Drop support for pytz

Replace pytz with zoneinfo which is part of the Python standard library
since Python 3.9.

Bug-Ubuntu: https://launchpad.net/bugs/2101044

Author: bdrung

README.rst

@@ -109,11 +109,11 @@ About DST
 =========
 Be sure to init your croniter instance with a TZ aware datetime for this to work!
 
-Example using pytz::
+Example using zoneinfo::
 
-    >>> import pytz
-    >>> tz = pytz.timezone("Europe/Paris")
-    >>> local_date = tz.localize(datetime(2017, 3, 26))
+    >>> import zoneinfo
+    >>> tz = zoneinfo.ZoneInfo("Europe/Paris")
+    >>> local_date = datetime(2017, 3, 26, tzinfo=tz)
     >>> val = croniter('0 0 * * *', local_date).get_next(datetime)
 
 Example using python_dateutil::

pyproject.toml

@@ -30,7 +30,6 @@ classifiers = [
 ]
 dependencies = [
   "python_dateutil",
-  "pytz>2021.1",
 ]
 dynamic = ["readme"]
 

src/croniter/croniter.py

@@ -12,9 +12,6 @@
 import traceback as _traceback
 from time import time
 
-# as pytz is optional in thirdparty libs but we need it for good support under
-# python2, just test that it's well installed
-import pytz  # noqa
 from dateutil.relativedelta import relativedelta
 from dateutil.tz import tzutc
 
@@ -63,11 +60,7 @@ def is_32bit():
     OrderedDict = dict  # py26 degraded mode, expanders order will not be immutable
 
 
-try:
-    # py3 recent
-    UTC_DT = datetime.timezone.utc
-except AttributeError:
-    UTC_DT = pytz.utc
+UTC_DT = datetime.timezone.utc
 EPOCH = datetime.datetime.fromtimestamp(0, UTC_DT)
 
 # fmt: off

src/croniter/tests/test_croniter.py

@@ -5,12 +5,12 @@
 except ImportError:
     import unittest
 
+import zoneinfo
 from datetime import datetime, timedelta
 from functools import partial
 from time import sleep
 
 import dateutil.tz
-import pytz
 
 from croniter import (
     CroniterBadCronError,
@@ -731,10 +731,11 @@ def testTimezone(self):
         n1 = itr.get_next(datetime)
         self.assertEqual(n1.tzinfo, None)
 
-        tokyo = pytz.timezone("Asia/Tokyo")
-        itr2 = croniter("* * * * *", tokyo.localize(base))
+        tokyo = zoneinfo.ZoneInfo("Asia/Tokyo")
+        start = datetime(2013, 3, 4, 12, 15, tzinfo=tokyo)
+        itr2 = croniter("* * * * *", start)
         n2 = itr2.get_next(datetime)
-        self.assertEqual(n2.tzinfo.zone, "Asia/Tokyo")
+        self.assertEqual(n2.tzinfo.key, "Asia/Tokyo")
 
     def testTimezoneDateutil(self):
         tokyo = dateutil.tz.gettz("Asia/Tokyo")
@@ -757,7 +758,7 @@ def assertScheduleTimezone(self, callback, expected_schedule):
             self.assertEqual(expected_offset, d.utcoffset().total_seconds())
 
     def testTimezoneWinterTime(self):
-        tz = pytz.timezone("Europe/Athens")
+        tz = zoneinfo.ZoneInfo("Europe/Athens")
 
         expected_schedule = [
             (datetime(2013, 10, 27, 2, 30, 0), 10800),
@@ -769,16 +770,16 @@ def testTimezoneWinterTime(self):
             (datetime(2013, 10, 27, 4, 30, 0), 7200),
         ]
 
-        start = datetime(2013, 10, 27, 2, 0, 0)
-        ct = croniter("*/30 * * * *", tz.localize(start))
+        start = datetime(2013, 10, 27, 2, 0, 0, tzinfo=tz)
+        ct = croniter("*/30 * * * *", start)
         self.assertScheduleTimezone(lambda: ct.get_next(datetime), expected_schedule)
 
-        start = datetime(2013, 10, 27, 5, 0, 0)
-        ct = croniter("*/30 * * * *", tz.localize(start))
+        start = datetime(2013, 10, 27, 5, 0, 0, tzinfo=tz)
+        ct = croniter("*/30 * * * *", start)
         self.assertScheduleTimezone(lambda: ct.get_prev(datetime), reversed(expected_schedule))
 
     def testTimezoneSummerTime(self):
-        tz = pytz.timezone("Europe/Athens")
+        tz = zoneinfo.ZoneInfo("Europe/Athens")
 
         expected_schedule = [
             (datetime(2013, 3, 31, 1, 30, 0), 7200),
@@ -788,12 +789,12 @@ def testTimezoneSummerTime(self):
             (datetime(2013, 3, 31, 4, 30, 0), 10800),
         ]
 
