BUG: AttributeError: 'BooleanArray' object has no attribute 'sum' while infer types #44079

doc/source/user_guide/timeseries.rst

@@ -2074,7 +2074,7 @@ The ``period`` dtype can be used in ``.astype(...)``. It allows one to change th
    pi.astype("period[D]")
 
    # convert to DatetimeIndex
-   pi.astype("datetime64[ns]")
+   pi.to_timestamp()
 
    # convert to PeriodIndex
    dti = pd.date_range("2011-01-01", freq="M", periods=3)

pandas/io/parsers/base_parser.py

@@ -700,7 +700,7 @@ def _infer_types(self, values, na_values, try_num_bool=True):
             # error: Argument 2 to "isin" has incompatible type "List[Any]"; expected
             # "Union[Union[ExtensionArray, ndarray], Index, Series]"
             mask = algorithms.isin(values, list(na_values))  # type: ignore[arg-type]
-            na_count = mask.sum()
+            na_count = mask.astype("uint8").sum()
             if na_count > 0:
                 if is_integer_dtype(values):
                     values = values.astype(np.float64)

pandas/tests/io/parser/test_index_col.py

@@ -297,3 +297,24 @@ def test_multiindex_columns_index_col_with_data(all_parsers):
         index=Index(["data"]),
     )
     tm.assert_frame_equal(result, expected)
+
+
+@skip_pyarrow
+def test_infer_types_boolean_sum(all_parsers):
+    # GH#44079
+    parser = all_parsers
+    result = parser.read_csv(
+        StringIO("0,1"),
+        names=["a", "b"],
+        index_col=["a"],
+        dtype={"a": "UInt8"},
+    )
+    expected = DataFrame(
+        data={
+            "a": [
+                0,
+            ],
+            "b": [1],
+        }
+    ).set_index("a")
+    tm.assert_frame_equal(result, expected, check_index_type=False)