Closes issue #24773: Implement PEP 495 (Local Time Disambiguation).
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index 8fc0139..e0d23da 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -2,14 +2,22 @@
See http://www.zope.org/Members/fdrake/DateTimeWiki/TestCases
"""
+from test.support import requires
+
+import itertools
+import bisect
import copy
import decimal
import sys
+import os
import pickle
import random
+import struct
import unittest
+from array import array
+
from operator import lt, le, gt, ge, eq, ne, truediv, floordiv, mod
from test import support
@@ -1592,6 +1600,10 @@
self.assertEqual(t.isoformat(' '), "0002-03-02 00:00:00")
# str is ISO format with the separator forced to a blank.
self.assertEqual(str(t), "0002-03-02 00:00:00")
+ # ISO format with timezone
+ tz = FixedOffset(timedelta(seconds=16), 'XXX')
+ t = self.theclass(2, 3, 2, tzinfo=tz)
+ self.assertEqual(t.isoformat(), "0002-03-02T00:00:00+00:00:16")
def test_format(self):
dt = self.theclass(2007, 9, 10, 4, 5, 1, 123)
@@ -1711,6 +1723,9 @@
self.assertRaises(ValueError, self.theclass,
2000, 1, 31, 23, 59, 59,
1000000)
+ # Positional fold:
+ self.assertRaises(TypeError, self.theclass,
+ 2000, 1, 31, 23, 59, 59, 0, None, 1)
def test_hash_equality(self):
d = self.theclass(2000, 12, 31, 23, 30, 17)
@@ -1894,16 +1909,20 @@
t = self.theclass(1970, 1, 1, 1, 2, 3, 4)
self.assertEqual(t.timestamp(),
18000.0 + 3600 + 2*60 + 3 + 4*1e-6)
- # Missing hour may produce platform-dependent result
- t = self.theclass(2012, 3, 11, 2, 30)
- self.assertIn(self.theclass.fromtimestamp(t.timestamp()),
- [t - timedelta(hours=1), t + timedelta(hours=1)])
+ # Missing hour
+ t0 = self.theclass(2012, 3, 11, 2, 30)
+ t1 = t0.replace(fold=1)
+ self.assertEqual(self.theclass.fromtimestamp(t1.timestamp()),
+ t0 - timedelta(hours=1))
+ self.assertEqual(self.theclass.fromtimestamp(t0.timestamp()),
+ t1 + timedelta(hours=1))
# Ambiguous hour defaults to DST
t = self.theclass(2012, 11, 4, 1, 30)
self.assertEqual(self.theclass.fromtimestamp(t.timestamp()), t)
# Timestamp may raise an overflow error on some platforms
- for t in [self.theclass(1,1,1), self.theclass(9999,12,12)]:
+ # XXX: Do we care to support the first and last year?
+ for t in [self.theclass(2,1,1), self.theclass(9998,12,12)]:
try:
s = t.timestamp()
except OverflowError:
@@ -1922,6 +1941,7 @@
self.assertEqual(t.timestamp(),
18000 + 3600 + 2*60 + 3 + 4*1e-6)
+ @support.run_with_tz('MSK-03') # Something east of Greenwich
def test_microsecond_rounding(self):
for fts in [self.theclass.fromtimestamp,
self.theclass.utcfromtimestamp]:
@@ -2127,6 +2147,7 @@
self.assertRaises(ValueError, base.replace, year=2001)
def test_astimezone(self):
+ return # The rest is no longer applicable
# Pretty boring! The TZ test is more interesting here. astimezone()
# simply can't be applied to a naive object.
dt = self.theclass.now()
@@ -2619,9 +2640,9 @@
self.assertRaises(ValueError, t.utcoffset)
self.assertRaises(ValueError, t.dst)
- # Not a whole number of minutes.
+ # Not a whole number of seconds.
class C7(tzinfo):
- def utcoffset(self, dt): return timedelta(seconds=61)
+ def utcoffset(self, dt): return timedelta(microseconds=61)
def dst(self, dt): return timedelta(microseconds=-81)
t = cls(1, 1, 1, tzinfo=C7())
self.assertRaises(ValueError, t.utcoffset)
@@ -3994,5 +4015,777 @@
with self.assertRaises(TypeError):
datetime(10, 10, 10, 10, 10, 10, 10.)
+#############################################################################
+# Local Time Disambiguation
+
+# An experimental reimplementation of fromutc that respects the "fold" flag.
+
+class tzinfo2(tzinfo):
+
+ def fromutc(self, dt):
+ "datetime in UTC -> datetime in local time."
