def test_same_letter(self): self.assertEqual(count_letters("a"), {"a":1}) self.assertEqual(count_letters("aa"), {"a":2})
def test_distinct_letters(self): self.assertEqual(count_letters("ab"), {"a":1, "b":1})
def test_if_exist(self): self.assertEqual(count_letters(""), {})
def test_different_letters(self): self.assertEqual(count_letters("b"), {"b":1})