suggestions from code review

pandas-dev · mroeschke · Apr 25, 2023 · Mar 11, 2023 · Mar 11, 2023 · Mar 11, 2023
commit 1d221b1b8962e1c8851c66f0d96d2be9a5b9ece7
diff --git a/pandas/tests/indexing/multiindex/test_multiindex.py b/pandas/tests/indexing/multiindex/test_multiindex.py
@@ -4,6 +4,8 @@
 import pandas._libs.index as _index
 from pandas.errors import PerformanceWarning
 
+from pandas.core.dtypes.common import is_categorical_dtype
+
 import pandas as pd
 from pandas import (
     DataFrame,
@@ -12,6 +14,7 @@
     Series,
 )
 import pandas._testing as tm
+from pandas.core.arrays.boolean import BooleanDtype
 
 
 class TestMultiIndexBasic:
@@ -211,7 +214,8 @@ def test_multiindex_dtype_preservation(self):
         # GH51261
         columns = MultiIndex.from_tuples([("A", "B")], names=["lvl1", "lvl2"])
         df = DataFrame(["value"], columns=columns).astype("category")
-        assert (df["A"].dtypes == "category").all()
+        df_no_multiindex = df["A"]
+        assert is_categorical_dtype(df_no_multiindex["B"])
-        assert is_categorical_dtype(df_no_multiindex["B"])
+        assert isinstance(df_no_multiindex["B"].dtype, CategoricalDtype)
-        assert is_categorical_dtype(df_no_multiindex["B"])
+        assert isinstance(df_no_multiindex["B"].dtype, CategoricalDtype)
 
         # geopandas 1763 analogue
         df = DataFrame(
@@ -222,4 +226,4 @@ def test_multiindex_dtype_preservation(self):
                 ["x", "y"],
             ],
         ).assign(bools=Series([True, False], dtype="boolean"))
-        assert df["bools"].dtype == "boolean"
+        assert isinstance(df["bools"].dtype, BooleanDtype)