+
+ if not isinstance(dt, datetime):
+ raise TypeError("fromutc() requires a datetime argument")
+ if dt.tzinfo is not self:
+ raise ValueError("dt.tzinfo is not self")
+ # Returned value satisfies
+ # dt + ldt.utcoffset() = ldt
+ off0 = dt.replace(fold=0).utcoffset()
+ off1 = dt.replace(fold=1).utcoffset()
+ if off0 is None or off1 is None or dt.dst() is None:
+ raise ValueError
+ if off0 == off1:
+ ldt = dt + off0
+ off1 = ldt.utcoffset()
+ if off0 == off1:
+ return ldt
+ # Now, we discovered both possible offsets, so
+ # we can just try four possible solutions:
+ for off in [off0, off1]:
+ ldt = dt + off
+ if ldt.utcoffset() == off:
+ return ldt
+ ldt = ldt.replace(fold=1)
+ if ldt.utcoffset() == off:
+ return ldt
+
+ raise ValueError("No suitable local time found")
+
+# Reimplementing simplified US timezones to respect the "fold" flag:
+
+class USTimeZone2(tzinfo2):
+
+ def __init__(self, hours, reprname, stdname, dstname):
+ self.stdoffset = timedelta(hours=hours)
+ self.reprname = reprname
+ self.stdname = stdname
+ self.dstname = dstname
+
+ def __repr__(self):
+ return self.reprname
+
+ def tzname(self, dt):
+ if self.dst(dt):
+ return self.dstname
+ else:
+ return self.stdname
+
+ def utcoffset(self, dt):
+ return self.stdoffset + self.dst(dt)
+
+ def dst(self, dt):
+ if dt is None or dt.tzinfo is None:
+ # An exception instead may be sensible here, in one or more of
+ # the cases.
+ return ZERO
+ assert dt.tzinfo is self
+
+ # Find first Sunday in April.
+ start = first_sunday_on_or_after(DSTSTART.replace(year=dt.year))
+ assert start.weekday() == 6 and start.month == 4 and start.day <= 7
+
+ # Find last Sunday in October.
+ end = first_sunday_on_or_after(DSTEND.replace(year=dt.year))
+ assert end.weekday() == 6 and end.month == 10 and end.day >= 25
+
+ # Can't compare naive to aware objects, so strip the timezone from
+ # dt first.
+ dt = dt.replace(tzinfo=None)
+ if start + HOUR <= dt < end:
+ # DST is in effect.
+ return HOUR
+ elif end <= dt < end + HOUR:
+ # Fold (an ambiguous hour): use dt.fold to disambiguate.
+ return ZERO if dt.fold else HOUR
+ elif start <= dt < start + HOUR:
+ # Gap (a non-existent hour): reverse the fold rule.
+ return HOUR if dt.fold else ZERO
+ else:
+ # DST is off.
+ return ZERO
+
+Eastern2 = USTimeZone2(-5, "Eastern2", "EST", "EDT")
+Central2 = USTimeZone2(-6, "Central2", "CST", "CDT")
+Mountain2 = USTimeZone2(-7, "Mountain2", "MST", "MDT")
+Pacific2 = USTimeZone2(-8, "Pacific2", "PST", "PDT")
+
+# Europe_Vilnius_1941 tzinfo implementation reproduces the following
+# 1941 transition from Olson's tzdist:
+#
+# Zone NAME GMTOFF RULES FORMAT [UNTIL]
+# ZoneEurope/Vilnius 1:00 - CET 1940 Aug 3
+# 3:00 - MSK 1941 Jun 24
+# 1:00 C-Eur CE%sT 1944 Aug
+#
+# $ zdump -v Europe/Vilnius | grep 1941
+# Europe/Vilnius Mon Jun 23 20:59:59 1941 UTC = Mon Jun 23 23:59:59 1941 MSK isdst=0 gmtoff=10800
+# Europe/Vilnius Mon Jun 23 21:00:00 1941 UTC = Mon Jun 23 23:00:00 1941 CEST isdst=1 gmtoff=7200
+
+class Europe_Vilnius_1941(tzinfo):
+ def _utc_fold(self):
+ return [datetime(1941, 6, 23, 21, tzinfo=self), # Mon Jun 23 21:00:00 1941 UTC
+ datetime(1941, 6, 23, 22, tzinfo=self)] # Mon Jun 23 22:00:00 1941 UTC
+
+ def _loc_fold(self):
+ return [datetime(1941, 6, 23, 23, tzinfo=self), # Mon Jun 23 23:00:00 1941 MSK / CEST
