Python datetime.tzinfo() Examples

def testGapPositiveUTCOffset(self):
        # Test that we don't have a problem around gaps.
        tzname = 'AUS Eastern Standard Time'
        args = self.get_args(tzname)

        with self.context(tzname):
            SYD = self.tzclass(*args)

            t_n, t0_u, t1_u = self.get_utc_transitions(SYD, 2012, True)

            t0 = t0_u.astimezone(SYD)
            t1 = t1_u.astimezone(SYD)

            self.assertEqual(t0.replace(tzinfo=None), t_n)

            self.assertEqual(t1.replace(tzinfo=None), t_n + timedelta(hours=2))

            self.assertEqual(t0.utcoffset(), timedelta(hours=10))
            self.assertEqual(t1.utcoffset(), timedelta(hours=11)) 

def testFoldPositiveUTCOffset(self):
        # Test that we can resolve ambiguous times
        tzname = self._get_tzname('Australia/Sydney')

        with self._gettz_context(tzname):
            SYD = self.gettz(tzname)

            t0_u = datetime(2012, 3, 31, 15, 30, tzinfo=tz.tzutc())  # AEST
            t1_u = datetime(2012, 3, 31, 16, 30, tzinfo=tz.tzutc())  # AEDT

            t0_syd0 = t0_u.astimezone(SYD)
            t1_syd1 = t1_u.astimezone(SYD)

            self.assertEqual(t0_syd0.replace(tzinfo=None),
                             datetime(2012, 4, 1, 2, 30))

            self.assertEqual(t1_syd1.replace(tzinfo=None),
                             datetime(2012, 4, 1, 2, 30))

            self.assertEqual(t0_syd0.utcoffset(), timedelta(hours=11))
            self.assertEqual(t1_syd1.utcoffset(), timedelta(hours=10)) 

def testGapPositiveUTCOffset(self):
        # Test that we don't have a problem around gaps.
        tzname = self._get_tzname('Australia/Sydney')

        with self._gettz_context(tzname):
            SYD = self.gettz(tzname)

            t0_u = datetime(2012, 10, 6, 15, 30, tzinfo=tz.tzutc())  # AEST
            t1_u = datetime(2012, 10, 6, 16, 30, tzinfo=tz.tzutc())  # AEDT

            t0 = t0_u.astimezone(SYD)
            t1 = t1_u.astimezone(SYD)

            self.assertEqual(t0.replace(tzinfo=None),
                             datetime(2012, 10, 7, 1, 30))

            self.assertEqual(t1.replace(tzinfo=None),
                             datetime(2012, 10, 7, 3, 30))

            self.assertEqual(t0.utcoffset(), timedelta(hours=10))
            self.assertEqual(t1.utcoffset(), timedelta(hours=11)) 

def strptime(data, fmt):
        if fmt.endswith('%z'):
            date = datetime.strptime(data[:-5], fmt[:-2])

            try:
                sign = {'-': -1, '+': 1}[data[-5]]
                hours = sign * int(data[-4:-2])
                minutes = sign * int(data[-2:])
            except KeyError:
                raise ValueError(
                    "time data '{}' does not match format '{}'.".format(
                        data,
                        fmt))

            date = date.replace(tzinfo=timezone(timedelta(hours=hours,
                                                          minutes=minutes)))
        else:
            date = datetime.strptime(data, fmt)

        return date 

def testFoldNegativeUTCOffset(self):
            # Test that we can resolve ambiguous times
            tzname = self._get_tzname('America/Toronto')

            with self._gettz_context(tzname):
                TOR = self.gettz(tzname)

                t0_u = datetime(2011, 11, 6, 5, 30, tzinfo=tz.tzutc())
                t1_u = datetime(2011, 11, 6, 6, 30, tzinfo=tz.tzutc())

                t0_tor = t0_u.astimezone(TOR)
                t1_tor = t1_u.astimezone(TOR)

                self.assertEqual(t0_tor.replace(tzinfo=None),
                                 datetime(2011, 11, 6, 1, 30))

                self.assertEqual(t1_tor.replace(tzinfo=None),
                                 datetime(2011, 11, 6, 1, 30))

                self.assertNotEqual(t0_tor.tzname(), t1_tor.tzname())
                self.assertEqual(t0_tor.utcoffset(), timedelta(hours=-4.0))
                self.assertEqual(t1_tor.utcoffset(), timedelta(hours=-5.0)) 

def testFoldLondon(self):
        tzname = self._get_tzname('Europe/London')

        with self._gettz_context(tzname):
            LON = self.gettz(tzname)
            UTC = tz.tzutc()

