Fixed bug, where BooleanDtype columns were converted to Int64

Author: AnnaDaglis

doc/source/whatsnew/v1.0.2.rst

@@ -83,6 +83,7 @@ Bug fixes
 - Fixed bug in setting values using a slice indexer with string dtype (:issue:`31772`)
 - Fixed bug where :meth:`GroupBy.first` and :meth:`GroupBy.last` would raise a ``TypeError`` when groups contained ``pd.NA`` in a column of object dtype (:issue:`32123`)
 - Fix bug in :meth:`Series.convert_dtypes` for series with mix of integers and strings (:issue:`32117`)
+- Fixed bug in :meth:`DataFrame.convert_dtypes`, where ``BooleanDtype`` columns were converted to ``Int64`` (:issue:`32287`)
 
 .. ---------------------------------------------------------------------------
 

pandas/core/dtypes/cast.py

@@ -6,6 +6,7 @@
 
 import numpy as np
 
+import pandas as pd
 from pandas._libs import lib, tslib, tslibs
 from pandas._libs.tslibs import (
     NaT,
@@ -1078,8 +1079,9 @@ def convert_dtypes(
                 inferred_dtype = input_array.dtype
 
         if convert_boolean:
-            if is_bool_dtype(input_array.dtype) and not is_extension_array_dtype(
-                input_array.dtype
+            if is_bool_dtype(input_array.dtype) and (
+                (not is_extension_array_dtype(input_array.dtype))
+                or (input_array.dtype == pd.BooleanDtype())
             ):
                 inferred_dtype = "boolean"
         else:

pandas/tests/series/methods/test_convert_dtypes.py

@@ -279,3 +279,16 @@ def test_convert_string_dtype(self):
         )
         result = df.convert_dtypes()
         tm.assert_frame_equal(df, result)
+
+    def test_convert_bool_dtype(self):
+        # GH32287
+        df = pd.DataFrame([["abc", 123, True]])
+        exp_dtypes = pd.Series([np.object, np.int64, np.bool])
+        tm.assert_series_equal(df.dtypes, exp_dtypes)
+
+        df_1 = df.convert_dtypes()
+        exp_dtypes_1 = pd.Series([pd.StringDtype(), pd.Int64Dtype(), pd.BooleanDtype()])
+        tm.assert_series_equal(df_1.dtypes, exp_dtypes_1)
+
+        df_2 = df_1.convert_dtypes()
+        tm.assert_series_equal(df_2.dtypes, exp_dtypes_1)