pytest has no reference documentation (as far as I can tell). This is problematic, because while the documentation tells me pytest's basic usage, I have no idea what anything actually does.

Even something as simple as pytest.fixture is undocumented. What does it do? What arguments does it take? What, specifically, do scope='function', scope='class', and scope='session' do?

It's quite possible however that I simply haven't found the documentation, as silly as that sounds. Consider for example this page, which doesn't seem to be linked from anywhere and hence isn't included in the PDF documentation either. Perhaps there's some reference documentation hidden in the pytest Deep web that I'm missing?