Unify _to_date converter across arrow and polars modules

Moved the flexible _to_date function (handling str, datetime, and date)
to the base converter module and updated arrow/polars converters to
import and reuse it, eliminating duplicate implementations.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: laughingman7743

pyathena/arrow/converter.py

@@ -2,14 +2,13 @@
 from __future__ import annotations
 
 import logging
-from builtins import isinstance
 from copy import deepcopy
-from datetime import date, datetime
-from typing import Any, Callable, Dict, Optional, Type, Union
+from typing import Any, Callable, Dict, Optional, Type
 
 from pyathena.converter import (
     Converter,
     _to_binary,
+    _to_date,
     _to_decimal,
     _to_default,
     _to_json,
@@ -19,14 +18,6 @@
 _logger = logging.getLogger(__name__)  # type: ignore
 
 
-def _to_date(value: Optional[Union[str, datetime]]) -> Optional[date]:
-    if value is None:
-        return None
-    if isinstance(value, datetime):
-        return value.date()
-    return datetime.strptime(value, "%Y-%m-%d").date()
-
-
 _DEFAULT_ARROW_CONVERTERS: Dict[str, Callable[[Optional[str]], Optional[Any]]] = {
     "date": _to_date,
     "time": _to_time,

pyathena/converter.py

@@ -8,7 +8,7 @@
 from copy import deepcopy
 from datetime import date, datetime, time
 from decimal import Decimal
-from typing import Any, Callable, Dict, List, Optional, Type
+from typing import Any, Callable, Dict, List, Optional, Type, Union
 
 from dateutil.tz import gettz
 
@@ -17,10 +17,14 @@
 _logger = logging.getLogger(__name__)  # type: ignore
 
 
-def _to_date(varchar_value: Optional[str]) -> Optional[date]:
-    if varchar_value is None:
+def _to_date(value: Optional[Union[str, datetime, date]]) -> Optional[date]:
+    if value is None:
         return None
-    return datetime.strptime(varchar_value, "%Y-%m-%d").date()
+    if isinstance(value, datetime):
+        return value.date()
+    if isinstance(value, date):
+        return value
+    return datetime.strptime(value, "%Y-%m-%d").date()
 
 
 def _to_datetime(varchar_value: Optional[str]) -> Optional[datetime]:

pyathena/polars/converter.py

@@ -3,12 +3,12 @@
 
 import logging
 from copy import deepcopy
-from datetime import date, datetime
-from typing import Any, Callable, Dict, Optional, Union
+from typing import Any, Callable, Dict, Optional
 
 from pyathena.converter import (
     Converter,
     _to_binary,
+    _to_date,
     _to_default,
     _to_json,
     _to_time,
@@ -17,16 +17,6 @@
 _logger = logging.getLogger(__name__)
 
 
-def _to_date(value: Optional[Union[str, datetime, date]]) -> Optional[date]:
-    if value is None:
-        return None
-    if isinstance(value, datetime):
-        return value.date()
-    if isinstance(value, date):
-        return value
-    return datetime.strptime(value, "%Y-%m-%d").date()
-
-
 _DEFAULT_POLARS_CONVERTERS: Dict[str, Callable[[Optional[str]], Optional[Any]]] = {
     "date": _to_date,
     "time": _to_time,