DEPR: remove Categorical.to_list (#58000)

Author: jbrockmendel

doc/source/whatsnew/v3.0.0.rst

@@ -211,6 +211,7 @@ Removal of prior version deprecations/changes
 - Enforced deprecation of strings ``T``, ``L``, ``U``, and ``N`` denoting units in :class:`Timedelta` (:issue:`57627`)
 - Enforced deprecation of the behavior of :func:`concat` when ``len(keys) != len(objs)`` would truncate to the shorter of the two. Now this raises a ``ValueError`` (:issue:`43485`)
 - Enforced deprecation of values "pad", "ffill", "bfill", and "backfill" for :meth:`Series.interpolate` and :meth:`DataFrame.interpolate` (:issue:`57869`)
+- Enforced deprecation removing :meth:`Categorical.to_list`, use ``obj.tolist()`` instead (:issue:`51254`)
 - Enforced silent-downcasting deprecation for :ref:`all relevant methods <whatsnew_220.silent_downcasting>` (:issue:`54710`)
 - In :meth:`DataFrame.stack`, the default value of ``future_stack`` is now ``True``; specifying ``False`` will raise a ``FutureWarning`` (:issue:`55448`)
 - Iterating over a :class:`.DataFrameGroupBy` or :class:`.SeriesGroupBy` will return tuples of length 1 for the groups when grouping by ``level`` a list of length 1 (:issue:`50064`)

pandas/core/arrays/categorical.py

@@ -626,19 +626,6 @@ def astype(self, dtype: AstypeArg, copy: bool = True) -> ArrayLike:
 
         return result
 
-    def to_list(self) -> list:
-        """
-        Alias for tolist.
-        """
-        # GH#51254
-        warnings.warn(
-            "Categorical.to_list is deprecated and will be removed in a future "
-            "version. Use obj.tolist() instead",
-            FutureWarning,
-            stacklevel=find_stack_level(),
-        )
-        return self.tolist()
-
     @classmethod
     def _from_inferred_categories(
         cls, inferred_categories, inferred_codes, dtype, true_values=None

pandas/tests/arrays/categorical/test_api.py

@@ -18,13 +18,6 @@
 
 
 class TestCategoricalAPI:
-    def test_to_list_deprecated(self):
-        # GH#51254
-        cat1 = Categorical(list("acb"), ordered=False)
-        msg = "Categorical.to_list is deprecated and will be removed"
-        with tm.assert_produces_warning(FutureWarning, match=msg):
-            cat1.to_list()
-
     def test_ordered_api(self):
         # GH 9347
         cat1 = Categorical(list("acb"), ordered=False)