TYP: Use Self instead of class-bound TypeVar (generic.py/frame.py/series.py) (#51493)

* TYP: Use Self for type checking

* type frame.py & series.py

* TYP: change Index to Self

Author: topper-123

pandas/core/frame.py

@@ -231,6 +231,7 @@
         ReadBuffer,
         Renamer,
         Scalar,
+        Self,
         SortKind,
         StorageOptions,
         Suffixes,
@@ -2495,7 +2496,7 @@ def _from_arrays(
         index,
         dtype: Dtype | None = None,
         verify_integrity: bool = True,
-    ) -> DataFrame:
+    ) -> Self:
         """
         Create DataFrame from a list of arrays corresponding to the columns.
 
@@ -4597,7 +4598,7 @@ def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
 
         return _eval(expr, inplace=inplace, **kwargs)
 
-    def select_dtypes(self, include=None, exclude=None) -> DataFrame:
+    def select_dtypes(self, include=None, exclude=None) -> Self:
         """
         Return a subset of the DataFrame's columns based on the column dtypes.
 
@@ -5015,7 +5016,7 @@ def align(
         limit: int | None = None,
         fill_axis: Axis = 0,
         broadcast_axis: Axis | None = None,
-    ) -> tuple[DataFrame, NDFrameT]:
+    ) -> tuple[Self, NDFrameT]:
         return super().align(
             other,
             join=join,