Using pytest as a test runner

One thing that surprisingly many people don't know is that pytest can run unittest suites out of the box, without any modifications.

For example:

class Test(unittest.TestCase):

    @classmethod
    def setUpClass(cls):
        cls.temp_dir = Path(tempfile.mkdtemp())
        cls.filepath = cls.temp_dir / "data.csv"
        cls.filepath.write_text(DATA.strip())

    @classmethod
    def tearDownClass(cls):
        shutil.rmtree(cls.temp_dir)

    def setUp(self):
        self.grids = list(iter_grids_from_csv(self.filepath))

    def test_read_properties(self):
        self.assertEqual(self.grids[0], GridData("Main Grid", 48, 44))
        self.assertEqual(self.grids[1], GridData("2nd Grid", 24, 21))
        self.assertEqual(self.grids[2], GridData("3rd Grid", 24, 48))

    def test_invalid_path(self):
        with self.assertRaises(IOError):
            list(iter_grids_from_csv(Path("invalid file")))

    @unittest.expectedFailure
    def test_write_properties(self...