I'm trying learn TDD in python. Unfortunately I have not found any PEPs about unittest.

Does one subclass of unittest.TestCase should contain all tests about one tested function?
What are the recommendations for naming classes, methods or test-files?
I usually make one class that handles the setup and tearing down for a particular test topic and subclass it for every single test. That is, one class for every test, with a name that conveys what is being tested. Nothing fancy.
Python unittest - division tests into classes/functions