GH ref

doc/source/whatsnew/v2.2.0.rst

@@ -396,11 +396,11 @@ Other Deprecations
 - Deprecated the ``errors="ignore"`` option in :func:`to_datetime`, :func:`to_timedelta`, and :func:`to_numeric`; explicitly catch exceptions instead (:issue:`54467`)
 - Deprecated the ``fastpath`` keyword in the :class:`Series` constructor (:issue:`20110`)
 - Deprecated the ``ordinal`` keyword in :class:`PeriodIndex`, use :meth:`PeriodIndex.from_ordinals` instead (:issue:`55960`)
+- Deprecated the behavior of :meth:`Series.value_counts` and :meth:`Index.value_counts` with object dtype; in a future version these will not perform dtype inference on the resulting :class:`Index`, do ``result.index = result.index.infer_objects()`` to retain the old behavior (:issue:`56161`)
 - Deprecated the extension test classes ``BaseNoReduceTests``, ``BaseBooleanReduceTests``, and ``BaseNumericReduceTests``, use ``BaseReduceTests`` instead (:issue:`54663`)
 - Deprecated the option ``mode.data_manager`` and the ``ArrayManager``; only the ``BlockManager`` will be available in future versions (:issue:`55043`)
 - Deprecated the previous implementation of :class:`DataFrame.stack`; specify ``future_stack=True`` to adopt the future version (:issue:`53515`)
 - Deprecating downcasting the results of :meth:`DataFrame.fillna`, :meth:`Series.fillna`, :meth:`DataFrame.ffill`, :meth:`Series.ffill`, :meth:`DataFrame.bfill`, :meth:`Series.bfill` in object-dtype cases. To opt in to the future version, use ``pd.set_option("future.no_silent_downcasting", True)`` (:issue:`54261`)
-- Deprecated the behavior of :meth:`Series.value_counts` and :meth:`Index.value_counts` with object dtype; in a future version these will not perform dtype inference on the resulting :class:`Index`, do ``result.index = result.index.infer_objects()`` to retain the old behavior (:issue:`??`)
 -
 
 .. ---------------------------------------------------------------------------

pandas/core/algorithms.py

@@ -934,6 +934,7 @@ def value_counts_internal(
                 idx = idx.astype(object)
             elif idx.dtype != keys.dtype:
                 warnings.warn(
+                    # GH#56161
                     "The behavior of value_counts with object-dtype is deprecated. "
                     "In a future version, this will *not* perform dtype inference "
                     "on the resulting index. To retain the old behavior, use "

pandas/tests/base/test_value_counts.py

@@ -339,6 +339,7 @@ def test_value_counts_with_nan(dropna, index_or_series):
 
 
 def test_value_counts_object_inference_deprecated():
+    # GH#56161
     dti = pd.date_range("2016-01-01", periods=3, tz="UTC")
 
     idx = dti.astype(object)