def test_has_invalid_chars(self): with self.subTest(): self.assertEqual(EP.has_invalid_chars('&'), '&') with self.subTest(): self.assertIsNone(EP.has_invalid_chars('a + b')) with self.subTest(): self.assertIsNone(EP.has_invalid_chars('a * b')) with self.subTest(): self.assertIsNone(EP.has_invalid_chars('a > b')) with self.subTest(): self.assertIsNone(EP.has_invalid_chars('a = b')) with self.subTest(): self.assertIsNone(EP.has_invalid_chars('~ b')) with self.subTest(): self.assertIsNone(EP.has_invalid_chars('( b )'))