-        start = datetime(2013, 3, 31, 1, 0, 0)
-        ct = croniter("*/30 * * * *", tz.localize(start))
+        start = datetime(2013, 3, 31, 1, 0, 0, tzinfo=tz)
+        ct = croniter("*/30 * * * *", start)
         self.assertScheduleTimezone(lambda: ct.get_next(datetime), expected_schedule)
 
-        start = datetime(2013, 3, 31, 5, 0, 0)
-        ct = croniter("*/30 * * * *", tz.localize(start))
+        start = datetime(2013, 3, 31, 5, 0, 0, tzinfo=tz)
+        ct = croniter("*/30 * * * *", start)
         self.assertScheduleTimezone(lambda: ct.get_prev(datetime), reversed(expected_schedule))
 
     def test_std_dst(self):
@@ -803,41 +804,41 @@ def test_std_dst(self):
         This fixes https://github.com/taichino/croniter/issues/82
 
         """
-        tz = pytz.timezone("Europe/Warsaw")
+        tz = zoneinfo.ZoneInfo("Europe/Warsaw")
         # -> 2017-03-26 01:59+1:00 -> 03:00+2:00
-        local_date = tz.localize(datetime(2017, 3, 26))
+        local_date = datetime(2017, 3, 26, tzinfo=tz)
         val = croniter("0 0 * * *", local_date).get_next(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 3, 27)))
+        self.assertEqual(val, datetime(2017, 3, 27, tzinfo=tz))
         #
-        local_date = tz.localize(datetime(2017, 3, 26, 1))
+        local_date = datetime(2017, 3, 26, 1, tzinfo=tz)
         cr = croniter("0 * * * *", local_date)
         val = cr.get_next(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 3, 26, 3)))
+        self.assertEqual(val, datetime(2017, 3, 26, 3, tzinfo=tz))
         val = cr.get_current(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 3, 26, 3)))
+        self.assertEqual(val, datetime(2017, 3, 26, 3, tzinfo=tz))
 
         # -> 2017-10-29 02:59+2:00 -> 02:00+1:00
-        local_date = tz.localize(datetime(2017, 10, 29))
+        local_date = datetime(2017, 10, 29, tzinfo=tz)
         val = croniter("0 0 * * *", local_date).get_next(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 10, 30)))
-        local_date = tz.localize(datetime(2017, 10, 29, 1, 59))
+        self.assertEqual(val, datetime(2017, 10, 30, tzinfo=tz))
+        local_date = datetime(2017, 10, 29, 1, 59, tzinfo=tz)
         val = croniter("0 * * * *", local_date).get_next(datetime)
         self.assertEqual(
             val.replace(tzinfo=None),
-            tz.localize(datetime(2017, 10, 29, 2)).replace(tzinfo=None),
+            datetime(2017, 10, 29, 2, tzinfo=tz).replace(tzinfo=None),
         )
-        local_date = tz.localize(datetime(2017, 10, 29, 2))
+        local_date = datetime(2017, 10, 29, 2, tzinfo=tz)
         val = croniter("0 * * * *", local_date).get_next(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 10, 29, 3)))
-        local_date = tz.localize(datetime(2017, 10, 29, 3))
+        self.assertEqual(val, datetime(2017, 10, 29, 3, tzinfo=tz))
+        local_date = datetime(2017, 10, 29, 3, tzinfo=tz)
         val = croniter("0 * * * *", local_date).get_next(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 10, 29, 4)))
-        local_date = tz.localize(datetime(2017, 10, 29, 4))
+        self.assertEqual(val, datetime(2017, 10, 29, 4, tzinfo=tz))
+        local_date = datetime(2017, 10, 29, 4, tzinfo=tz)
         val = croniter("0 * * * *", local_date).get_next(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 10, 29, 5)))
-        local_date = tz.localize(datetime(2017, 10, 29, 5))
+        self.assertEqual(val, datetime(2017, 10, 29, 5, tzinfo=tz))
+        local_date = datetime(2017, 10, 29, 5, tzinfo=tz)
         val = croniter("0 * * * *", local_date).get_next(datetime)
-        self.assertEqual(val, tz.localize(datetime(2017, 10, 29, 6)))
+        self.assertEqual(val, datetime(2017, 10, 29, 6, tzinfo=tz))
 
     def test_std_dst2(self):
         """
@@ -848,24 +849,24 @@ def test_std_dst2(self):
         São Paulo, Brazil: 18/02/2018 00:00 -> 17/02/2018 23:00
 
