DEPR: CategoricalIndex.take_nd (#30702)

Author: jbrockmendel

doc/source/whatsnew/v1.0.0.rst

@@ -568,7 +568,7 @@ Deprecations
 - :func:`eval` keyword argument "truediv" is deprecated and will be removed in a future version (:issue:`29812`)
 - :meth:`DateOffset.isAnchored` and :meth:`DatetOffset.onOffset` are deprecated and will be removed in a future version, use :meth:`DateOffset.is_anchored` and :meth:`DateOffset.is_on_offset` instead (:issue:`30340`)
 - ``pandas.tseries.frequencies.get_offset`` is deprecated and will be removed in a future version, use ``pandas.tseries.frequencies.to_offset`` instead (:issue:`4205`)
-- :meth:`Categorical.take_nd` is deprecated, use :meth:`Categorical.take` instead (:issue:`27745`)
+- :meth:`Categorical.take_nd` and :meth:`CategoricalIndex.take_nd` are deprecated, use :meth:`Categorical.take` and :meth:`CategoricalIndex.take` instead (:issue:`27745`)
 - The parameter ``numeric_only`` of :meth:`Categorical.min` and :meth:`Categorical.max` is deprecated and replaced with ``skipna`` (:issue:`25303`)
 - The parameter ``label`` in :func:`lreshape` has been deprecated and will be removed in a future version (:issue:`29742`)
 - ``pandas.core.index`` has been deprecated and will be removed in a future version, the public classes are available in the top-level namespace (:issue:`19711`)

pandas/core/indexes/category.py

@@ -1,5 +1,6 @@
 import operator
 from typing import Any, List
+import warnings
 
 import numpy as np
 
@@ -735,7 +736,13 @@ def take(self, indices, axis=0, allow_fill=True, fill_value=None, **kwargs):
         )
         return self._shallow_copy(taken)
 
-    take_nd = take
+    def take_nd(self, *args, **kwargs):
+        warnings.warn(
+            "CategoricalIndex.take_nd is deprecated, use CategoricalIndex.take instead",
+            FutureWarning,
+            stacklevel=2,
+        )
+        return self.take(*args, **kwargs)
 
     @Appender(_index_shared_docs["_maybe_cast_slice_bound"])
     def _maybe_cast_slice_bound(self, label, side, kind):

pandas/tests/arrays/categorical/test_algos.py

@@ -177,3 +177,7 @@ def test_take_nd_deprecated(self):
         cat = pd.Categorical(["a", "b", "c"])
         with tm.assert_produces_warning(FutureWarning):
             cat.take_nd([0, 1])
+
+        ci = pd.Index(cat)
+        with tm.assert_produces_warning(FutureWarning):
+            ci.take_nd([0, 1])