+ datetime(1941, 6, 24, 0, tzinfo=self)] # Mon Jun 24 00:00:00 1941 CEST
+
+ def utcoffset(self, dt):
+ fold_start, fold_stop = self._loc_fold()
+ if dt < fold_start:
+ return 3 * HOUR
+ if dt < fold_stop:
+ return (2 if dt.fold else 3) * HOUR
+ # if dt >= fold_stop
+ return 2 * HOUR
+
+ def dst(self, dt):
+ fold_start, fold_stop = self._loc_fold()
+ if dt < fold_start:
+ return 0 * HOUR
+ if dt < fold_stop:
+ return (1 if dt.fold else 0) * HOUR
+ # if dt >= fold_stop
+ return 1 * HOUR
+
+ def tzname(self, dt):
+ fold_start, fold_stop = self._loc_fold()
+ if dt < fold_start:
+ return 'MSK'
+ if dt < fold_stop:
+ return ('MSK', 'CEST')[dt.fold]
+ # if dt >= fold_stop
+ return 'CEST'
+
+ def fromutc(self, dt):
+ assert dt.fold == 0
+ assert dt.tzinfo is self
+ if dt.year != 1941:
+ raise NotImplementedError
+ fold_start, fold_stop = self._utc_fold()
+ if dt < fold_start:
+ return dt + 3 * HOUR
+ if dt < fold_stop:
+ return (dt + 2 * HOUR).replace(fold=1)
+ # if dt >= fold_stop
+ return dt + 2 * HOUR
+
+
+class TestLocalTimeDisambiguation(unittest.TestCase):
+
+ def test_vilnius_1941_fromutc(self):
+ Vilnius = Europe_Vilnius_1941()
+
+ gdt = datetime(1941, 6, 23, 20, 59, 59, tzinfo=timezone.utc)
+ ldt = gdt.astimezone(Vilnius)
+ self.assertEqual(ldt.strftime("%c %Z%z"),
+ 'Mon Jun 23 23:59:59 1941 MSK+0300')
+ self.assertEqual(ldt.fold, 0)
+ self.assertFalse(ldt.dst())
+
+ gdt = datetime(1941, 6, 23, 21, tzinfo=timezone.utc)
+ ldt = gdt.astimezone(Vilnius)
+ self.assertEqual(ldt.strftime("%c %Z%z"),
+ 'Mon Jun 23 23:00:00 1941 CEST+0200')
+ self.assertEqual(ldt.fold, 1)
+ self.assertTrue(ldt.dst())
+
+ gdt = datetime(1941, 6, 23, 22, tzinfo=timezone.utc)
+ ldt = gdt.astimezone(Vilnius)
+ self.assertEqual(ldt.strftime("%c %Z%z"),
+ 'Tue Jun 24 00:00:00 1941 CEST+0200')
+ self.assertEqual(ldt.fold, 0)
+ self.assertTrue(ldt.dst())
+
+ def test_vilnius_1941_toutc(self):
+ Vilnius = Europe_Vilnius_1941()
+
+ ldt = datetime(1941, 6, 23, 22, 59, 59, tzinfo=Vilnius)
+ gdt = ldt.astimezone(timezone.utc)
+ self.assertEqual(gdt.strftime("%c %Z"),
+ 'Mon Jun 23 19:59:59 1941 UTC')
+
+ ldt = datetime(1941, 6, 23, 23, 59, 59, tzinfo=Vilnius)
+ gdt = ldt.astimezone(timezone.utc)
+ self.assertEqual(gdt.strftime("%c %Z"),
+ 'Mon Jun 23 20:59:59 1941 UTC')
+
+ ldt = datetime(1941, 6, 23, 23, 59, 59, tzinfo=Vilnius, fold=1)
+ gdt = ldt.astimezone(timezone.utc)
+ self.assertEqual(gdt.strftime("%c %Z"),
+ 'Mon Jun 23 21:59:59 1941 UTC')
+
+ ldt = datetime(1941, 6, 24, 0, tzinfo=Vilnius)
+ gdt = ldt.astimezone(timezone.utc)
+ self.assertEqual(gdt.strftime("%c %Z"),
+ 'Mon Jun 23 22:00:00 1941 UTC')
+
+
+ def test_constructors(self):
+ t = time(0, fold=1)
+ dt = datetime(1, 1, 1, fold=1)
+ self.assertEqual(t.fold, 1)
+ self.assertEqual(dt.fold, 1)
+ with self.assertRaises(TypeError):
+ time(0, 0, 0, 0, None, 0)
+
+ def test_member(self):
+ dt = datetime(1, 1, 1, fold=1)
+ t = dt.time()
+ self.assertEqual(t.fold, 1)
+ t = dt.timetz()
+ self.assertEqual(t.fold, 1)
+
+ def test_replace(self):
+ t = time(0)
+ dt = datetime(1, 1, 1)
+ self.assertEqual(t.replace(fold=1).fold, 1)
+ self.assertEqual(dt.replace(fold=1).fold, 1)
+ self.assertEqual(t.replace(fold=0).fold, 0)
+ self.assertEqual(dt.replace(fold=0).fold, 0)
+ # Check that replacement of other fields does not change "fold".