         """
-        tz = pytz.timezone("America/Sao_Paulo")
+        tz = zoneinfo.ZoneInfo("America/Sao_Paulo")
         local_dates = [
             # 17-22: 00 -> 18-00:00
-            (tz.localize(datetime(2018, 2, 17, 21, 0, 0)), "2018-02-18 00:00:00-03:00"),
+            (datetime(2018, 2, 17, 21, 0, 0, tzinfo=tz), "2018-02-18 00:00:00-03:00"),
             # 17-23: 00 -> 18-00:00
-            (tz.localize(datetime(2018, 2, 17, 22, 0, 0)), "2018-02-18 00:00:00-03:00"),
+            (datetime(2018, 2, 17, 22, 0, 0, tzinfo=tz), "2018-02-18 00:00:00-03:00"),
             # 17-23: 00 -> 18-00:00
-            (tz.localize(datetime(2018, 2, 17, 23, 0, 0)), "2018-02-18 00:00:00-03:00"),
+            (datetime(2018, 2, 17, 23, 0, 0, tzinfo=tz), "2018-02-18 00:00:00-03:00"),
             # 18-00: 00 -> 19-00:00
-            (tz.localize(datetime(2018, 2, 18, 0, 0, 0)), "2018-02-19 00:00:00-03:00"),
+            (datetime(2018, 2, 18, 0, 0, 0, tzinfo=tz), "2018-02-19 00:00:00-03:00"),
             # 17-22: 00 -> 18-00:00
-            (tz.localize(datetime(2018, 2, 17, 21, 5, 0)), "2018-02-18 00:00:00-03:00"),
+            (datetime(2018, 2, 17, 21, 5, 0, tzinfo=tz), "2018-02-18 00:00:00-03:00"),
             # 17-23: 00 -> 18-00:00
-            (tz.localize(datetime(2018, 2, 17, 22, 5, 0)), "2018-02-18 00:00:00-03:00"),
+            (datetime(2018, 2, 17, 22, 5, 0, tzinfo=tz), "2018-02-18 00:00:00-03:00"),
             # 17-23: 00 -> 18-00:00
-            (tz.localize(datetime(2018, 2, 17, 23, 5, 0)), "2018-02-18 00:00:00-03:00"),
+            (datetime(2018, 2, 17, 23, 5, 0, tzinfo=tz), "2018-02-18 00:00:00-03:00"),
             # 18-00: 00 -> 19-00:00
-            (tz.localize(datetime(2018, 2, 18, 0, 5, 0)), "2018-02-19 00:00:00-03:00"),
+            (datetime(2018, 2, 18, 0, 5, 0, tzinfo=tz), "2018-02-19 00:00:00-03:00"),
         ]
         ret1 = [croniter("0 0 * * *", d[0]).get_next(datetime) for d in local_dates]
         sret1 = ["{0}".format(d) for d in ret1]
@@ -882,15 +883,15 @@ def test_std_dst3(self):
 
         """
 
-        tz = pytz.timezone("Australia/Adelaide")
+        tz = zoneinfo.ZoneInfo("Australia/Adelaide")
 
-        schedule = croniter("0 0 24 * *", tz.localize(datetime(2020, 4, 15)))
+        schedule = croniter("0 0 24 * *", datetime(2020, 4, 15, tzinfo=tz))
         val1 = schedule.get_prev(datetime)
-        dt1 = tz.localize(datetime(2020, 3, 24))
+        dt1 = datetime(2020, 3, 24, tzinfo=tz)
         self.assertEqual(val1, dt1)
 
         val2 = schedule.get_next(datetime)
-        dt2 = tz.localize(datetime(2020, 4, 24))
+        dt2 = datetime(2020, 4, 24, tzinfo=tz)
         self.assertEqual(val2, dt2)
 
     def test_error_alpha_cron(self):
@@ -1178,7 +1179,7 @@ def test_match_range(self):
         )
 
     def test_dst_issue90_st31ny(self):
-        tz = pytz.timezone("Europe/Paris")
+        tz = zoneinfo.ZoneInfo("Europe/Paris")
         now = datetime(2020, 3, 29, 1, 59, 55, tzinfo=tz)
         it = croniter("1 2 * * *", now)
         #
@@ -1243,8 +1244,8 @@ def test_dst_issue90_st31ny(self):
         )
 
     def test_dst_iter(self):
-        tz = pytz.timezone("Asia/Hebron")
-        now = datetime(2022, 3, 26, 0, 0, 0, tzinfo=tz)
+        tz = zoneinfo.ZoneInfo("Asia/Hebron")
+        now = datetime(2022, 3, 25, 12, 0, 0, tzinfo=tz)
         it = croniter("0 0 * * *", now)
         ret = [
             it.get_next(datetime).isoformat(),
@@ -1255,7 +1256,7 @@ def test_dst_iter(self):
             ret,
             [
                 "2022-03-26T00:00:00+02:00",
-                "2022-03-27T01:00:00+03:00",
+                "2022-03-27T00:00:00+02:00",
                 "2022-03-28T00:00:00+03:00",
             ],
         )
@@ -1770,15 +1771,15 @@ def test_issue_k6(self):
         self.assertRaises(CroniterBadCronError, croniter, "0 0 0 1 0")
 
