PyUSB provides USB access on the Python language.
The documentation is misleading. It implies that this provides actual access to USB functionality from Python. It doesn't. It's just a Python front end to a platform-specific "back end" which may be available from another source. There's an old Windows back-end at "http://www.craftedge.com/products/libusb.html", but it was written for Windows XP, and can supposedly be run in "compatibility mode" on Windows Vista. Current versions of Windows, who knows? It's not open source, and it comes from someone who sells paper-cutting machines for crafters. Not too helpful.