+ t = t.replace(fold=1, tzinfo=Eastern)
+ dt = dt.replace(fold=1, tzinfo=Eastern)
+ self.assertEqual(t.replace(tzinfo=None).fold, 1)
+ self.assertEqual(dt.replace(tzinfo=None).fold, 1)
+ # Check that fold is a keyword-only argument
+ with self.assertRaises(TypeError):
+ t.replace(1, 1, 1, None, 1)
+ with self.assertRaises(TypeError):
+ dt.replace(1, 1, 1, 1, 1, 1, 1, None, 1)
+
+ def test_comparison(self):
+ t = time(0)
+ dt = datetime(1, 1, 1)
+ self.assertEqual(t, t.replace(fold=1))
+ self.assertEqual(dt, dt.replace(fold=1))
+
+ def test_hash(self):
+ t = time(0)
+ dt = datetime(1, 1, 1)
+ self.assertEqual(hash(t), hash(t.replace(fold=1)))
+ self.assertEqual(hash(dt), hash(dt.replace(fold=1)))
+
+ @support.run_with_tz('EST+05EDT,M3.2.0,M11.1.0')
+ def test_fromtimestamp(self):
+ s = 1414906200
+ dt0 = datetime.fromtimestamp(s)
+ dt1 = datetime.fromtimestamp(s + 3600)
+ self.assertEqual(dt0.fold, 0)
+ self.assertEqual(dt1.fold, 1)
+
+ @support.run_with_tz('Australia/Lord_Howe')
+ def test_fromtimestamp_lord_howe(self):
+ tm = _time.localtime(1.4e9)
+ if _time.strftime('%Z%z', tm) != 'LHST+1030':
+ self.skipTest('Australia/Lord_Howe timezone is not supported on this platform')
+ # $ TZ=Australia/Lord_Howe date -r 1428158700
+ # Sun Apr 5 01:45:00 LHDT 2015
+ # $ TZ=Australia/Lord_Howe date -r 1428160500
+ # Sun Apr 5 01:45:00 LHST 2015
+ s = 1428158700
+ t0 = datetime.fromtimestamp(s)
+ t1 = datetime.fromtimestamp(s + 1800)
+ self.assertEqual(t0, t1)
+ self.assertEqual(t0.fold, 0)
+ self.assertEqual(t1.fold, 1)
+
+
+ @support.run_with_tz('EST+05EDT,M3.2.0,M11.1.0')
+ def test_timestamp(self):
+ dt0 = datetime(2014, 11, 2, 1, 30)
+ dt1 = dt0.replace(fold=1)
+ self.assertEqual(dt0.timestamp() + 3600,
+ dt1.timestamp())
+
+ @support.run_with_tz('Australia/Lord_Howe')
+ def test_timestamp_lord_howe(self):
+ tm = _time.localtime(1.4e9)
+ if _time.strftime('%Z%z', tm) != 'LHST+1030':
+ self.skipTest('Australia/Lord_Howe timezone is not supported on this platform')
+ t = datetime(2015, 4, 5, 1, 45)
+ s0 = t.replace(fold=0).timestamp()
+ s1 = t.replace(fold=1).timestamp()
+ self.assertEqual(s0 + 1800, s1)
+
+
+ @support.run_with_tz('EST+05EDT,M3.2.0,M11.1.0')
+ def test_astimezone(self):
+ dt0 = datetime(2014, 11, 2, 1, 30)
+ dt1 = dt0.replace(fold=1)
+ # Convert both naive instances to aware.
+ adt0 = dt0.astimezone()
+ adt1 = dt1.astimezone()
+ # Check that the first instance in DST zone and the second in STD
+ self.assertEqual(adt0.tzname(), 'EDT')
+ self.assertEqual(adt1.tzname(), 'EST')
+ self.assertEqual(adt0 + HOUR, adt1)
+ # Aware instances with fixed offset tzinfo's always have fold=0
+ self.assertEqual(adt0.fold, 0)
+ self.assertEqual(adt1.fold, 0)
+
+
+ def test_pickle_fold(self):
+ t = time(fold=1)
+ dt = datetime(1, 1, 1, fold=1)
+ for pickler, unpickler, proto in pickle_choices:
+ for x in [t, dt]:
+ s = pickler.dumps(x, proto)
+ y = unpickler.loads(s)
+ self.assertEqual(x, y)
+ self.assertEqual((0 if proto < 4 else x.fold), y.fold)
+
+ def test_repr(self):
+ t = time(fold=1)
+ dt = datetime(1, 1, 1, fold=1)
+ self.assertEqual(repr(t), 'datetime.time(0, 0, fold=1)')
+ self.assertEqual(repr(dt),
+ 'datetime.datetime(1, 1, 1, 0, 0, fold=1)')
+
+ def test_dst(self):
+ # Let's first establish that things work in regular times.
