[mivade]

If for no other reason, pytest requires a lot less boilerplate.

Pytest fixtures are also quite a bit more flexible than unittest's setUp and tearDown methods, although they take a little while to really understand (at least they did for me) since they use some magic.

[bpicolo]

Yield fixtures are just awesome for mocking, but the magical global dependency injection definitely makes you feel a bit weird on occasion

[quodlibetor]

especially in combination with pytest-mock.