Replace pytz and tzlocal by zoneinfo

Requires Python 3.9

Author: jspricke

docs/index.rst

@@ -305,15 +305,15 @@ Dealing with dates and time
 ---------------------------
 
 Any timestamp-like attributes of the tasks are converted to timezone-aware
-datetime objects. To achieve this, Tasklib leverages ``pytz`` Python module,
+datetime objects. To achieve this, Tasklib leverages ``zoneinfo`` Python module,
 which brings the Olsen timezone database to Python.
 
 This shields you from annoying details of Daylight Saving Time shifts
 or conversion between different timezones. For example, to list all the
 tasks which are due midnight if you're currently in Berlin:
 
-    >>> myzone = pytz.timezone('Europe/Berlin')
-    >>> midnight = myzone.localize(datetime(2015,2,2,0,0,0))
+    >>> myzone = zoneinfo.ZoneInfo('Europe/Berlin')
+    >>> midnight = datetime(2015,2,2,0,0,0,tzinfo=myzone)
     >>> tw.tasks.filter(due__before=midnight)
 
 However, this is still a little bit tedious. That's why TaskWarrior object
@@ -360,7 +360,7 @@ to localize the naive value first:
 
     >>> from datetime import datetime
     >>> from tasklib.task import local_zone
-    >>> now = local_zone.localize(datetime.now())
+    >>> now = datetime.now().replace(tzinfo=local_zone)
     >>> t['due'] = now
     >>> now
     datetime.datetime(2015, 2, 1, 19, 44, 4, 770001, tzinfo=<DstTzInfo 'Europe/Berlin' CET+1:00:00 STD>)
@@ -370,12 +370,12 @@ to localize the naive value first:
 Also, note that it does not matter whether the timezone aware datetime objects
 are set in the same timezone:
 
-    >>> import pytz
+    >>> import zoneinfo
     >>> t['due']
     datetime.datetime(2015, 2, 1, 19, 44, 4, 770001, tzinfo=<DstTzInfo 'Europe/Berlin' CET+1:00:00 STD>)
-    >>> now.astimezone(pytz.utc)
+    >>> now.astimezone(zoneinfo.ZoneInfo('UTC'))
     datetime.datetime(2015, 2, 1, 18, 44, 4, 770001, tzinfo=<UTC>)
-    >>> t['due'] == now.astimezone(pytz.utc)
+    >>> t['due'] == now.astimezone(zoneinfo.ZoneInfo('UTC'))
     True
 
 *Note*: Following behaviour is available only for TaskWarrior >= 2.4.0.

setup.py

@@ -1,7 +1,5 @@
 from setuptools import setup, find_packages
 
-install_requirements = ['pytz', 'tzlocal']
-
 version = '2.4.3'
 
 setup(
@@ -17,7 +15,6 @@
     packages=find_packages(),
     include_package_data=True,
     test_suite='tasklib.tests',
-    install_requires=install_requirements,
     classifiers=[
         'Development Status :: 6 - Mature',
         'Programming Language :: Python',

tasklib/backends.py

@@ -225,7 +225,7 @@ def convert_datetime_string(self, value):
         args = value.split()
         result = self.execute_command(['calc'] + args)
         naive = datetime.datetime.strptime(result[0], DATE_FORMAT_CALC)
-        localized = local_zone.localize(naive)
+        localized = naive.replace(tzinfo=local_zone)
         return localized
 
     @property

tasklib/serializing.py

@@ -1,14 +1,13 @@
 import datetime
 import importlib
 import json
-import pytz
-import tzlocal
+from zoneinfo import ZoneInfo
 
 
 from .lazy import LazyUUIDTaskSet, LazyUUIDTask
 
 DATE_FORMAT = '%Y%m%dT%H%M%SZ'
-local_zone = pytz.timezone(str(tzlocal.get_localzone()))
+local_zone = ZoneInfo('localtime')
 
 
 class SerializingObject(object):
@@ -73,7 +72,7 @@ def timestamp_serializer(self, date):
 
         # Any serialized timestamp should be localized, we need to
         # convert to UTC before converting to string (DATE_FORMAT uses UTC)
-        date = date.astimezone(pytz.utc)
+        date = date.astimezone(ZoneInfo('UTC'))
 
         return date.strftime(DATE_FORMAT)
 
@@ -83,7 +82,7 @@ def timestamp_deserializer(self, date_str):
 
         # Return timestamp localized in the local zone
         naive_timestamp = datetime.datetime.strptime(date_str, DATE_FORMAT)
-        localized_timestamp = pytz.utc.localize(naive_timestamp)
+        localized_timestamp = naive_timestamp.replace(tzinfo=ZoneInfo('UTC'))
         return localized_timestamp.astimezone(local_zone)
 
     def serialize_entry(self, value):
@@ -226,11 +225,11 @@ def datetime_normalizer(self, value):
         ):
             # Convert to local midnight
             value_full = datetime.datetime.combine(value, datetime.time.min)
-            localized = local_zone.localize(value_full)
+            localized = value_full.replace(tzinfo=local_zone)
         elif isinstance(value, datetime.datetime):
             if value.tzinfo is None:
                 # Convert to localized datetime object
-                localized = local_zone.localize(value)
+                localized = value.replace(tzinfo=local_zone)
             else:
                 # If the value is already localized, there is no need to change
                 # time zone at this point. Also None is a valid value too.

