Replace __init__ with __new__ in builtins and types (#10761)

stdlib/builtins.pyi

@@ -867,7 +867,7 @@ class memoryview(Sequence[int]):
     def contiguous(self) -> bool: ...
     @property
     def nbytes(self) -> int: ...
-    def __init__(self, obj: ReadableBuffer) -> None: ...
+    def __new__(cls, obj: ReadableBuffer) -> Self: ...
     def __enter__(self) -> Self: ...
     def __exit__(
         self, __exc_type: type[BaseException] | None, __exc_val: BaseException | None, __exc_tb: TracebackType | None
@@ -946,9 +946,9 @@ class slice:
     @property
     def stop(self) -> Any: ...
     @overload
-    def __init__(self, __stop: Any) -> None: ...
+    def __new__(cls, __stop: Any) -> Self: ...
     @overload
-    def __init__(self, __start: Any, __stop: Any, __step: Any = ...) -> None: ...
+    def __new__(cls, __start: Any, __stop: Any, __step: Any = ...) -> Self: ...
     def __eq__(self, __value: object) -> bool: ...
     __hash__: ClassVar[None]  # type: ignore[assignment]
     def indices(self, __len: SupportsIndex) -> tuple[int, int, int]: ...
@@ -1203,7 +1203,7 @@ class frozenset(AbstractSet[_T_co], Generic[_T_co]):
         def __class_getitem__(cls, __item: Any) -> GenericAlias: ...
 
 class enumerate(Iterator[tuple[int, _T]], Generic[_T]):
-    def __init__(self, iterable: Iterable[_T], start: int = ...) -> None: ...
+    def __new__(cls, iterable: Iterable[_T], start: int = ...) -> Self: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> tuple[int, _T]: ...
     if sys.version_info >= (3, 9):
@@ -1218,9 +1218,9 @@ class range(Sequence[int]):
     @property
     def step(self) -> int: ...
     @overload
-    def __init__(self, __stop: SupportsIndex) -> None: ...
+    def __new__(cls, __stop: SupportsIndex) -> Self: ...
     @overload
-    def __init__(self, __start: SupportsIndex, __stop: SupportsIndex, __step: SupportsIndex = ...) -> None: ...
+    def __new__(cls, __start: SupportsIndex, __stop: SupportsIndex, __step: SupportsIndex = ...) -> Self: ...
     def count(self, __value: int) -> int: ...
     def index(self, __value: int) -> int: ...  # type: ignore[override]
     def __len__(self) -> int: ...
@@ -1413,11 +1413,11 @@ def exit(code: sys._ExitCode = None) -> NoReturn: ...
 
 class filter(Iterator[_T], Generic[_T]):
     @overload
-    def __init__(self, __function: None, __iterable: Iterable[_T | None]) -> None: ...
+    def __new__(cls, __function: None, __iterable: Iterable[_T | None]) -> Self: ...
     @overload
-    def __init__(self, __function: Callable[[_S], TypeGuard[_T]], __iterable: Iterable[_S]) -> None: ...
+    def __new__(cls, __function: Callable[[_S], TypeGuard[_T]], __iterable: Iterable[_S]) -> Self: ...
     @overload
-    def __init__(self, __function: Callable[[_T], Any], __iterable: Iterable[_T]) -> None: ...
+    def __new__(cls, __function: Callable[[_T], Any], __iterable: Iterable[_T]) -> Self: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> _T: ...
 
@@ -1472,35 +1472,35 @@ def locals() -> dict[str, Any]: ...
 
 class map(Iterator[_S], Generic[_S]):
     @overload
-    def __init__(self, __func: Callable[[_T1], _S], __iter1: Iterable[_T1]) -> None: ...
+    def __new__(cls, __func: Callable[[_T1], _S], __iter1: Iterable[_T1]) -> Self: ...
     @overload
-    def __init__(self, __func: Callable[[_T1, _T2], _S], __iter1: Iterable[_T1], __iter2: Iterable[_T2]) -> None: ...
+    def __new__(cls, __func: Callable[[_T1, _T2], _S], __iter1: Iterable[_T1], __iter2: Iterable[_T2]) -> Self: ...
     @overload
-    def __init__(
-        self, __func: Callable[[_T1, _T2, _T3], _S], __iter1: Iterable[_T1], __iter2: Iterable[_T2], __iter3: Iterable[_T3]
-    ) -> None: ...
+    def __new__(
+        cls, __func: Callable[[_T1, _T2, _T3], _S], __iter1: Iterable[_T1], __iter2: Iterable[_T2], __iter3: Iterable[_T3]
+    ) -> Self: ...
     @overload
-    def __init__(
-        self,
+    def __new__(
+        cls,
         __func: Callable[[_T1, _T2, _T3, _T4], _S],
         __iter1: Iterable[_T1],
         __iter2: Iterable[_T2],
         __iter3: Iterable[_T3],
         __iter4: Iterable[_T4],
-    ) -> None: ...
+    ) -> Self: ...
     @overload
-    def __init__(
-        self,
+    def __new__(
+        cls,
         __func: Callable[[_T1, _T2, _T3, _T4, _T5], _S],
         __iter1: Iterable[_T1],
         __iter2: Iterable[_T2],
         __iter3: Iterable[_T3],
         __iter4: Iterable[_T4],
         __iter5: Iterable[_T5],
-    ) -> None: ...
+    ) -> Self: ...
     @overload
-    def __init__(
-        self,
+    def __new__(
+        cls,
         __func: Callable[..., _S],
         __iter1: Iterable[Any],
         __iter2: Iterable[Any],
@@ -1509,7 +1509,7 @@ class map(Iterator[_S], Generic[_S]):
         __iter5: Iterable[Any],
         __iter6: Iterable[Any],
         *iterables: Iterable[Any],
-    ) -> None: ...
+    ) -> Self: ...
     def __iter__(self) -> Self: ...
     def __next__(self) -> _S: ...
 

