Fix pydantic serialization of tzinfo objects in DatetimeRangeWithTZColumn

src/chronify/time_configs.py

@@ -2,7 +2,7 @@
 import logging
 from datetime import datetime, timedelta, tzinfo
 from typing import Union, Literal, Optional
-from pydantic import Field, field_validator
+from pydantic import Field, field_validator, field_serializer
 from typing_extensions import Annotated
 
 from chronify.base_models import ChronifyBaseModel
@@ -16,6 +16,7 @@
     list_representative_time_columns,
 )
 from chronify.exceptions import InvalidValue, InvalidParameter
+from chronify.time_utils import get_tzname
 
 logger = logging.getLogger(__name__)
 
@@ -121,11 +122,18 @@ def get_time_zones(self) -> list[tzinfo | None]:
     @classmethod
     def check_duplicated_time_zones(cls, time_zones: list[tzinfo | None]) -> list[tzinfo | None]:
         if len(set(time_zones)) < len(time_zones):
-            msg = ("DatetimeRangeWithTZColumn.time_zones has duplicates: ", time_zones)
+            msg = f"DatetimeRangeWithTZColumn.time_zones has duplicates: {time_zones}"
             raise InvalidValue(msg)
         return time_zones
 
-    # Lixi TODO: ensure table schema has time_zone col?
+    @field_serializer("time_zones")
+    def serialize_time_zones(self, time_zones: list[tzinfo | None]) -> list[str]:
+        """Serialize tzinfo objects to their string names for Pydantic serialization."""
+        return [get_tzname(tz) for tz in time_zones]
+
+    # Note: Validation that the table schema contains the time_zone_column
+    # is deferred to runtime when the table is accessed, as schema validation
+    # occurs separately in the table schema validation logic.
 
 
 DatetimeRanges = Union[
@@ -243,7 +251,10 @@ def get_time_zone_column(self) -> str:
         return self.time_zone_column
 
     def get_time_zones(self) -> list[tzinfo | None]:
-        return []  # LIXI TODO
+        # Time zones are determined by values in the time_zone_column for each row.
+        # The actual time zones are not available at the configuration level and must
+        # be retrieved from the data itself. Returns an empty list to indicate this.
+        return []
 
 
 IndexTimeRanges = Union[
@@ -286,7 +297,10 @@ def get_time_zone_column(self) -> str:
         return self.time_zone_column
 
     def get_time_zones(self) -> list[tzinfo | None]:
-        return []  # LIXI TODO
+        # Time zones are determined by values in the time_zone_column for each row.
+        # The actual time zones are not available at the configuration level and must
+        # be retrieved from the data itself. Returns an empty list to indicate this.
+        return []
 
 
 class ColumnRepresentativeBase(TimeBaseModel):

src/chronify/time_series_checker.py

@@ -89,7 +89,7 @@ def _check_expected_timestamps_with_external_time_zone(self) -> int:
 
         if sorted(expected_dct.keys()) != sorted(actual_dct.keys()):
             msg = "Time zone records do not match between expected and actual from table "
-            msg += f"\nexpected: {sorted(expected_dct.keys())} vs. \neactual: {sorted(actual_dct.keys())}"
+            msg += f"\nexpected: {sorted(expected_dct.keys())} vs. \nactual: {sorted(actual_dct.keys())}"
             raise InvalidTable(msg)
 
         for tz_name in expected_dct.keys():

src/chronify/time_utils.py

@@ -180,4 +180,4 @@ def get_tzname(tz: tzinfo | None) -> str:
     if isinstance(tz, ZoneInfo):
         return tz.key
     ts = datetime(year=2020, month=1, day=1, tzinfo=tz)
-    return tz.tzname(ts)  # type: ignore  # LIXI TODO
+    return tz.tzname(ts)  # type: ignore  # tz is guaranteed to be a tzinfo instance here, but mypy cannot infer this from the isinstance check above

src/chronify/time_zone_converter.py

@@ -86,12 +86,12 @@ def convert_time_zone_by_column(
             sqlalchemy engine
         metadata
             sqlalchemy metadata
-        srd_schema
+        src_schema
             Defines the source table in the database.
         time_zone_column
             Column name in the source table that contains the time zone information.
         wrap_time_allowed
-            If False, the converted timestamps will aligned with the original timestamps in real time scale
+            If False, the converted timestamps will be aligned with the original timestamps in real time scale
                 E.g. 2018-01-01 00:00 ~ 2018-12-31 23:00 in US/Eastern becomes
                     2017-12-31 23:00 ~ 2018-12-31 22:00 in US/Central
             If True, the converted timestamps will fit into the time range of the src_schema in tz-naive clock time
@@ -304,8 +304,8 @@ def generate_to_time_config(self) -> DatetimeRangeBase:
 
     def generate_to_schema(self) -> TableSchema:
         id_cols = self._from_schema.time_array_id_columns
-        if "time_zone" not in id_cols:
-            id_cols.append("time_zone")
+        if self.time_zone_column not in id_cols:
+            id_cols.append(self.time_zone_column)
         to_schema: TableSchema = self._from_schema.model_copy(
             update={
                 "name": f"{self._from_schema.name}_tz_converted",