TST: GH23452 test reorder_categories() on categorical index (#36648)

Author: fokoid

pandas/tests/indexing/test_categorical.py

@@ -807,3 +807,31 @@ def test_loc_with_non_string_categories(self, idx_values, ordered):
  result.loc[sl, "A"] = ["qux", "qux2"]
  expected = DataFrame({"A": ["qux", "qux2", "baz"]}, index=cat_idx)
  tm.assert_frame_equal(result, expected)
+
+ @pytest.mark.parametrize(
+ "categories",
+ [
+ pytest.param(["a", "b", "c"], id="str"),
+ pytest.param(
+ [pd.Interval(0, 1), pd.Interval(1, 2), pd.Interval(2, 3)],
+ id="pd.Interval",
+ ),
+ ],
+ )
+ def test_reorder_index_with_categories(self, categories):
+ # GH23452
+ df = DataFrame(
+ {"foo": range(len(categories))},
+ index=CategoricalIndex(
+ data=categories, categories=categories, ordered=True
+ ),
+ )
+ df.index = df.index.reorder_categories(df.index.categories[::-1])
+ result = df.sort_index()
+ expected = DataFrame(
+ {"foo": reversed(range(len(categories)))},
+ index=CategoricalIndex(
+ data=categories[::-1], categories=categories[::-1], ordered=True
+ ),
+ )
+ tm.assert_frame_equal(result, expected)