            t0_u = datetime(2013, 10, 27, 0, 30, tzinfo=UTC)   # BST
            t1_u = datetime(2013, 10, 27, 1, 30, tzinfo=UTC)   # GMT

            t0 = t0_u.astimezone(LON)
            t1 = t1_u.astimezone(LON)

            self.assertEqual(t0.replace(tzinfo=None),
                             datetime(2013, 10, 27, 1, 30))

            self.assertEqual(t1.replace(tzinfo=None),
                             datetime(2013, 10, 27, 1, 30))

            self.assertEqual(t0.utcoffset(), timedelta(hours=1))
            self.assertEqual(t1.utcoffset(), timedelta(hours=0)) 

def _isdst(self, dt):
        if not self.hasdst:
            return False
        elif dt is None:
            return None

        transitions = self.transitions(dt.year)

        if transitions is None:
            return False

        dt = dt.replace(tzinfo=None)

        isdst = self._naive_isdst(dt, transitions)

        # Handle ambiguous dates
        if not isdst and self.is_ambiguous(dt):
            return not self._fold(dt)
        else:
            return isdst 

def testInZoneFoldEquality(self):
        # Two datetimes in the same zone are considered to be equal if their
        # wall times are equal, even if they have different absolute times.

        tzname = self._get_tzname('America/New_York')

        with self._gettz_context(tzname):
            NYC = self.gettz(tzname)
            UTC = tz.tzutc()

            dt0 = datetime(2011, 11, 6, 1, 30, tzinfo=NYC)
            dt1 = tz.enfold(dt0, fold=1)

            # Make sure these actually represent different times
            self.assertNotEqual(dt0.astimezone(UTC), dt1.astimezone(UTC))

            # Test that they compare equal
            self.assertEqual(dt0, dt1) 

def is_ambiguous(self, dt):
        """
        Whether or not the "wall time" of a given datetime is ambiguous in this
        zone.

        :param dt:
            A :py:class:`datetime.datetime`, naive or time zone aware.


        :return:
            Returns ``True`` if ambiguous, ``False`` otherwise.

        .. versionadded:: 2.6.0
        """
        if not self.hasdst:
            return False

        start, end = self.transitions(dt.year)

        dt = dt.replace(tzinfo=None)
        return (end <= dt < end + self._dst_base_offset) 

def get_utc_transitions(self, tzi, year, gap):
        dston, dstoff = tzi.transitions(year)
        if gap:
            t_n = dston - timedelta(minutes=30)

            t0_u = t_n.replace(tzinfo=tzi).astimezone(tz.tzutc())
            t1_u = t0_u + timedelta(hours=1)
        else:
            # Get 1 hour before the first ambiguous date
            t_n = dstoff - timedelta(minutes=30)

            t0_u = t_n.replace(tzinfo=tzi).astimezone(tz.tzutc())
            t_n += timedelta(hours=1)                   # Naive ambiguous date
            t0_u = t0_u + timedelta(hours=1)            # First ambiguous date
            t1_u = t0_u + timedelta(hours=1)            # Second ambiguous date

        return t_n, t0_u, t1_u 

def testFoldNegativeUTCOffset(self):
        # Test that we can resolve ambiguous times
        tzname = 'Eastern Standard Time'
        args = self.get_args(tzname)

        with self.context(tzname):
            TOR = self.tzclass(*args)

            t_n, t0_u, t1_u = self.get_utc_transitions(TOR, 2011, False)

            t0_tor = t0_u.astimezone(TOR)
            t1_tor = t1_u.astimezone(TOR)

            self.assertEqual(t0_tor.replace(tzinfo=None), t_n)
            self.assertEqual(t1_tor.replace(tzinfo=None), t_n)

            self.assertNotEqual(t0_tor.tzname(), t1_tor.tzname())
            self.assertEqual(t0_tor.utcoffset(), timedelta(hours=-4.0))
            self.assertEqual(t1_tor.utcoffset(), timedelta(hours=-5.0)) 

def _mock(self, context=None):
        dt = datetime.datetime(
               year=random.randrange(600) + 1900,
               month=random.randrange(12) + 1,
               day=random.randrange(28) + 1,
               hour=random.randrange(24),
               minute=random.randrange(60),
               second=random.randrange(60),
               microsecond=random.randrange(1000000))

        if self.tzd == 'reject' or \
           self.drop_tzinfo or \
           self.tzd == 'allow' and random.randrange(2):
            return dt
        elif self.convert_tz:
            return dt.replace(tzinfo=self.UTC)
        else:
            return dt.replace(tzinfo=self.offset_timezone(hours=random.randrange(-12, 15),
                                                          minutes=random.choice([0, 30, 45]))) 