stdlib/types.pyi

@@ -69,7 +69,7 @@ _VT_co = TypeVar("_VT_co", covariant=True)
 @final
 class _Cell:
     if sys.version_info >= (3, 8):
-        def __init__(self, __contents: object = ...) -> None: ...
+        def __new__(cls, __contents: object = ...) -> Self: ...
 
     def __eq__(self, __value: object) -> bool: ...
     __hash__: ClassVar[None]  # type: ignore[assignment]
@@ -96,14 +96,14 @@ class FunctionType:
         __type_params__: tuple[TypeVar | ParamSpec | TypeVarTuple, ...]
 
     __module__: str
-    def __init__(
-        self,
+    def __new__(
+        cls,
         code: CodeType,
         globals: dict[str, Any],
         name: str | None = ...,
         argdefs: tuple[object, ...] | None = ...,
         closure: tuple[_Cell, ...] | None = ...,
-    ) -> None: ...
+    ) -> Self: ...
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
     @overload
     def __get__(self, __instance: None, __owner: type) -> FunctionType: ...
@@ -162,8 +162,8 @@ class CodeType:
         def co_positions(self) -> Iterable[tuple[int | None, int | None, int | None, int | None]]: ...
 
     if sys.version_info >= (3, 11):
-        def __init__(
-            self,
+        def __new__(
+            cls,
             __argcount: int,
             __posonlyargcount: int,
             __kwonlyargcount: int,
@@ -182,10 +182,10 @@ class CodeType:
             __exceptiontable: bytes,
             __freevars: tuple[str, ...] = ...,
             __cellvars: tuple[str, ...] = ...,
-        ) -> None: ...
+        ) -> Self: ...
     elif sys.version_info >= (3, 10):
-        def __init__(
-            self,
+        def __new__(
+            cls,
             __argcount: int,
             __posonlyargcount: int,
             __kwonlyargcount: int,
@@ -202,10 +202,10 @@ class CodeType:
             __linetable: bytes,
             __freevars: tuple[str, ...] = ...,
             __cellvars: tuple[str, ...] = ...,
-        ) -> None: ...
+        ) -> Self: ...
     elif sys.version_info >= (3, 8):
-        def __init__(
-            self,
+        def __new__(
+            cls,
             __argcount: int,
             __posonlyargcount: int,
             __kwonlyargcount: int,
@@ -222,10 +222,10 @@ class CodeType:
             __lnotab: bytes,
             __freevars: tuple[str, ...] = ...,
             __cellvars: tuple[str, ...] = ...,
-        ) -> None: ...
+        ) -> Self: ...
     else:
-        def __init__(
-            self,
+        def __new__(
+            cls,
             __argcount: int,
             __kwonlyargcount: int,
             __nlocals: int,
@@ -241,7 +241,7 @@ class CodeType:
             __lnotab: bytes,
             __freevars: tuple[str, ...] = ...,
             __cellvars: tuple[str, ...] = ...,
-        ) -> None: ...
+        ) -> Self: ...
     if sys.version_info >= (3, 11):
         def replace(
             self,
@@ -311,7 +311,7 @@ class CodeType:
 @final
 class MappingProxyType(Mapping[_KT, _VT_co], Generic[_KT, _VT_co]):
     __hash__: ClassVar[None]  # type: ignore[assignment]
-    def __init__(self, mapping: SupportsKeysAndGetItem[_KT, _VT_co]) -> None: ...
+    def __new__(cls, mapping: SupportsKeysAndGetItem[_KT, _VT_co]) -> Self: ...
     def __getitem__(self, __key: _KT) -> _VT_co: ...
     def __iter__(self) -> Iterator[_KT]: ...
     def __len__(self) -> int: ...
@@ -444,7 +444,7 @@ class MethodType:
     def __name__(self) -> str: ...  # inherited from the added function
     @property
     def __qualname__(self) -> str: ...  # inherited from the added function
-    def __init__(self, __func: Callable[..., Any], __obj: object) -> None: ...
+    def __new__(cls, __func: Callable[..., Any], __obj: object) -> Self: ...
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
     def __eq__(self, __value: object) -> bool: ...
     def __hash__(self) -> int: ...
@@ -513,7 +513,7 @@ class ClassMethodDescriptorType:
 
 @final
 class TracebackType:
-    def __init__(self, tb_next: TracebackType | None, tb_frame: FrameType, tb_lasti: int, tb_lineno: int) -> None: ...
+    def __new__(cls, tb_next: TracebackType | None, tb_frame: FrameType, tb_lasti: int, tb_lineno: int) -> Self: ...
     tb_next: TracebackType | None
     # the rest are read-only even in 3.7
     @property
@@ -610,7 +610,7 @@ if sys.version_info >= (3, 9):
         def __args__(self) -> tuple[Any, ...]: ...
         @property
         def __parameters__(self) -> tuple[Any, ...]: ...
-        def __init__(self, origin: type, args: Any) -> None: ...
+        def __new__(cls, origin: type, args: Any) -> Self: ...
         def __getitem__(self, __typeargs: Any) -> GenericAlias: ...
         def __eq__(self, __value: object) -> bool: ...
         def __hash__(self) -> int: ...