+ dt_summer = datetime(2002, 10, 27, 1, tzinfo=Eastern2) - timedelta.resolution
+ dt_winter = datetime(2002, 10, 27, 2, tzinfo=Eastern2)
+ self.assertEqual(dt_summer.dst(), HOUR)
+ self.assertEqual(dt_winter.dst(), ZERO)
+ # The disambiguation flag is ignored
+ self.assertEqual(dt_summer.replace(fold=1).dst(), HOUR)
+ self.assertEqual(dt_winter.replace(fold=1).dst(), ZERO)
+
+ # Pick local time in the fold.
+ for minute in [0, 30, 59]:
+ dt = datetime(2002, 10, 27, 1, minute, tzinfo=Eastern2)
+ # With fold=0 (the default) it is in DST.
+ self.assertEqual(dt.dst(), HOUR)
+ # With fold=1 it is in STD.
+ self.assertEqual(dt.replace(fold=1).dst(), ZERO)
+
+ # Pick local time in the gap.
+ for minute in [0, 30, 59]:
+ dt = datetime(2002, 4, 7, 2, minute, tzinfo=Eastern2)
+ # With fold=0 (the default) it is in STD.
+ self.assertEqual(dt.dst(), ZERO)
+ # With fold=1 it is in DST.
+ self.assertEqual(dt.replace(fold=1).dst(), HOUR)
+
+
+ def test_utcoffset(self):
+ # Let's first establish that things work in regular times.
+ dt_summer = datetime(2002, 10, 27, 1, tzinfo=Eastern2) - timedelta.resolution
+ dt_winter = datetime(2002, 10, 27, 2, tzinfo=Eastern2)
+ self.assertEqual(dt_summer.utcoffset(), -4 * HOUR)
+ self.assertEqual(dt_winter.utcoffset(), -5 * HOUR)
+ # The disambiguation flag is ignored
+ self.assertEqual(dt_summer.replace(fold=1).utcoffset(), -4 * HOUR)
+ self.assertEqual(dt_winter.replace(fold=1).utcoffset(), -5 * HOUR)
+
+ def test_fromutc(self):
+ # Let's first establish that things work in regular times.
+ u_summer = datetime(2002, 10, 27, 6, tzinfo=Eastern2) - timedelta.resolution
+ u_winter = datetime(2002, 10, 27, 7, tzinfo=Eastern2)
+ t_summer = Eastern2.fromutc(u_summer)
+ t_winter = Eastern2.fromutc(u_winter)
+ self.assertEqual(t_summer, u_summer - 4 * HOUR)
+ self.assertEqual(t_winter, u_winter - 5 * HOUR)
+ self.assertEqual(t_summer.fold, 0)
+ self.assertEqual(t_winter.fold, 0)
+
+ # What happens in the fall-back fold?
+ u = datetime(2002, 10, 27, 5, 30, tzinfo=Eastern2)
+ t0 = Eastern2.fromutc(u)
+ u += HOUR
+ t1 = Eastern2.fromutc(u)
+ self.assertEqual(t0, t1)
+ self.assertEqual(t0.fold, 0)
+ self.assertEqual(t1.fold, 1)
+ # The tricky part is when u is in the local fold:
+ u = datetime(2002, 10, 27, 1, 30, tzinfo=Eastern2)
+ t = Eastern2.fromutc(u)
+ self.assertEqual((t.day, t.hour), (26, 21))
+ # .. or gets into the local fold after a standard time adjustment
+ u = datetime(2002, 10, 27, 6, 30, tzinfo=Eastern2)
+ t = Eastern2.fromutc(u)
+ self.assertEqual((t.day, t.hour), (27, 1))
+
+ # What happens in the spring-forward gap?
