def test_parse_ms_precision(): base = '2013-07-03T16:34:52' digits = '1234567890' parsed = jsonutil.parse_date(base) nt.assert_is_instance(parsed, datetime.datetime) for i in range(len(digits)): ts = base + '.' + digits[:i] parsed = jsonutil.parse_date(ts) if i >= 1 and i <= 6: nt.assert_is_instance(parsed, datetime.datetime) else: nt.assert_is_instance(parsed, str)