Address some warnings

cylc/flow/rundb.py

@@ -452,7 +452,9 @@ def close(self) -> None:
     def connect(self) -> sqlite3.Connection:
         """Connect to the database."""
         if self.conn is None:
-            self.conn = sqlite3.connect(self.db_file_name, self.CONN_TIMEOUT)
+            self.conn = sqlite3.connect(
+                self.db_file_name, timeout=self.CONN_TIMEOUT
+            )
         return self.conn
 
     def create_tables(self):

cylc/flow/wallclock.py

@@ -16,11 +16,17 @@
 """Wall clock related utilities."""
 
 from calendar import timegm
-from datetime import datetime, timedelta, timezone
-from typing import Dict, Optional
+from datetime import (
+    datetime,
+    timedelta,
+    timezone,
+)
 
 from metomi.isodatetime.timezone import (
-    get_local_time_zone_format, get_local_time_zone, TimeZoneFormatMode)
+    TimeZoneFormatMode,
+    get_local_time_zone,
+    get_local_time_zone_format,
+)
 
 
 DATE_TIME_FORMAT_BASIC = "%Y%m%dT%H%M%S"
@@ -39,7 +45,6 @@
 TIME_FORMAT_EXTENDED_SUB_SECOND = "%H:%M:%S.%f"
 
 TIME_ZONE_STRING_UTC = "Z"
-TIME_ZONE_UTC_UTC_OFFSET = (0, 0)
 
 TIME_ZONE_LOCAL_INFO = {
     "hours": get_local_time_zone()[0],
@@ -51,8 +56,8 @@
 }
 
 TIME_ZONE_UTC_INFO = {
-    "hours": TIME_ZONE_UTC_UTC_OFFSET[0],
-    "minutes": TIME_ZONE_UTC_UTC_OFFSET[1],
+    "hours": 0,
+    "minutes": 0,
     "string_basic": TIME_ZONE_STRING_UTC,
     "string_extended": TIME_ZONE_STRING_UTC
 }
@@ -70,8 +75,9 @@ def set_utc_mode(mode):
     _FLAGS['utc_mode'] = bool(mode)
 
 
-def now(override_use_utc=None):
-    """Return a current-time datetime.datetime and a UTC timezone flag.
+def now(override_use_utc: bool | None = None) -> tuple[datetime, bool]:
+    """Return a current-time, timezone-aware datetime.datetime and a flag
+    indicating whether it is UTC or not.
 
     Keyword arguments:
     override_use_utc (default None) - a boolean (or None) that, if
@@ -81,9 +87,9 @@ def now(override_use_utc=None):
 
     """
     if override_use_utc or (override_use_utc is None and _FLAGS['utc_mode']):
-        return datetime.utcnow(), False
+        return datetime.now(timezone.utc), False
     else:
-        return datetime.now(), True
+        return datetime.now().astimezone(), True
 
 
 def get_current_time_string(display_sub_seconds=False, override_use_utc=None,
@@ -112,10 +118,9 @@ def get_current_time_string(display_sub_seconds=False, override_use_utc=None,
 def get_time_string(
     date_time: datetime,
     display_sub_seconds: bool = False,
-    override_use_utc: Optional[bool] = None,
+    override_use_utc: bool | None = None,
     use_basic_format: bool = False,
     date_time_is_local: bool = False,
-    custom_time_zone_info: Optional[Dict] = None,
 ):
     """Return a string representing the current system time.
 
@@ -135,40 +140,10 @@ def get_time_string(
         date_time_is_local:
             Indicates that the date_time argument
             object is in the local time zone, not UTC.
-        custom_time_zone_info:
-            A dictionary that enforces a particular time zone:
-
-            .. code-block:: python
-                {
-                    "hours": _hours,           # offset from UTC
-                    "minutes": _minutes,       # offset from utc
-                    "string_basic": _string,    # timezone designators
-                    "string_extened": _string
-                }
-
-            Usage of ``string_basic`` or ``string_extended`` is
-            switched by ``use_basic_format``.
 