def check_date_limit(self, data, verbose=False):
        """
        Validate date limits.
        """
        if self.upper_date_limit or self.lower_date_limit:
            date_fmt = '%a %b %d %H:%M:%S +0000 %Y'
            tweet_date = \
                datetime.strptime(data['created_at'],
                                  date_fmt).replace(tzinfo=UTC)
            if (self.upper_date_limit and tweet_date > self.upper_date_limit) or \
               (self.lower_date_limit and tweet_date < self.lower_date_limit):
                if self.upper_date_limit:
                    message = "earlier"
                    date_limit = self.upper_date_limit
                else:
                    message = "later"
                    date_limit = self.lower_date_limit
                if verbose:
                    print("Date limit {0} is {1} than date of current tweet {2}".\
                      format(date_limit, message, tweet_date))
                self.do_stop = True 

def testGapNegativeUTCOffset(self):
        # Test that we don't have a problem around gaps.
        tzname = 'Eastern Standard Time'
        args = self.get_args(tzname)

        with self.context(tzname):
            TOR = self.tzclass(*args)

            t_n, t0_u, t1_u = self.get_utc_transitions(TOR, 2011, True)

            t0 = t0_u.astimezone(TOR)
            t1 = t1_u.astimezone(TOR)

            self.assertEqual(t0.replace(tzinfo=None),
                             t_n)

            self.assertEqual(t1.replace(tzinfo=None),
                             t_n + timedelta(hours=2))

            self.assertNotEqual(t0.tzname(), t1.tzname())
            self.assertEqual(t0.utcoffset(), timedelta(hours=-5.0))
            self.assertEqual(t1.utcoffset(), timedelta(hours=-4.0)) 

def testTzwinName(self):
        # https://github.com/dateutil/dateutil/issues/143
        tw = tz.tzwin('Eastern Standard Time')

        # Cover the transitions for at least two years.
        ESTs = 'Eastern Standard Time'
        EDTs = 'Eastern Daylight Time'
        transition_dates = [(datetime(2015, 3, 8, 0, 59), ESTs),
                            (datetime(2015, 3, 8, 3, 1), EDTs),
                            (datetime(2015, 11, 1, 0, 59), EDTs),
                            (datetime(2015, 11, 1, 3, 1), ESTs),
                            (datetime(2016, 3, 13, 0, 59), ESTs),
                            (datetime(2016, 3, 13, 3, 1), EDTs),
                            (datetime(2016, 11, 6, 0, 59), EDTs),
                            (datetime(2016, 11, 6, 3, 1), ESTs)]

        for t_date, expected in transition_dates:
            self.assertEqual(t_date.replace(tzinfo=tw).tzname(), expected) 

def testInZoneFoldEquality(self):
        # Two datetimes in the same zone are considered to be equal if their
        # wall times are equal, even if they have different absolute times.
        tzname = 'Eastern Standard Time'
        args = self.get_args(tzname)

        with self.context(tzname):
            NYC = self.tzclass(*args)
            UTC = tz.tzutc()

            t_n, t0_u, t1_u = self.get_utc_transitions(NYC, 2011, False)

            dt0 = t_n.replace(tzinfo=NYC)
            dt1 = tz.enfold(dt0, fold=1)

            # Make sure these actually represent different times
            self.assertNotEqual(dt0.astimezone(UTC), dt1.astimezone(UTC))

            # Test that they compare equal
            self.assertEqual(dt0, dt1)

###
# Test Cases 

def _fold_status(self, dt_utc, dt_wall):
        """
        Determine the fold status of a "wall" datetime, given a representation
        of the same datetime as a (naive) UTC datetime. This is calculated based
        on the assumption that ``dt.utcoffset() - dt.dst()`` is constant for all
        datetimes, and that this offset is the actual number of hours separating
        ``dt_utc`` and ``dt_wall``.

