TYP: update EA.view() type annotation to indicate it returns an EA without dtype parameter

Author: jorisvandenbossche

pandas/core/arrays/_mixins.py

@@ -113,6 +113,12 @@ def _validate_scalar(self, value):
 
     # ------------------------------------------------------------------------
 
+    @overload
+    def view(self) -> Self: ...
+
+    @overload
+    def view(self, dtype: Dtype | None = ...) -> ArrayLike: ...
+
     def view(self, dtype: Dtype | None = None) -> ArrayLike:
         # We handle datetime64, datetime64tz, timedelta64, and period
         #  dtypes here. Everything else we pass through to the underlying

pandas/core/arrays/base.py

@@ -1804,6 +1804,12 @@ def copy(self) -> Self:
         """
         raise AbstractMethodError(self)
 
+    @overload
+    def view(self) -> ExtensionArray: ...
+
+    @overload
+    def view(self, dtype: Dtype | None = ...) -> ArrayLike: ...
+
     def view(self, dtype: Dtype | None = None) -> ArrayLike:
         """
         Return a view on the array.

pandas/core/arrays/string_.py

@@ -546,10 +546,10 @@ def _str_map_nan_semantics(
         else:
             return self._str_map_str_or_object(dtype, na_value, arr, f, mask)
 
-    def view(self, dtype: Dtype | None = None) -> ArrayLike:
+    def view(self, dtype: Dtype | None = None) -> Self:
         if dtype is not None:
             raise TypeError("Cannot change data-type for string array.")
-        return super().view(dtype=dtype)
+        return super().view()
 
 
 # error: Definition of "_concat_same_type" in base class "NDArrayBacked" is