def serialized(self):
        to_ret = {}
        for group, requirements in self.items():
            to_ret[group] = [str(requirement) for requirement in requirements]
        return to_ret
def test_regex_bad_input():
    cases = (
        'abc',
        '123abc',
        'abc123',
        '',
    )

    num_only = inputs.regex(r'^[0-9]+$')

    for value in cases:
        yield assert_raises, ValueError, lambda: num_only(value)