I see you're using the "xunit style" tests here.  Are you familiar with the pytests fixtures that can be used to acheive the same goal (http://pytest.org/latest/fixture.html ) ? I haven't really tested this, but the docs there seem to indicate the fixtures can be substantially faster because you can generate the fixture once per module (or class, or whatever).

If you know about them and just don't like them for some reason, that's fine.  Just thought I'd mention in case you hadn't looked seen them.