ENH: deprecate numeric_only=None in reductions during 2.x\n\nCall deprecate_numeric_only_none and validate_bool_kwarg at central reduction entry points (DataFrame._reduce, Series._reduce, GroupBy._cython_agg_general, Rolling._validate_numeric_only). Emit PandasFutureWarning for numeric_only=None (GH#53098).

Author: divya1974

pandas/core/frame.py

@@ -11926,6 +11926,18 @@ def _reduce(
         if axis is not None:
             axis = self._get_axis_number(axis)
 
+        # validate numeric_only is strictly a bool (disallow None, ints, etc.)
+        # Deprecate passing None to numeric_only: warn now, error in a future
+        # release. See GH#53098.
+        from pandas.util._validators import deprecate_numeric_only_none
+
+        deprecate_numeric_only_none(numeric_only, "numeric_only")
+        # During the 2.x cycle we warn if numeric_only is None but continue to
+        # accept None; later releases should set none_allowed=False to raise.
+        validate_bool_kwarg(
+            numeric_only, "numeric_only", none_allowed=True, int_allowed=False
+        )
+
         def func(values: np.ndarray):
             # We only use this in the case that operates on self.values
             return op(values, axis=axis, skipna=skipna, **kwds)

pandas/core/groupby/groupby.py

@@ -70,6 +70,7 @@ class providing the base-class of operations.
     doc,
 )
 from pandas.util._exceptions import find_stack_level
+from pandas.util._validators import validate_bool_kwarg
 
 from pandas.core.dtypes.cast import (
     coerce_indexer_dtype,
@@ -1756,6 +1757,16 @@ def _cython_agg_general(
         # Note: we never get here with how="ohlc" for DataFrameGroupBy;
         #  that goes through SeriesGroupBy
 
+        # validate numeric_only is strictly a bool (disallow None, ints, etc.)
+        # Deprecate passing None to numeric_only: warn now, error in a future
+        # release. See GH#53098.
+        from pandas.util._validators import deprecate_numeric_only_none
+
+        deprecate_numeric_only_none(numeric_only, "numeric_only")
+        validate_bool_kwarg(
+            numeric_only, "numeric_only", none_allowed=True, int_allowed=False
+        )
+
         data = self._get_data_to_aggregate(numeric_only=numeric_only, name=how)
 
         def array_func(values: ArrayLike) -> ArrayLike:

pandas/core/series.py

@@ -6664,6 +6664,16 @@ def _reduce(
         if axis is not None:
             self._get_axis_number(axis)
 
+        # validate numeric_only is strictly a bool (disallow None, ints, etc.)
+        # Deprecate passing None to numeric_only: warn now, error in a future
+        # release. See GH#53098.
+        from pandas.util._validators import deprecate_numeric_only_none
+
+        deprecate_numeric_only_none(numeric_only, "numeric_only")
+        validate_bool_kwarg(
+            numeric_only, "numeric_only", none_allowed=True, int_allowed=False
+        )
+
         if isinstance(delegate, ExtensionArray):
             # dispatch to ExtensionArray interface
             return delegate._reduce(name, skipna=skipna, **kwds)

pandas/core/window/rolling.py

@@ -35,6 +35,7 @@
     Substitution,
     doc,
 )
+from pandas.util._validators import validate_bool_kwarg
 
 from pandas.core.dtypes.common import (
     ensure_float64,
@@ -254,6 +255,16 @@ def _validate_numeric_only(self, name: str, numeric_only: bool) -> None:
         numeric_only : bool
             Value passed by user.
         """
+        # validate numeric_only argument type
+        # Deprecate passing None to numeric_only: warn now, error in a future
+        # release. See GH#53098.
+        from pandas.util._validators import deprecate_numeric_only_none
+
+        deprecate_numeric_only_none(numeric_only, "numeric_only")
+        validate_bool_kwarg(
+            numeric_only, "numeric_only", none_allowed=True, int_allowed=False
+        )
+
         if (
             self._selected_obj.ndim == 1
             and numeric_only