Python 3 support!

OAuth 2 Application Only (read-only) Support

Support for Twitter’s Streaming API

I've been using it for some time and it's working great for me, so consider giving it another chance.