     """
-    time_zone_string = None
     local_tz = get_local_time_zone()
-    if custom_time_zone_info is not None:
-        custom_hours = custom_time_zone_info["hours"]
-        custom_minutes = custom_time_zone_info["minutes"]
-        if use_basic_format:
-            custom_string = custom_time_zone_info["string_basic"]
-        else:
-            custom_string = custom_time_zone_info["string_extended"]
-        if date_time_is_local:
-            date_time_hours, date_time_minutes = local_tz
-        else:
-            date_time_hours, date_time_minutes = (0, 0)
-        diff_hours = custom_hours - date_time_hours
-        diff_minutes = custom_minutes - date_time_minutes
-        date_time = date_time + timedelta(
-            hours=diff_hours, minutes=diff_minutes)
-        time_zone_string = custom_string
-    elif override_use_utc or (override_use_utc is None and _FLAGS['utc_mode']):
+    if override_use_utc or (override_use_utc is None and _FLAGS['utc_mode']):
         time_zone_string = TIME_ZONE_STRING_UTC
         if date_time_is_local:
             date_time = date_time - timedelta(
@@ -198,9 +173,11 @@ def get_time_string(
     return date_time_string + time_zone_string
 
 
-def get_time_string_from_unix_time(unix_time, display_sub_seconds=False,
-                                   use_basic_format=False,
-                                   custom_time_zone_info=None):
+def get_time_string_from_unix_time(
+    unix_time: float,
+    display_sub_seconds: bool = False,
+    use_basic_format: bool = False,
+) -> str:
     """Convert a unix timestamp into a local time zone datetime.datetime.
 
     Arguments:
@@ -213,20 +190,15 @@ def get_time_string_from_unix_time(unix_time, display_sub_seconds=False,
     use_basic_format (default False) - a boolean that, if True,
     represents the date/time without "-" or ":" delimiters. This is
     most useful for filenames where ":" may cause problems.
-    custom_time_zone_info (default None) - a dictionary that enforces
-    a particular time zone. It looks like {"hours": _hours,
-    "minutes": _minutes, "string": _string} where _hours and _minutes
-    are the hours and minutes offset from UTC and _string is the string
-    to use as the time zone designator.
 
     """
-    date_time = datetime.fromtimestamp(unix_time, timezone.utc)
-    return get_time_string(date_time,
-                           display_sub_seconds=display_sub_seconds,
-                           use_basic_format=use_basic_format,
-                           override_use_utc=None,
-                           date_time_is_local=False,
-                           custom_time_zone_info=custom_time_zone_info)
+    return get_time_string(
+        datetime.fromtimestamp(unix_time, timezone.utc),
+        display_sub_seconds=display_sub_seconds,
+        use_basic_format=use_basic_format,
+        override_use_utc=None,
+        date_time_is_local=False,
+    )
 
 
 def get_unix_time_from_time_string(datetime_string):

tests/conftest.py

@@ -278,7 +278,7 @@ def set_timezone(monkeypatch):
 
     Will use a very implausible timezone if none is provided.
     """
-    def patch(time_zone: str = 'XXX-19:17'):
+    def patch(time_zone: str):
         monkeypatch.setenv('TZ', time_zone)
         time.tzset()
 

tests/unit/cycling/test_iso8601.py

@@ -14,7 +14,10 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from datetime import datetime
+from datetime import (
+    datetime,
+    timezone,
+)
 
 import pytest
 from pytest import param
@@ -892,10 +895,10 @@ def test_next_simple_no_now(set_cycling_type):
     point = "next(T00Z)+P1D"
     output = ingest_time(point, my_now)
 
-    current_time = datetime.utcnow()
+    current_time = datetime.now(timezone.utc)
     # my_now is None, but ingest_time will have used a similar time, and
     # the returned value must be after current_time
-    output_time = datetime.strptime(output, "%Y%m%dT%H%MZ")
+    output_time = datetime.strptime(output, "%Y%m%dT%H%M%z")
     assert current_time < output_time
 
