simplify

Author: MarcoGorelli

pandas-stubs/_typing.pyi

@@ -824,30 +824,8 @@ MaskType: TypeAlias = Series[bool] | np_ndarray_bool | list[bool]
 
 # Scratch types for generics
 
-S1 = TypeVar(
-    "S1",
-    bound=str
-    | bytes
-    | datetime.date
-    | datetime.time
-    | bool
-    | int
-    | float
-    | complex
-    | Dtype
-    | datetime.datetime  # includes pd.Timestamp
-    | datetime.timedelta  # includes pd.Timedelta
-    | Period
-    | Interval
-    | CategoricalDtype
-    | BaseOffset
-    | list[str],
-    default=Any,
-)
-
-S2 = TypeVar(
-    "S2",
-    bound=str
+SeriesDType: TypeAlias = (
+    str
     | bytes
     | datetime.date
     | datetime.time
@@ -862,8 +840,11 @@ S2 = TypeVar(
     | Interval
     | CategoricalDtype
     | BaseOffset
-    | list[str],
+    | list[str]
 )
+S1 = TypeVar("S1", bound=SeriesDType, default=Any)
+# Like S1, but without `default=Any`.
+S2 = TypeVar("S2", bound=SeriesDType)
 
 IndexingInt: TypeAlias = (
     int | np.int_ | np.integer | np.unsignedinteger | np.signedinteger | np.int8

pandas-stubs/core/frame.pyi

@@ -1391,6 +1391,7 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
     @overload
     def apply(
         self,
+        # Use S2 (TypeVar without `default=Any`) instead of S1 due to https://github.com/python/mypy/issues/19182.
         f: Callable[..., S2 | NAType],
         axis: AxisIndex = ...,
         raw: _bool = ...,
@@ -1415,6 +1416,7 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
     @overload
     def apply(
         self,
+        # Use S2 (TypeVar without `default=Any`) instead of S1 due to https://github.com/python/mypy/issues/19182.
         f: Callable[..., S2 | NAType],
         axis: Axis = ...,
         raw: _bool = ...,
@@ -1476,6 +1478,7 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
     @overload
     def apply(
         self,
+        # Use S2 (TypeVar without `default=Any`) instead of S1 due to https://github.com/python/mypy/issues/19182.
         f: Callable[..., S2 | NAType],
         raw: _bool = ...,
         result_type: None = ...,