def test_mean_correctly_calculates_mean(self): values = [1, 2, 3, 4, 5, 6] self.assertEqual(mean(values), 3.5)
def test_mean_returns_none_for_no_values(self): values = [] self.assertEqual(mean(values), None)
def test_mean_returns_floating_point_number(self): values = [1, 2, 3, 4] mean_result = mean(values) self.assertIsInstance(mean_result, float)