test_tzinfo.py 文件源码

def testUnknownOffsets(self):
        # This tzinfo behavior is required to make
        # datetime.time.{utcoffset, dst, tzname} work as documented.

        dst_tz = pytz.timezone('US/Eastern')

        # This information is not known when we don't have a date,
        # so return None per API.
        self.assertTrue(dst_tz.utcoffset(None) is None)
        self.assertTrue(dst_tz.dst(None) is None)
        # We don't know the abbreviation, but this is still a valid
        # tzname per the Python documentation.
        self.assertEqual(dst_tz.tzname(None), 'US/Eastern')