I have a test that tests class AbbreviationGenerator. Class names should use camel case, while method names should be lower case. Should I then name the test method test_AbbreviationGenerator or test_abbreviation_generator?
If the test is a method (as you say) then it's associated with a class, let's say the class is named AbbreviationGeneratorTest. Then you can simply name the method run.
Convention for test method names in Python