BUG: Fix for convert_dtypes with mix of int and string (#32126)

Author: Dr-Irv

doc/source/whatsnew/v1.0.2.rst

@@ -45,6 +45,7 @@ Bug fixes
 
 - Fix bug in :meth:`DataFrame.convert_dtypes` for columns that were already using the ``"string"`` dtype (:issue:`31731`).
 - Fixed bug in setting values using a slice indexer with string dtype (:issue:`31772`)
+- Fix bug in :meth:`Series.convert_dtypes` for series with mix of integers and strings (:issue:`32117`)
 
 .. ---------------------------------------------------------------------------
 

pandas/core/dtypes/cast.py

@@ -1062,11 +1062,6 @@ def convert_dtypes(
         if convert_integer:
             target_int_dtype = "Int64"
 
-            if isinstance(inferred_dtype, str) and (
-                inferred_dtype == "mixed-integer"
-                or inferred_dtype == "mixed-integer-float"
-            ):
-                inferred_dtype = target_int_dtype
             if is_integer_dtype(input_array.dtype) and not is_extension_array_dtype(
                 input_array.dtype
             ):

pandas/tests/series/methods/test_convert_dtypes.py

@@ -81,6 +81,18 @@ class TestSeriesConvertDtypes:
                     ),
                 },
             ),
+            (  # GH32117
+                ["h", "i", 1],
+                np.dtype("O"),
+                {
+                    (
+                        (True, False),
+                        (True, False),
+                        (True, False),
+                        (True, False),
+                    ): np.dtype("O"),
+                },
+            ),
             (
                 [10, np.nan, 20],
                 np.dtype("float"),
@@ -144,11 +156,23 @@ class TestSeriesConvertDtypes:
                 [1, 2.0],
                 object,
                 {
-                    ((True, False), (True, False), (True,), (True, False)): "Int64",
+                    ((True,), (True, False), (True,), (True, False)): "Int64",
                     ((True,), (True, False), (False,), (True, False)): np.dtype(
                         "float"
                     ),
-                    ((False,), (True, False), (False,), (True, False)): np.dtype(
+                    ((False,), (True, False), (True, False), (True, False)): np.dtype(
+                        "object"
+                    ),
+                },
+            ),
+            (
+                [1, 2.5],
+                object,
+                {
+                    ((True,), (True, False), (True, False), (True, False)): np.dtype(
+                        "float"
+                    ),
+                    ((False,), (True, False), (True, False), (True, False)): np.dtype(
                         "object"
                     ),
                 },