Make python timezone conversions handle more cases

py/server/deephaven/time.py

@@ -1,12 +1,14 @@
 #
-# Copyright (c) 2016-2023 Deephaven Data Labs and Patent Pending
+# Copyright (c) 2016-2024 Deephaven Data Labs and Patent Pending
 #
 
 """ This module defines functions for handling Deephaven date/time data. """
 
 from __future__ import annotations
 
 import datetime
+import zoneinfo
+import pytz
 from typing import Union, Optional, Literal
 
 import jpy
@@ -165,6 +167,60 @@ def time_zone_alias_rm(alias: str) -> bool:
 
 # region Conversions: Python To Java
 
+def _tzinfo_to_j_time_zone(tzi: datetime.tzinfo) -> TimeZone:
+ """
+ Converts a Python time zone to a Java TimeZone.
+
+ Args:
+ tzi: time zone info
+
+ Returns:
+ Java TimeZone
+ """
+
+ if not tzi:
+ return None
+
+ # Handle pytz time zones
+
+ if isinstance(tzi, pytz.tzinfo.BaseTzInfo):
+ return _JDateTimeUtils.parseTimeZone(tzi.zone)
+
+ # Handle zoneinfo time zones
+
+ if isinstance(tzi, zoneinfo.ZoneInfo):
+ return _JDateTimeUtils.parseTimeZone(tzi.key)
+
+ # Handle constant UTC offset time zones (datetime.timezone)
+
+ if isinstance(tzi, datetime.timezone):
+ offset = tzi.utcoffset(None)
+
+ if offset is None:
+ raise ValueError("Unable to determine the time zone UTC offset")
+
+ if not offset:
+ return _JDateTimeUtils.parseTimeZone("UTC")
+
+ if offset.microseconds != 0 or offset.seconds%60 != 0:
+ raise ValueError(f"Unsupported time zone offset contains fractions of a minute: {offset}")
+
+ ts = offset.total_seconds()
+
+ if ts >= 0:
+ sign = "+"
+ else:
+ sign = "-"
+ ts = -ts
+
+ hours = int(ts / 3600)
+ minutes = int((ts % 3600) / 60)
+ return _JDateTimeUtils.parseTimeZone(f"UTC{sign}{hours:02d}:{minutes:02d}")
+
+ details = "\n\t".join([f"type={type(tzi).mro()}"] +
+ [f"obj.{attr}={getattr(tzi, attr)}" for attr in dir(tzi) if not attr.startswith("_")])
+ raise TypeError(f"Unsupported conversion: {str(type(tzi))} -> TimeZone\n\tDetails:\n\t{details}")
+
 
 def to_j_time_zone(tz: Union[None, TimeZone, str, datetime.tzinfo, datetime.datetime, pandas.Timestamp]) -> \
  Optional[TimeZone]:
@@ -192,12 +248,15 @@ def to_j_time_zone(tz: Union[None, TimeZone, str, datetime.tzinfo, datetime.date
  elif isinstance(tz, str):
  return _JDateTimeUtils.parseTimeZone(tz)
  elif isinstance(tz, datetime.tzinfo):
- return _JDateTimeUtils.parseTimeZone(str(tz))
+ return _tzinfo_to_j_time_zone(tz)
  elif isinstance(tz, datetime.datetime):
- if not tz.tzname():
- return _JDateTimeUtils.parseTimeZone(tz.astimezone().tzname())
+ tzi = tz.tzinfo
+ rst = _tzinfo_to_j_time_zone(tzi)
+
+ if not rst:
+ raise ValueError("datetime is not time zone aware")
 
- return _JDateTimeUtils.parseTimeZone(tz.tzname())
+ return rst
  else:
  raise TypeError("Unsupported conversion: " + str(type(tz)) + " -> TimeZone")
  except TypeError as e:

py/server/tests/test_time.py

@@ -1,10 +1,11 @@
 #
-# Copyright (c) 2016-2022 Deephaven Data Labs and Patent Pending
+# Copyright (c) 2016-2024 Deephaven Data Labs and Patent Pending
 #
 
 import unittest
 from time import sleep
 import datetime
+import zoneinfo
 import pandas as pd
 import numpy as np
 
@@ -72,8 +73,9 @@ def test_to_j_time_zone(self):
  self.assertEqual(str(tz), "UTC")
 
  pytz = datetime.datetime.now()
- tz = to_j_time_zone(pytz)
- self.assertEqual(str(tz), "UTC")
+ with self.assertRaises(DHError):
+ tz = to_j_time_zone(pytz)
+ self.fail("Expected DHError")
 
  pytz = datetime.datetime.now().astimezone()
  tz = to_j_time_zone(pytz)
@@ -93,6 +95,35 @@ def test_to_j_time_zone(self):
  tz2 = to_j_time_zone(tz1)
  self.assertEqual(tz1, tz2)
 
+ ts = pd.Timestamp("2022-07-07", tz="America/New_York")
+ self.assertEqual(to_j_time_zone(ts), to_j_time_zone("America/New_York"))
+
+ dttz = datetime.timezone(offset=datetime.timedelta(hours=5), name="XYZ")
+ dt = datetime.datetime(2022, 7, 7, 14, 21, 17, 123456, tzinfo=dttz)
+ self.assertEqual(to_j_time_zone(dttz), to_j_time_zone("UTC+5"))
+ self.assertEqual(to_j_time_zone(dt), to_j_time_zone("UTC+5"))
+
+ dttz = datetime.timezone(offset=-datetime.timedelta(hours=5), name="XYZ")
+ dt = datetime.datetime(2022, 7, 7, 14, 21, 17, 123456, tzinfo=dttz)
+ self.assertEqual(to_j_time_zone(dttz), to_j_time_zone("UTC-5"))
+ self.assertEqual(to_j_time_zone(dt), to_j_time_zone("UTC-5"))
+
+ dttz = datetime.timezone(offset=-datetime.timedelta(hours=5, microseconds=10), name="XYZ")
+ dt = datetime.datetime(2022, 7, 7, 14, 21, 17, 123456, tzinfo=dttz)
+
+ with self.assertRaises(DHError):
+ to_j_time_zone(dttz)
+ self.fail("Expected DHError")
+
+ with self.assertRaises(DHError):
+ to_j_time_zone(dt)
+ self.fail("Expected DHError")
+
+ dttz = zoneinfo.ZoneInfo("America/New_York")
+ dt = datetime.datetime(2022, 7, 7, 14, 21, 17, 123456, tzinfo=dttz)
+ self.assertEqual(to_j_time_zone(dttz), to_j_time_zone("America/New_York"))
+ self.assertEqual(to_j_time_zone(dt), to_j_time_zone("America/New_York"))
+
  with self.assertRaises(TypeError):
  to_j_time_zone(False)
  self.fail("Expected TypeError")