tasklib/task.py

@@ -299,7 +299,7 @@ def waiting(self):
         if not self['wait']:
             return False
 
-        return self['wait'] > local_zone.localize(datetime.datetime.now())
+        return self['wait'] > datetime.datetime.now().replace(tzinfo=local_zone)
 
     @property
     def pending(self):

tasklib/tests.py

@@ -5,12 +5,12 @@
 import itertools
 import json
 import os
-import pytz
 import shutil
 import sys
 import tempfile
 import unittest
 from io import StringIO
+from zoneinfo import ZoneInfo
 
 from .backends import TaskWarrior
 from .task import Task, ReadOnlyDictView
@@ -1110,8 +1110,7 @@ def test_export_data(self):
             self.tw,
             description='test task',
             project='Home',
-            due=pytz.utc.localize(
-                datetime.datetime(2015, 1, 1, 23, 23, 23)),
+            due=datetime.datetime(2015, 1, 1, 23, 23, 23, tzinfo=ZoneInfo('UTC')),
         )
 
         # Check that the output is a permutation of:
@@ -1135,8 +1134,8 @@ def setUp(self):
         self.zone = local_zone
         self.localdate_naive = datetime.datetime(2015, 2, 2)
         self.localtime_naive = datetime.datetime(2015, 2, 2, 0, 0, 0)
-        self.localtime_aware = self.zone.localize(self.localtime_naive)
-        self.utctime_aware = self.localtime_aware.astimezone(pytz.utc)
+        self.localtime_aware = self.localtime_naive.replace(tzinfo=self.zone)
+        self.utctime_aware = self.localtime_aware.astimezone(ZoneInfo('UTC'))
 
     def test_timezone_naive_datetime_setitem(self):
         t = Task(self.tw, description='test task')
@@ -1217,7 +1216,7 @@ def test_simple_now_conversion(self):
                 return
 
         t = Task(self.tw, description='test task', due='now')
-        now = local_zone.localize(datetime.datetime.now())
+        now = datetime.datetime.now().replace(tzinfo=local_zone)
 
         # Assert that both times are not more than 5 seconds apart
         if sys.version_info < (2, 7):
@@ -1237,24 +1236,26 @@ def test_simple_eoy_conversion(self):
                 return
 
         t = Task(self.tw, description='test task', due='eoy')
-        now = local_zone.localize(datetime.datetime.now())
-        eoy = local_zone.localize(datetime.datetime(
+        now = datetime.datetime.now().replace(tzinfo=local_zone)
+        eoy = datetime.datetime(
             year=now.year,
             month=12,
             day=31,
             hour=23,
             minute=59,
             second=59,
-        ))
+            tzinfo=local_zone
+        )
         if self.tw.version >= '2.5.2' and self.tw.version < '2.6.0':
-            eoy = local_zone.localize(datetime.datetime(
+            eoy = datetime.datetime(
                 year=now.year+1,
                 month=1,
                 day=1,
                 hour=0,
                 minute=0,
                 second=0,
-            ))
+                tzinfo=local_zone
+            )
         self.assertEqual(eoy, t['due'])
 
     def test_complex_eoy_conversion(self):
@@ -1267,27 +1268,25 @@ def test_complex_eoy_conversion(self):
                 return
 
         t = Task(self.tw, description='test task', due='eoy - 4 months')
-        now = local_zone.localize(datetime.datetime.now())
-        due_date = local_zone.localize(
-            datetime.datetime(
-                year=now.year,
-                month=12,
-                day=31,
-                hour=23,
-                minute=59,
-                second=59,
-            )
+        now = datetime.datetime.now().replace(tzinfo=local_zone)
+        due_date = datetime.datetime(
+            year=now.year,
+            month=12,
+            day=31,
+            hour=23,
+            minute=59,
+            second=59,
+            tzinfo=local_zone
         ) - datetime.timedelta(0, 4 * 30 * 86400)
         if self.tw.version >= '2.5.2' and self.tw.version < '2.6.0':
-            due_date = local_zone.localize(
-                datetime.datetime(
-                    year=now.year+1,
-                    month=1,
-                    day=1,
-                    hour=0,
-                    minute=0,
-                    second=0,
-                )
+            due_date = datetime.datetime(
+                year=now.year+1,
+                month=1,
+                day=1,
+                hour=0,
+                minute=0,
+                second=0,
+                tzinfo=local_zone
             ) - datetime.timedelta(0, 4 * 30 * 86400)
         self.assertEqual(due_date, t['due'])