Migrate from pytz to zoneinfo

https://listman.redhat.com/archives/anaconda-devel-list/2021-February/msg00020.html

anaconda.spec.in

@@ -122,7 +122,6 @@ Requires: subscription-manager >= %{subscriptionmanagerver}
 # which is apparently great for containers but unhelpful for the rest of us
 Requires: cracklib-dicts
 
-Requires: python3-pytz
 Requires: teamd
 %ifarch s390 s390x
 Requires: openssh

pyanaconda/isys/__init__.py

@@ -28,7 +28,7 @@
 import blivet.arch
 import time
 import datetime
-import pytz
+import zoneinfo
 
 from pyanaconda.anaconda_loggers import get_module_logger
 log = get_module_logger(__name__)
@@ -88,7 +88,7 @@ def set_system_date_time(year=None, month=None, day=None, hour=None, minute=None
 
     """
 
-    utc = pytz.UTC
+    utc = zoneinfo.ZoneInfo(key='UTC')
     # If no timezone is set, use UTC
     if not tz:
         tz = utc
@@ -104,13 +104,12 @@ def set_system_date_time(year=None, month=None, day=None, hour=None, minute=None
     minute = minute if minute is not None else now.minute
     second = second if second is not None else now.second
 
-    set_date = tz.localize(datetime.datetime(year, month, day, hour, minute, second))
+    set_date = datetime.datetime(year, month, day, hour, minute, second, tzinfo=tz)
 
     # Calculate the number of seconds between this time and timestamp 0
-    # see pytz docs, search for "Converting between timezones"
     # pylint bug here: https://github.com/PyCQA/pylint/issues/1104
     # pylint: disable=no-value-for-parameter
-    epoch = utc.localize(datetime.datetime.utcfromtimestamp(0)).astimezone(tz)
+    epoch = datetime.datetime.fromtimestamp(0, tz=utc).astimezone(tz)
     timestamp = (set_date - epoch).total_seconds()
 
     set_system_time(int(timestamp))

pyanaconda/timezone.py

@@ -22,9 +22,10 @@
 
 """
 
-import pytz
 import langtable
+import zoneinfo
 from collections import OrderedDict
+from functools import cache
 
 from pyanaconda.core import util
 from pyanaconda.core.constants import THREAD_STORAGE
@@ -38,8 +39,7 @@
 from pyanaconda.anaconda_loggers import get_module_logger
 log = get_module_logger(__name__)
 
-# The following zones are not in pytz.common_timezones and
-# Etc category in pytz.all_timezones includes some more,
+# The Etc category in available_timezones() includes some more,
 # however confusing ones (like UCT, GMT+0, GMT-0,...)
 ETC_ZONES = ['GMT+1', 'GMT+2', 'GMT+3', 'GMT+4', 'GMT+5', 'GMT+6', 'GMT+7',
              'GMT+8', 'GMT+9', 'GMT+10', 'GMT+11', 'GMT+12',
@@ -126,6 +126,17 @@ def get_preferred_timezone(territory):
     return timezones[0]
 
 
+@cache
+def available_timezones():
+    """
+    Get all timezones, but cached.
+
+    :rtype: set
+
+    """
+    return zoneinfo.available_timezones()
+
+
 def get_all_regions_and_timezones():
     """
     Get a dictionary mapping the regions to the list of their timezones.
@@ -136,7 +147,7 @@ def get_all_regions_and_timezones():
 
     result = OrderedDict()
 
-    for tz in pytz.common_timezones:
+    for tz in sorted(available_timezones()):
         parts = tz.split("/", 1)
 
         if len(parts) > 1:
@@ -157,9 +168,9 @@ def is_valid_timezone(timezone):
 
     """
 
-    etc_zones = ["Etc/" + zone for zone in ETC_ZONES]
+    etc_zones = {"Etc/" + zone for zone in ETC_ZONES}
 
-    return timezone in pytz.common_timezones + etc_zones
+    return timezone in available_timezones() + etc_zones
 
 
 def get_timezone(timezone):
@@ -170,4 +181,4 @@ def get_timezone(timezone):
     :rtype: datetime.tzinfo
     """
 
-    return pytz.timezone(timezone)
+    return zoneinfo.ZoneInfo(timezone)