I'm mixed on fixtures. One one hand, I've been impressed with how they compose and have let me do some great things. For example, I had system tests that need

I'm mixed on fixtures. One one hand, I've been impressed with how they compose and have let me do some great things. For example, I had system tests that needed hardware identifiers. I had a `conftest.py` to add CLI args for them. I then made fixtures to wrap the lookup of these. In the fixture, I marked it as Skip if the arg was missing. This was then propagated to all of the tests, only running the ones the end-user had the hardware for. On the other hand, when I need to vary the data between tests and that data is an input to something that I'd like to abstract the creation of, fixtures break down and I have to instead use a function call.