 

tests/unit/test_wallclock.py

@@ -14,11 +14,16 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from datetime import datetime
+from datetime import (
+    datetime,
+    timedelta,
+    timezone,
+)
+
+from metomi.isodatetime.data import CALENDAR
 import pytest
 from pytest import param
 
-from metomi.isodatetime.data import CALENDAR
 from cylc.flow.wallclock import (
     get_current_time_string,
     get_time_string,
@@ -68,12 +73,28 @@ def test_get_unix_time_from_time_string_error(value, error):
         get_unix_time_from_time_string(value)
 
 
+@pytest.mark.parametrize('tz_info', [
+    pytest.param(None, id="naive"),
+    pytest.param(timezone.utc, id="utc-tz-aware"),
+    pytest.param(timezone(timedelta(hours=5)), id="custom-tz-aware"),
+])
+def test_get_time_string_tzinfo(tz_info, set_timezone):
+    """Basic check it handles naive and timezone-aware datetime objects.
+
+    Currently we just ignore the timezone information in the datetime object.
+    """
+    set_timezone('UTC')
+    assert get_time_string(
+        datetime(2077, 2, 8, 13, 42, 39, 123456, tz_info)
+    ) == '2077-02-08T13:42:39Z'
+
+
 def test_get_current_time_string(set_timezone):
     """It reacts to local time zone changes.
 
     https://github.com/cylc/cylc-flow/issues/6701
     """
-    set_timezone()
+    set_timezone('XXX-19:17')
     res = get_current_time_string()
     assert res[-6:] == '+19:17'
 
@@ -95,46 +116,12 @@ def test_get_current_time_string(set_timezone):
         ),
         param(
             datetime(2000, 12, 13, 15, 30, 12, 123456),
-            {
-                'custom_time_zone_info': {
-                    'hours': 0,
-                    'minutes': -20,
-                    'string_basic': 'XXX+00:20',
-                },
-                'use_basic_format': True
-            },
-            '20001213T151012XXX+00:20',
-            id='custom_time_zone_info_string_basic',
-        ),
-        param(
-            datetime(2000, 12, 13, 15, 30, 12, 123456),
-            {
-                'custom_time_zone_info': {
-                    'hours': 0,
-                    'minutes': -20,
-                    'string_extended': ':UK/Exeter',
-                },
-                'use_basic_format': False
-            },
-            '2000-12-13T15:10:12:UK/Exeter',
-            id='custom_time_zone_info_string_extended',
-        ),
-        param(
-            datetime(2000, 12, 13, 15, 30, 12, 123456),
-            {
-                'custom_time_zone_info': {
-                    'hours': 0,
-                    'minutes': -20,
-                    'string_extended': ':UK/Exeter',
-                },
-                'use_basic_format': False,
-                'date_time_is_local': True,
-            },
-            '2000-12-12T19:53:12:UK/Exeter',
-            id='date_time_is_local',
+            {'use_basic_format': True},
+            '20001214T104712+1917',
+            id='basic_format',
         ),
     ),
 )
 def test_get_time_string(set_timezone, arg, kwargs, expect):
-    set_timezone()
+    set_timezone('XXX-19:17')
     assert get_time_string(arg, **kwargs) == expect

tests/unit/tui/test_util.py

@@ -17,7 +17,8 @@
 
 from datetime import (
     datetime,
-    timedelta
+    timedelta,
+    timezone
 )
 from unittest.mock import Mock
 
@@ -171,7 +172,7 @@ def test_get_task_icon(
     start_time = None
     if start_offset is not None:
         start_time = get_time_string(
-            datetime.utcnow() - timedelta(seconds=start_offset)
+            datetime.now(timezone.utc) - timedelta(seconds=start_offset)
         )
     assert (
         (