Method test_no_tz_str

Lib/test/test_zoneinfo/test_zoneinfo.py:659–700

(self)

                self.assertEqual(dt.dst(), DST.dst)

    def test_no_tz_str(self):
        STD = ZoneOffset("STD", ONE_H, ZERO)
        DST = ZoneOffset("DST", 2 * ONE_H, ONE_H)

        transitions = []
        for year in range(1996, 2000):
            transitions.append(
                ZoneTransition(datetime(year, 3, 1, 2), STD, DST)
            )
            transitions.append(
                ZoneTransition(datetime(year, 11, 1, 2), DST, STD)
            )

        after = ""

        zf = self.construct_zone(transitions, after)

        # According to RFC 8536, local times after the last transition time
        # with an empty TZ string are unspecified. We will go with "hold the
        # last transition", but the most we should promise is "doesn't crash."
        zi = self.klass.from_file(zf)

        cases = [
            (datetime(1995, 1, 1), STD),
            (datetime(1996, 4, 1), DST),
            (datetime(1996, 11, 2), STD),
            (datetime(2001, 1, 1), STD),
        ]

        for dt, offset in cases:
            dt = dt.replace(tzinfo=zi)
            with self.subTest(dt=dt):
                self.assertEqual(dt.tzname(), offset.tzname)
                self.assertEqual(dt.utcoffset(), offset.utcoffset)
                self.assertEqual(dt.dst(), offset.dst)

        # Test that offsets return None when using a datetime.time
        t = time(0, tzinfo=zi)
        with self.subTest("Testing datetime.time"):
            self.assertIs(t.tzname(), None)
            self.assertIs(t.utcoffset(), None)
            self.assertIs(t.dst(), None)

    def test_tz_before_only(self):
        # From RFC 8536 Section 3.2: