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

@@ -17,6 +17,7 @@
 
 from calendar import timegm
 from datetime import datetime, timedelta, timezone
+from typing import Optional, Tuple
 
 from metomi.isodatetime.timezone import (
     get_local_time_zone_format, get_local_time_zone, TimeZoneFormatMode)
@@ -42,10 +43,7 @@
 TIME_ZONE_STRING_LOCAL_EXTENDED = get_local_time_zone_format(
     TimeZoneFormatMode.extended)
 TIME_ZONE_STRING_UTC = "Z"
-TIME_ZONE_UTC_UTC_OFFSET = (0, 0)
 TIME_ZONE_LOCAL_UTC_OFFSET = get_local_time_zone()
-TIME_ZONE_LOCAL_UTC_OFFSET_HOURS = TIME_ZONE_LOCAL_UTC_OFFSET[0]
-TIME_ZONE_LOCAL_UTC_OFFSET_MINUTES = TIME_ZONE_LOCAL_UTC_OFFSET[1]
 
 TIME_ZONE_LOCAL_INFO = {
     "hours": TIME_ZONE_LOCAL_UTC_OFFSET[0],
@@ -55,8 +53,8 @@
 }
 
 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
 }
@@ -74,8 +72,9 @@
     _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: Optional[bool] = 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
@@ -85,9 +84,9 @@
 
     """
     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,
@@ -113,9 +112,13 @@
                            use_basic_format=use_basic_format)
 
 
-def get_time_string(date_time, display_sub_seconds=False,
-                    override_use_utc=None, use_basic_format=False,
-                    date_time_is_local=False, custom_time_zone_info=None):
+def get_time_string(
+    date_time: datetime,
+    display_sub_seconds: bool = False,
+    override_use_utc: Optional[bool] = None,
+    use_basic_format: bool = False,
+    date_time_is_local: bool = False,
+):
     """Return a string representing the current system time.
 
     Arguments:
@@ -133,46 +136,20 @@
     most useful for filenames where ":" may cause problems.
     date_time_is_local - a boolean that, if True, indicates that
     the date_time argument object is in the local time zone, not UTC.
-    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.
 
     """
-    time_zone_string = None
-    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 = TIME_ZONE_LOCAL_UTC_OFFSET_HOURS
-            date_time_minutes = TIME_ZONE_LOCAL_UTC_OFFSET_MINUTES
-        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(
-                hours=TIME_ZONE_LOCAL_UTC_OFFSET_HOURS,
-                minutes=TIME_ZONE_LOCAL_UTC_OFFSET_MINUTES
-            )
+            h, m = TIME_ZONE_LOCAL_UTC_OFFSET
+            date_time = date_time - timedelta(hours=h, minutes=m)
     else:
         if use_basic_format:
             time_zone_string = TIME_ZONE_STRING_LOCAL_BASIC
         else:
             time_zone_string = TIME_ZONE_STRING_LOCAL_EXTENDED
         if not date_time_is_local:
-            diff_hours = TIME_ZONE_LOCAL_UTC_OFFSET_HOURS
-            diff_minutes = TIME_ZONE_LOCAL_UTC_OFFSET_MINUTES
+            diff_hours, diff_minutes = TIME_ZONE_LOCAL_UTC_OFFSET
             date_time = date_time + timedelta(
                 hours=diff_hours, minutes=diff_minutes)
     if use_basic_format:
@@ -187,9 +164,11 @@
     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:
@@ -202,20 +181,15 @@
     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/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

@@ -14,10 +14,19 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import pytest
+from datetime import (
+    datetime,
+    timedelta,
+    timezone,
+)
 
 from metomi.isodatetime.data import CALENDAR
-from cylc.flow.wallclock import get_unix_time_from_time_string
+import pytest
+
+from cylc.flow.wallclock import (
+    get_time_string,
+    get_unix_time_from_time_string,
+)
 
 
 @pytest.mark.parametrize(
@@ -60,3 +69,27 @@ def test_get_unix_time_from_time_string_360(time_str, time_sec):
 def test_get_unix_time_from_time_string_error(value, error):
     with pytest.raises(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, monkeypatch: pytest.MonkeyPatch):
+    """Basic check it handles naive and timezone-aware datetime objects.
+
+    Currently we just ignore the timezone information in the datetime object.
+    """
+    # Mock UTC time zone:
+    monkeypatch.setattr(
+        'cylc.flow.wallclock.TIME_ZONE_LOCAL_UTC_OFFSET', (0, 0)
+    )
+    for fmt in ('BASIC', 'EXTENDED'):
+        monkeypatch.setattr(
+            f'cylc.flow.wallclock.TIME_ZONE_STRING_LOCAL_{fmt}', 'Z'
+        )
+
+    assert get_time_string(
+        datetime(2077, 2, 8, 13, 42, 39, 123456, tz_info)
+    ) == '2077-02-08T13:42:39Z'

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 (
         (