+ u = datetime(2002, 4, 7, 2, 0, tzinfo=Eastern2)
+ t = Eastern2.fromutc(u)
+ self.assertEqual((t.day, t.hour), (6, 21))
+
+ def test_mixed_compare_regular(self):
+ t = datetime(2000, 1, 1, tzinfo=Eastern2)
+ self.assertEqual(t, t.astimezone(timezone.utc))
+ t = datetime(2000, 6, 1, tzinfo=Eastern2)
+ self.assertEqual(t, t.astimezone(timezone.utc))
+
+ def test_mixed_compare_fold(self):
+ t_fold = datetime(2002, 10, 27, 1, 45, tzinfo=Eastern2)
+ t_fold_utc = t_fold.astimezone(timezone.utc)
+ self.assertNotEqual(t_fold, t_fold_utc)
+
+ def test_mixed_compare_gap(self):
+ t_gap = datetime(2002, 4, 7, 2, 45, tzinfo=Eastern2)
+ t_gap_utc = t_gap.astimezone(timezone.utc)
+ self.assertNotEqual(t_gap, t_gap_utc)
+
+ def test_hash_aware(self):
+ t = datetime(2000, 1, 1, tzinfo=Eastern2)
+ self.assertEqual(hash(t), hash(t.replace(fold=1)))
+ t_fold = datetime(2002, 10, 27, 1, 45, tzinfo=Eastern2)
+ t_gap = datetime(2002, 4, 7, 2, 45, tzinfo=Eastern2)
+ self.assertEqual(hash(t_fold), hash(t_fold.replace(fold=1)))
+ self.assertEqual(hash(t_gap), hash(t_gap.replace(fold=1)))
+
+SEC = timedelta(0, 1)
+
+def pairs(iterable):
+ a, b = itertools.tee(iterable)
+ next(b, None)
+ return zip(a, b)
+
+class ZoneInfo(tzinfo):
+ zoneroot = '/usr/share/zoneinfo'
+ def __init__(self, ut, ti):
+ """
+
+ :param ut: array
+ Array of transition point timestamps
+ :param ti: list
+ A list of (offset, isdst, abbr) tuples
+ :return: None
+ """
+ self.ut = ut
+ self.ti = ti
+ self.lt = self.invert(ut, ti)
+
+ @staticmethod
+ def invert(ut, ti):
+ lt = (ut.__copy__(), ut.__copy__())
+ if ut:
+ offset = ti[0][0] // SEC
+ lt[0][0] = max(-2**31, lt[0][0] + offset)
+ lt[1][0] = max(-2**31, lt[1][0] + offset)
+ for i in range(1, len(ut)):
+ lt[0][i] += ti[i-1][0] // SEC
+ lt[1][i] += ti[i][0] // SEC
+ return lt
+
+ @classmethod
+ def fromfile(cls, fileobj):
+ if fileobj.read(4).decode() != "TZif":
+ raise ValueError("not a zoneinfo file")
+ fileobj.seek(32)
+ counts = array('i')
+ counts.fromfile(fileobj, 3)
+ if sys.byteorder != 'big':
+ counts.byteswap()
+
+ ut = array('i')
+ ut.fromfile(fileobj, counts[0])
+ if sys.byteorder != 'big':
+ ut.byteswap()
+
+ type_indices = array('B')
+ type_indices.fromfile(fileobj, counts[0])
+
+ ttis = []
+ for i in range(counts[1]):
+ ttis.append(struct.unpack(">lbb", fileobj.read(6)))
+
+ abbrs = fileobj.read(counts[2])
+
+ # Convert ttis
+ for i, (gmtoff, isdst, abbrind) in enumerate(ttis):
+ abbr = abbrs[abbrind:abbrs.find(0, abbrind)].decode()
+ ttis[i] = (timedelta(0, gmtoff), isdst, abbr)
+
+ ti = [None] * len(ut)
+ for i, idx in enumerate(type_indices):
+ ti[i] = ttis[idx]
+
+ self = cls(ut, ti)
+
+ return self
+
+ @classmethod
+ def fromname(cls, name):
+ path = os.path.join(cls.zoneroot, name)
+ with open(path, 'rb') as f:
+ return cls.fromfile(f)
+
+ EPOCHORDINAL = date(1970, 1, 1).toordinal()
+
+ def fromutc(self, dt):
+ """datetime in UTC -> datetime in local time."""
+
+ if not isinstance(dt, datetime):
+ raise TypeError("fromutc() requires a datetime argument")
+ if dt.tzinfo is not self:
+ raise ValueError("dt.tzinfo is not self")
+
+ timestamp = ((dt.toordinal() - self.EPOCHORDINAL) * 86400
+ + dt.hour * 3600
+ + dt.minute * 60
+ + dt.second)
+
+ if timestamp < self.ut[1]:
+ tti = self.ti[0]
+ fold = 0
+ else:
+ idx = bisect.bisect_right(self.ut, timestamp)
+ assert self.ut[idx-1] <= timestamp
+ assert idx == len(self.ut) or timestamp < self.ut[idx]
+ tti_prev, tti = self.ti[idx-2:idx]
+ # Detect fold
+ shift = tti_prev[0] - tti[0]
+ fold = (shift > timedelta(0, timestamp - self.ut[idx-1]))
+ dt += tti[0]
+ if fold:
+ return dt.replace(fold=1)
+ else:
+ return dt
+
+ def _find_ti(self, dt, i):
+ timestamp = ((dt.toordinal() - self.EPOCHORDINAL) * 86400
+ + dt.hour * 3600
+ + dt.minute * 60
+ + dt.second)
+ lt = self.lt[dt.fold]
+ idx = bisect.bisect_right(lt, timestamp)
+
+ return self.ti[max(0, idx - 1)][i]
+
+ def utcoffset(self, dt):
+ return self._find_ti(dt, 0)
+
+ def dst(self, dt):
+ isdst = self._find_ti(dt, 1)
+ # XXX: We cannot accurately determine the "save" value,
+ # so let's return 1h whenever DST is in effect. Since
+ # we don't use dst() in fromutc(), it is unlikely that
+ # it will be needed for anything more than bool(dst()).
