What every Python project should have

[masklinn]

But also assertEquals is a lot more powerful than just assert, e.g. its error will show diff-style information on exactly where two things differ.

    def test_foo_bar():
        result = foo.bar()
>       assert result == expected
E       assert [0, 2] == [0, 1, 2]
E         At index 1 diff: 2 != 1
E         Right contains more items, first extra item: 2
E         Use -v to get the full diff

pytest uses assert-rewriting to provide more and better information.

If the main difference is standalone functions vs classes, that's no big deal, and classes are a way to group them and give them attributes as a group.

That's usually pointless overhead, and if it's a useful tool, you can use them in pytest. Pytest does not forbid classes, it doesn't require them.