     def test_issue_k11(self):
-        now = pytz.timezone("America/New_York").localize(datetime(2019, 1, 14, 11, 0, 59))
+        now = datetime(2019, 1, 14, 11, 0, 59, tzinfo=zoneinfo.ZoneInfo("America/New_York"))
         nextnow = croniter("* * * * * ").next(datetime, start_time=now)
         nextnow2 = croniter("* * * * * ", now).next(datetime)
         for nt in nextnow, nextnow2:
-            self.assertEqual(nt.tzinfo.zone, "America/New_York")
+            self.assertEqual(nt.tzinfo.str, "America/New_York")
             self.assertEqual(int(croniter._datetime_to_timestamp(nt)), 1547481660)
 
     def test_issue_k12(self):
-        tz = pytz.timezone("Europe/Athens")
+        tz = zoneinfo.ZoneInfo("Europe/Athens")
         base = datetime(2010, 1, 23, 12, 18, tzinfo=tz)
         itr = croniter("* * * * *")
         itr.set_current(start_time=base)

src/croniter/tests/test_croniter_range.py

@@ -2,10 +2,9 @@
 # -*- coding: utf-8 -*-
 
 import unittest
+import zoneinfo
 from datetime import datetime, timedelta
 
-import pytz
-
 from croniter import CroniterBadCronError, CroniterBadDateError, CroniterBadTypeRangeError, croniter, croniter_range
 from croniter.tests import base
 
@@ -81,30 +80,26 @@ def test_input_type_exceptions(self):
             list(croniter_range(f_start1, dt_stop1, "0 * * * *"))
 
     def test_timezone_dst(self):
-        """Test across DST transition, which technically is a timzone change."""
-        tz = pytz.timezone("America/New_York")
-        start = tz.localize(datetime(2020, 10, 30))
-        stop = tz.localize(datetime(2020, 11, 10))
+        """Test across DST transition."""
+        tz = zoneinfo.ZoneInfo("America/New_York")
+        start = datetime(2020, 10, 30, tzinfo=tz)
+        stop = datetime(2020, 11, 10, tzinfo=tz)
         res = list(croniter_range(start, stop, "0 0 * * *"))
-        self.assertNotEqual(res[0].tzinfo, res[-1].tzinfo)
+        self.assertNotEqual(res[0].dst(), res[-1].dst())
         self.assertEqual(len(res), 12)
 
     def test_extra_hour_day_prio(self):
-        def datetime_tz(*args, **kw):
-            """Defined this in another branch.  single-use-version"""
-            tzinfo = kw.pop("tzinfo")
-            return tzinfo.localize(datetime(*args))
-
-        tz = pytz.timezone("America/New_York")
+        """America/New_York sprang forward from 2 am to 3 am on 2020-03-08."""
+        tz = zoneinfo.ZoneInfo("America/New_York")
         cron = "0 3 * * *"
-        start = datetime_tz(2020, 3, 7, tzinfo=tz)
-        end = datetime_tz(2020, 3, 11, tzinfo=tz)
+        start = datetime(2020, 3, 7, tzinfo=tz)
+        end = datetime(2020, 3, 11, tzinfo=tz)
         ret = [i.isoformat() for i in croniter_range(start, end, cron)]
         self.assertEqual(
             ret,
             [
                 "2020-03-07T03:00:00-05:00",
-                "2020-03-08T03:00:00-04:00",
+                "2020-03-08T02:00:00-05:00",  # == 2020-03-08T03:00:00-04:00
                 "2020-03-09T03:00:00-04:00",
                 "2020-03-10T03:00:00-04:00",
             ],

src/croniter/tests/test_croniter_speed.py

@@ -9,11 +9,10 @@
 
 import os
 import sys
+import zoneinfo
 from datetime import datetime
 from timeit import Timer
 
-import pytz
-
 from croniter import cron_m, croniter
 from croniter.tests import base
 
@@ -91,7 +90,7 @@ def run_long_test(self, iterations=1):
             itr.get_prev(datetime)
 
         # dst regression test
-        tz = pytz.timezone("Europe/Bucharest")
+        tz = zoneinfo.ZoneInfo("Europe/Bucharest")
         offsets = set()
         dst_cron = "15 0,3 * 3 *"
         dst_iters = int(2 * 31 * (iterations / 40))