GH1398 Remove cast from Index(..., dtype='categorical').array (#1414)

* GH1398 Remove cast from Index(..., dtype='categorical').array

* GH1398 Remove cast from Index(..., dtype='categorical').array

* GH1398 Remove cast from Index(..., dtype='categorical').array

* GH1398 Remove cast from Index(..., dtype='categorical').array

* GH1398 Remove cast from Index(..., dtype='categorical').array

* GH1398 PR Feedback

Author: loicdiridollou

pandas-stubs/core/indexes/category.pyi

@@ -6,6 +6,7 @@ from typing import final
 
 import numpy as np
 from pandas.core import accessor
+from pandas.core.arrays.categorical import Categorical
 from pandas.core.indexes.base import Index
 from pandas.core.indexes.extension import ExtensionIndex
 from typing_extensions import Self
@@ -18,6 +19,8 @@ from pandas._typing import (
 class CategoricalIndex(ExtensionIndex[S1], accessor.PandasDelegate):
     codes: np.ndarray = ...
     categories: Index = ...
+    @property
+    def array(self) -> Categorical: ...  # type: ignore[override] # pyrefly: ignore[bad-override]
     def __new__(
         cls,
         data: Iterable[S1] = ...,

tests/indexes/test_indexes.py

@@ -1531,10 +1531,7 @@ def test_array_property() -> None:
     """Test that Index.array and semantic Index.array return ExtensionArray and its subclasses"""
     # casting due to pandas-dev/pandas-stubs#1383
     check(
-        assert_type(
-            cast("Index[pd.CategoricalDtype]", Index([1], dtype="category")).array,
-            pd.Categorical,
-        ),
+        assert_type(Index([1], dtype="category").array, pd.Categorical),
         pd.Categorical,
         int,
     )