Simplify

Author: TomAugspurger

pandas/core/dtypes/cast.py

@@ -70,8 +70,6 @@
 from pandas.core.dtypes.inference import is_list_like
 from pandas.core.dtypes.missing import isna, notna
 
-import pandas as pd
-
 _int8_max = np.iinfo(np.int8).max
 _int16_max = np.iinfo(np.int16).max
 _int32_max = np.iinfo(np.int32).max
@@ -1051,7 +1049,8 @@ def convert_dtypes(
     dtype
         new dtype
     """
-    if convert_string or convert_integer or convert_boolean:
+    is_extension = is_extension_array_dtype(input_array.dtype)
+    if (convert_string or convert_integer or convert_boolean) and not is_extension:
         try:
             inferred_dtype = lib.infer_dtype(input_array)
         except ValueError:
@@ -1064,9 +1063,7 @@ def convert_dtypes(
         if convert_integer:
             target_int_dtype = "Int64"
 
-            if is_integer_dtype(input_array.dtype) and not is_extension_array_dtype(
-                input_array.dtype
-            ):
+            if is_integer_dtype(input_array.dtype):
                 from pandas.core.arrays.integer import _dtypes
 
                 inferred_dtype = _dtypes.get(input_array.dtype.name, target_int_dtype)
@@ -1080,10 +1077,7 @@ 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))
-                or (input_array.dtype == pd.BooleanDtype())
-            ):
+            if is_bool_dtype(input_array.dtype):
                 inferred_dtype = "boolean"
         else:
             if isinstance(inferred_dtype, str) and inferred_dtype == "boolean":

pandas/tests/series/methods/test_convert_dtypes.py

@@ -282,13 +282,5 @@ def test_convert_string_dtype(self):
 
     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)
+        df = pd.DataFrame({"A": pd.array([True])})
+        tm.assert_frame_equal(df, df.convert_dtypes())