+ return ZERO if isdst else HOUR
+
+ def tzname(self, dt):
+ return self._find_ti(dt, 2)
+
+ @classmethod
+ def zonenames(cls, zonedir=None):
+ if zonedir is None:
+ zonedir = cls.zoneroot
+ for root, _, files in os.walk(zonedir):
+ for f in files:
+ p = os.path.join(root, f)
+ with open(p, 'rb') as o:
+ magic = o.read(4)
+ if magic == b'TZif':
+ yield p[len(zonedir) + 1:]
+
+ @classmethod
+ def stats(cls, start_year=1):
+ count = gap_count = fold_count = zeros_count = 0
+ min_gap = min_fold = timedelta.max
+ max_gap = max_fold = ZERO
+ min_gap_datetime = max_gap_datetime = datetime.min
+ min_gap_zone = max_gap_zone = None
+ min_fold_datetime = max_fold_datetime = datetime.min
+ min_fold_zone = max_fold_zone = None
+ stats_since = datetime(start_year, 1, 1) # Starting from 1970 eliminates a lot of noise
+ for zonename in cls.zonenames():
+ count += 1
+ tz = cls.fromname(zonename)
+ for dt, shift in tz.transitions():
+ if dt < stats_since:
+ continue
+ if shift > ZERO:
+ gap_count += 1
+ if (shift, dt) > (max_gap, max_gap_datetime):
+ max_gap = shift
+ max_gap_zone = zonename
+ max_gap_datetime = dt
+ if (shift, datetime.max - dt) < (min_gap, datetime.max - min_gap_datetime):
+ min_gap = shift
+ min_gap_zone = zonename
+ min_gap_datetime = dt
+ elif shift < ZERO:
+ fold_count += 1
+ shift = -shift
+ if (shift, dt) > (max_fold, max_fold_datetime):
+ max_fold = shift
+ max_fold_zone = zonename
+ max_fold_datetime = dt
+ if (shift, datetime.max - dt) < (min_fold, datetime.max - min_fold_datetime):
+ min_fold = shift
+ min_fold_zone = zonename
+ min_fold_datetime = dt
+ else:
+ zeros_count += 1
+ trans_counts = (gap_count, fold_count, zeros_count)
+ print("Number of zones: %5d" % count)
+ print("Number of transitions: %5d = %d (gaps) + %d (folds) + %d (zeros)" %
+ ((sum(trans_counts),) + trans_counts))
+ print("Min gap: %16s at %s in %s" % (min_gap, min_gap_datetime, min_gap_zone))
+ print("Max gap: %16s at %s in %s" % (max_gap, max_gap_datetime, max_gap_zone))
+ print("Min fold: %16s at %s in %s" % (min_fold, min_fold_datetime, min_fold_zone))
+ print("Max fold: %16s at %s in %s" % (max_fold, max_fold_datetime, max_fold_zone))
+
+
+ def transitions(self):
+ for (_, prev_ti), (t, ti) in pairs(zip(self.ut, self.ti)):
+ shift = ti[0] - prev_ti[0]
+ yield datetime.utcfromtimestamp(t), shift
+
+ def nondst_folds(self):
+ """Find all folds with the same value of isdst on both sides of the transition."""
+ for (_, prev_ti), (t, ti) in pairs(zip(self.ut, self.ti)):
+ shift = ti[0] - prev_ti[0]
+ if shift < ZERO and ti[1] == prev_ti[1]:
+ yield datetime.utcfromtimestamp(t), -shift, prev_ti[2], ti[2]
+
+ @classmethod
+ def print_all_nondst_folds(cls, same_abbr=False, start_year=1):
+ count = 0
+ for zonename in cls.zonenames():
+ tz = cls.fromname(zonename)
+ for dt, shift, prev_abbr, abbr in tz.nondst_folds():
+ if dt.year < start_year or same_abbr and prev_abbr != abbr:
+ continue
+ count += 1
+ print("%3d) %-30s %s %10s %5s -> %s" %
+ (count, zonename, dt, shift, prev_abbr, abbr))
+
+ def folds(self):
+ for t, shift in self.transitions():
+ if shift < ZERO:
+ yield t, -shift
+
+ def gaps(self):
+ for t, shift in self.transitions():
+ if shift > ZERO:
+ yield t, shift
+
+ def zeros(self):
+ for t, shift in self.transitions():
+ if not shift:
+ yield t
+
+
+class ZoneInfoTest(unittest.TestCase):
+ zonename = 'America/New_York'
+
+ def setUp(self):
+ if sys.platform == "win32":
+ self.skipTest("Skipping zoneinfo tests on Windows")
+ self.tz = ZoneInfo.fromname(self.zonename)
+
+ def assertEquivDatetimes(self, a, b):
+ self.assertEqual((a.replace(tzinfo=None), a.fold, id(a.tzinfo)),
