def test_is_numeric_method(self):
self.assertEqual(DataCleaner.is_numeric(1), True)
self.assertEqual(DataCleaner.is_numeric("1"), True)
self.assertEqual(DataCleaner.is_numeric(1.0), True)
self.assertEqual(DataCleaner.is_numeric("1.0"), True)
self.assertEqual(DataCleaner.is_numeric("nan"), False)
self.assertEqual(DataCleaner.is_numeric("a"), False)
self.assertEqual(DataCleaner.is_numeric(None), False)
def test_to_string_method(self):
self.assertEqual(DataCleaner.to_string(0), '0')
def test_to_numeric_method(self):
self.assertEqual(DataCleaner.to_numeric('0'), 0)