mypy fixup

Author: jbrockmendel

pandas/core/arrays/arrow/array.py

@@ -409,22 +409,22 @@ def _cast_pointwise_result(self, values) -> ArrayLike:
             # workaround for https://github.com/apache/arrow/issues/40620
             result = ArrowExtensionArray._from_sequence(values)
             if pa.types.is_duration(self._pa_array.type):
-                result = result.astype(self.dtype)
+                result = result.astype(self.dtype)  # type: ignore[assignment]
             elif pa.types.is_timestamp(self._pa_array.type):
                 # Try to retain original unit
                 new_dtype = ArrowDtype(pa.duration(self._pa_array.type.unit))
                 try:
-                    result = result.astype(new_dtype)
+                    result = result.astype(new_dtype)  # type: ignore[assignment]
                 except ValueError:
                     pass
             elif pa.types.is_date64(self._pa_array.type):
                 # Try to match unit we get on non-pointwise op
                 dtype = ArrowDtype(pa.duration("ms"))
-                result = result.astype(dtype)
+                result = result.astype(dtype)  # type: ignore[assignment]
             elif pa.types.is_date(self._pa_array.type):
                 # Try to match unit we get on non-pointwise op
                 dtype = ArrowDtype(pa.duration("s"))
-                result = result.astype(dtype)
+                result = result.astype(dtype)  # type: ignore[assignment]
             return result
 
         elif pa.types.is_date(arr.type) and pa.types.is_date(self._pa_array.type):

pandas/core/arrays/masked.py

@@ -154,6 +154,7 @@ def _cast_pointwise_result(self, values) -> ArrayLike:
         lkind = self.dtype.kind
         rkind = result.dtype.kind
         if (lkind in "iu" and rkind in "iu") or (lkind == rkind == "f"):
+            result = cast(BaseMaskedArray, result)
             new_data = maybe_downcast_to_dtype(
                 result._data, dtype=self.dtype.numpy_dtype
             )

pandas/core/arrays/string_.py

@@ -729,7 +729,7 @@ def _cast_pointwise_result(self, values) -> ArrayLike:
         result = super()._cast_pointwise_result(values)
         if isinstance(result.dtype, StringDtype):
             # Ensure we retain our same na_value/storage
-            result = result.astype(self.dtype)
+            result = result.astype(self.dtype)  # type: ignore[call-overload]
         return result
 
     @classmethod

pandas/tests/extension/test_arrow.py

@@ -837,7 +837,9 @@ def _cast_pointwise_result(self, op_name: str, obj, other, pointwise_result):
         elif type(other) is float:
             return expected.astype("float64[pyarrow]")
 
-        orig_pa_type = original_dtype.pyarrow_dtype
+        # error: Item "ExtensionDtype" of "dtype[Any] | ExtensionDtype" has
+        #  no attribute "pyarrow_dtype"
+        orig_pa_type = original_dtype.pyarrow_dtype  # type: ignore[union-attr]
         if not was_frame and isinstance(other, pd.Series):
             # i.e. test_arith_series_with_array
             if not (