Method test_tz_before_only

Lib/test/test_zoneinfo/test_zoneinfo.py:702–736

(self)

            self.assertIs(t.dst(), None)

    def test_tz_before_only(self):
        # From RFC 8536 Section 3.2:
        #
        #   If there are no transitions, local time for all timestamps is
        #   specified by the TZ string in the footer if present and nonempty;
        #   otherwise, it is specified by time type 0.

        offsets = [
            ZoneOffset("STD", ZERO, ZERO),
            ZoneOffset("DST", ONE_H, ONE_H),
        ]

        for offset in offsets:
            # Phantom transition to set time type 0.
            transitions = [
                ZoneTransition(None, offset, offset),
            ]

            after = ""

            zf = self.construct_zone(transitions, after)
            zi = self.klass.from_file(zf)

            dts = [
                datetime(1900, 1, 1),
                datetime(1970, 1, 1),
                datetime(2000, 1, 1),
            ]

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

    def test_empty_zone(self):
        zf = self.construct_zone([], "")