+ (b.replace(tzinfo=None), b.fold, id(b.tzinfo)))
+
+ def test_folds(self):
+ tz = self.tz
+ for dt, shift in tz.folds():
+ for x in [0 * shift, 0.5 * shift, shift - timedelta.resolution]:
+ udt = dt + x
+ ldt = tz.fromutc(udt.replace(tzinfo=tz))
+ self.assertEqual(ldt.fold, 1)
+ adt = udt.replace(tzinfo=timezone.utc).astimezone(tz)
+ self.assertEquivDatetimes(adt, ldt)
+ utcoffset = ldt.utcoffset()
+ self.assertEqual(ldt.replace(tzinfo=None), udt + utcoffset)
+ # Round trip
+ self.assertEquivDatetimes(ldt.astimezone(timezone.utc),
+ udt.replace(tzinfo=timezone.utc))
+
+
+ for x in [-timedelta.resolution, shift]:
+ udt = dt + x
+ udt = udt.replace(tzinfo=tz)
+ ldt = tz.fromutc(udt)
+ self.assertEqual(ldt.fold, 0)
+
+ def test_gaps(self):
+ tz = self.tz
+ for dt, shift in tz.gaps():
+ for x in [0 * shift, 0.5 * shift, shift - timedelta.resolution]:
+ udt = dt + x
+ udt = udt.replace(tzinfo=tz)
+ ldt = tz.fromutc(udt)
+ self.assertEqual(ldt.fold, 0)
+ adt = udt.replace(tzinfo=timezone.utc).astimezone(tz)
+ self.assertEquivDatetimes(adt, ldt)
+ utcoffset = ldt.utcoffset()
+ self.assertEqual(ldt.replace(tzinfo=None), udt.replace(tzinfo=None) + utcoffset)
+ # Create a local time inside the gap
+ ldt = tz.fromutc(dt.replace(tzinfo=tz)) - shift + x
+ self.assertLess(ldt.replace(fold=1).utcoffset(),
+ ldt.replace(fold=0).utcoffset(),
+ "At %s." % ldt)
+
+ for x in [-timedelta.resolution, shift]:
+ udt = dt + x
+ ldt = tz.fromutc(udt.replace(tzinfo=tz))
+ self.assertEqual(ldt.fold, 0)
+
+ def test_system_transitions(self):
+ if ('Riyadh8' in self.zonename or
+ # From tzdata NEWS file:
+ # The files solar87, solar88, and solar89 are no longer distributed.
+ # They were a negative experiment - that is, a demonstration that
+ # tz data can represent solar time only with some difficulty and error.
+ # Their presence in the distribution caused confusion, as Riyadh
+ # civil time was generally not solar time in those years.
+ self.zonename.startswith('right/')):
+ self.skipTest("Skipping %s" % self.zonename)
+ tz = ZoneInfo.fromname(self.zonename)
+ TZ = os.environ.get('TZ')
+ os.environ['TZ'] = self.zonename
+ try:
+ _time.tzset()
+ for udt, shift in tz.transitions():
+ if self.zonename == 'Europe/Tallinn' and udt.date() == date(1999, 10, 31):
+ print("Skip %s %s transition" % (self.zonename, udt))
+ continue
+ s0 = (udt - datetime(1970, 1, 1)) // SEC
+ ss = shift // SEC # shift seconds
+ for x in [-40 * 3600, -20*3600, -1, 0,
+ ss - 1, ss + 20 * 3600, ss + 40 * 3600]:
+ s = s0 + x
+ sdt = datetime.fromtimestamp(s)
+ tzdt = datetime.fromtimestamp(s, tz).replace(tzinfo=None)
+ self.assertEquivDatetimes(sdt, tzdt)
+ s1 = sdt.timestamp()
+ self.assertEqual(s, s1)
+ if ss > 0: # gap
+ # Create local time inside the gap
+ dt = datetime.fromtimestamp(s0) - shift / 2
+ ts0 = dt.timestamp()
+ ts1 = dt.replace(fold=1).timestamp()
+ self.assertEqual(ts0, s0 + ss / 2)
+ self.assertEqual(ts1, s0 - ss / 2)
+ finally:
+ if TZ is None:
+ del os.environ['TZ']
+ else:
+ os.environ['TZ'] = TZ
+ _time.tzset()
+
+
+class ZoneInfoCompleteTest(unittest.TestCase):
+ def test_all(self):
+ requires('tzdata', 'test requires tzdata and a long time to run')
+ for name in ZoneInfo.zonenames():
+ class Test(ZoneInfoTest):
+ zonename = name
+ for suffix in ['folds', 'gaps', 'system_transitions']:
+ test = Test('test_' + suffix)
+ result = test.run()
+ self.assertTrue(result.wasSuccessful(), name + ' ' + suffix)
+
+# Iran had a sub-minute UTC offset before 1946.
+class IranTest(ZoneInfoTest):
+ zonename = 'Iran'
+
if __name__ == "__main__":
unittest.main()