        :param dt_utc:
            Representation of the datetime as UTC

        :param dt_wall:
            Representation of the datetime as "wall time". This parameter must
            either have a `fold` attribute or have a fold-naive
            :class:`datetime.tzinfo` attached, otherwise the calculation may
            fail.
        """
        if self.is_ambiguous(dt_wall):
            delta_wall = dt_wall - dt_utc
            _fold = int(delta_wall == (dt_utc.utcoffset() - dt_utc.dst()))
        else:
            _fold = 0

        return _fold 

def testTimeOnlyGettzDST(self):
        # gettz returns None
        tz_get = self.gettz('Europe/Minsk')
        self.assertIs(dt_time(13, 20, tzinfo=tz_get).dst(), None) 

def testTimeOnlyDSTLocalUTC(self):
        with TZEnvContext(self.UTC):
            self.assertEqual(dt_time(13, 20, tzinfo=tz.tzlocal()).dst(),
                             timedelta(0)) 

def testTimeOnlyGettz(self):
        # gettz returns None
        tz_get = self.gettz('Europe/Minsk')
        self.assertIs(dt_time(13, 20, tzinfo=tz_get).utcoffset(), None) 

def testFileLastTransition(self):
        # After the last transition, it goes to standard time in perpetuity
        tzc = tz.tzfile(BytesIO(base64.b64decode(TZFILE_EST5EDT)))
        self.assertEqual(datetime(2037, 10, 25, 0, 59, tzinfo=tzc).tzname(),
                         "EDT")

        last_date = tz.enfold(datetime(2037, 10, 25, 1, 00, tzinfo=tzc), fold=1)
        self.assertEqual(last_date.tzname(),
                         "EST")

        self.assertEqual(datetime(2038, 5, 25, 12, 0, tzinfo=tzc).tzname(),
                         "EST") 

def _test_us_zone(self, tzc, func, values, start):
        if start:
            dt1 = datetime(2003, 3, 9, 1, 59)
            dt2 = datetime(2003, 3, 9, 2, 00)
            fold = [0, 0]
        else:
            dt1 = datetime(2003, 11, 2, 0, 59)
            dt2 = datetime(2003, 11, 2, 1, 00)
            fold = [0, 1]

        dts = (tz.enfold(dt.replace(tzinfo=tzc), fold=f)
               for dt, f in zip((dt1, dt2), fold))

        for value, dt in zip(values, dts):
            self.assertEqual(func(dt), value) 

def testTimeOnlyUTC(self):
        # https://github.com/dateutil/dateutil/issues/132
        # tzutc doesn't care
        tz_utc = tz.tzutc()
        self.assertEqual(dt_time(13, 20, tzinfo=tz_utc).utcoffset(),
                         timedelta(0)) 

def testTimeOnlyOffsetLocalDST(self):
        with TZEnvContext(self.TZ_EST):
            self.assertIs(dt_time(13, 20, tzinfo=tz.tzlocal()).utcoffset(),
                          None) 

def testTimeOnlyOffsetLocalUTC(self):
        with TZEnvContext(self.UTC):
            self.assertEqual(dt_time(13, 20, tzinfo=tz.tzlocal()).utcoffset(),
                             timedelta(0)) 

def _testTzFunc(self, tzval, func, std_val, dst_val):
        """
        This generates tests about how the behavior of a function ``func``
        changes between STD and DST (e.g. utcoffset, tzname, dst).

        It assume that DST starts the 2nd Sunday in March and ends the 1st
        Sunday in November
        """
        with TZEnvContext(tzval):
            dt1 = datetime(2015, 2, 1, 12, 0, tzinfo=tz.tzlocal())  # STD
            dt2 = datetime(2015, 5, 1, 12, 0, tzinfo=tz.tzlocal())  # DST

            self.assertEqual(func(dt1), std_val)
            self.assertEqual(func(dt2), dst_val) 

def testAmbiguity(self):
        # Pick an arbitrary datetime, this should always return False.
        dt = datetime(2011, 9, 1, 2, 30, tzinfo=tz.tzoffset("EST", -5 * 3600))

        self.assertFalse(tz.datetime_ambiguous(dt)) 

def testTzNameNone(self):
        gmt5 = tz.tzoffset(None, -18000)       # -5:00
        self.assertIs(datetime(2003, 10, 26, 0, 0, tzinfo=gmt5).tzname(),
                      None) 

def testAmbiguity(self):
        # Pick an arbitrary datetime, this should always return False.
        dt = datetime(2011, 9, 1, 2, 30, tzinfo=tz.tzutc())

        self.assertFalse(tz.datetime_ambiguous(dt)) 

def testEqualAmbiguousComparison(self):
        tzname = self._get_tzname('Australia/Sydney')

        with self._gettz_context(tzname):
            SYD0 = self.gettz(tzname)
            SYD1 = self.gettz(tzname)

            t0_u = datetime(2012, 3, 31, 14, 30, tzinfo=tz.tzutc())  # AEST

            t0_syd0 = t0_u.astimezone(SYD0)
            t0_syd1 = t0_u.astimezone(SYD1)

            # This is considered an "inter-zone comparison" because it's an
            # ambiguous datetime.
            self.assertEqual(t0_syd0, t0_syd1)