stdlib: Improve many __iter__ and constructor methods (#7112)

Author: AlexWaygood

stdlib/_py_abc.pyi

@@ -1,3 +1,4 @@
+from _typeshed import Self
 from typing import Any, NewType, TypeVar
 
 _T = TypeVar("_T")
@@ -7,5 +8,5 @@ _CacheToken = NewType("_CacheToken", int)
 def get_cache_token() -> _CacheToken: ...
 
 class ABCMeta(type):
-    def __new__(__mcls, __name: str, __bases: tuple[type[Any], ...], __namespace: dict[str, Any]) -> ABCMeta: ...
+    def __new__(__mcls: type[Self], __name: str, __bases: tuple[type[Any], ...], __namespace: dict[str, Any]) -> Self: ...
     def register(cls, subclass: type[_T]) -> type[_T]: ...

stdlib/builtins.pyi

@@ -964,7 +964,7 @@ class frozenset(AbstractSet[_T_co], Generic[_T_co]):
 
 class enumerate(Iterator[tuple[int, _T]], Generic[_T]):
     def __init__(self, iterable: Iterable[_T], start: int = ...) -> None: ...
-    def __iter__(self) -> Iterator[tuple[int, _T]]: ...
+    def __iter__(self: Self) -> Self: ...
     def __next__(self) -> tuple[int, _T]: ...
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, __item: Any) -> GenericAlias: ...
@@ -1095,7 +1095,7 @@ class filter(Iterator[_T], Generic[_T]):
     def __init__(self, __function: Callable[[_S], TypeGuard[_T]], __iterable: Iterable[_S]) -> None: ...
     @overload
     def __init__(self, __function: Callable[[_T], Any], __iterable: Iterable[_T]) -> None: ...
-    def __iter__(self) -> Iterator[_T]: ...
+    def __iter__(self: Self) -> Self: ...
     def __next__(self) -> _T: ...
 
 def format(__value: object, __format_spec: str = ...) -> str: ...  # TODO unicode
@@ -1186,7 +1186,7 @@ class map(Iterator[_S], Generic[_S]):
         __iter6: Iterable[Any],
         *iterables: Iterable[Any],
     ) -> None: ...
-    def __iter__(self) -> Iterator[_S]: ...
+    def __iter__(self: Self) -> Self: ...
     def __next__(self) -> _S: ...
 
 @overload
@@ -1699,7 +1699,7 @@ if sys.version_info >= (3, 11):
     _SplitCondition = type[BaseException] | tuple[type[BaseException], ...] | Callable[[BaseException], bool]
 
     class BaseExceptionGroup(BaseException):
-        def __new__(cls, __message: str, __exceptions: Sequence[BaseException]) -> BaseExceptionGroup | ExceptionGroup: ...
+        def __new__(cls: type[Self], __message: str, __exceptions: Sequence[BaseException]) -> Self: ...
         @property
         def message(self) -> str: ...
         @property
@@ -1709,6 +1709,6 @@ if sys.version_info >= (3, 11):
         def derive(self: Self, __excs: Sequence[BaseException]) -> Self: ...
 
     class ExceptionGroup(BaseExceptionGroup, Exception):
-        def __new__(cls, __message: str, __exceptions: Sequence[Exception]) -> ExceptionGroup: ...
+        def __new__(cls: type[Self], __message: str, __exceptions: Sequence[Exception]) -> Self: ...
         @property
         def exceptions(self) -> tuple[Exception, ...]: ...

stdlib/decimal.pyi

@@ -52,7 +52,7 @@ def localcontext(ctx: Context | None = ...) -> _ContextManager: ...
 class Decimal:
     def __new__(cls: type[Self], value: _DecimalNew = ..., context: Context | None = ...) -> Self: ...
     @classmethod
-    def from_float(cls, __f: float) -> Decimal: ...
+    def from_float(cls: type[Self], __f: float) -> Self: ...
     def __bool__(self) -> bool: ...
     def compare(self, other: _Decimal, context: Context | None = ...) -> Decimal: ...
     def __hash__(self) -> int: ...

stdlib/dis.pyi

@@ -1,5 +1,6 @@
 import sys
 import types
+from _typeshed import Self
 from opcode import *  # `dis` re-exports it as a part of public API
 from typing import IO, Any, Callable, Iterator, NamedTuple, Union
 
@@ -54,7 +55,7 @@ class Bytecode:
     def info(self) -> str: ...
     def dis(self) -> str: ...
     @classmethod
-    def from_traceback(cls, tb: types.TracebackType) -> Bytecode: ...
+    def from_traceback(cls: type[Self], tb: types.TracebackType) -> Self: ...
 
 COMPILER_FLAG_NAMES: dict[int, str]
 

stdlib/email/headerregistry.pyi

@@ -1,5 +1,6 @@
 import sys
 import types
+from _typeshed import Self
 from collections.abc import Iterable, Mapping
 from datetime import datetime as _datetime
 from email._header_value_parser import (
@@ -23,7 +24,7 @@ class BaseHeader(str):
     def name(self) -> str: ...
     @property
     def defects(self) -> tuple[MessageDefect, ...]: ...
-    def __new__(cls, name: str, value: Any) -> BaseHeader: ...
+    def __new__(cls: type[Self], name: str, value: Any) -> Self: ...
     def init(self, name: str, *, parse_tree: TokenList, defects: Iterable[MessageDefect]) -> None: ...
     def fold(self, *, policy: Policy) -> str: ...
 

stdlib/fractions.pyi

@@ -25,9 +25,9 @@ class Fraction(Rational):
     @overload
     def __new__(cls: type[Self], __value: float | Decimal | str, *, _normalize: bool = ...) -> Self: ...
     @classmethod
-    def from_float(cls, f: float) -> Fraction: ...
+    def from_float(cls: type[Self], f: float) -> Self: ...
     @classmethod
-    def from_decimal(cls, dec: Decimal) -> Fraction: ...
+    def from_decimal(cls: type[Self], dec: Decimal) -> Self: ...
     def limit_denominator(self, max_denominator: int = ...) -> Fraction: ...
     if sys.version_info >= (3, 8):
         def as_integer_ratio(self) -> tuple[int, int]: ...

stdlib/sqlite3/dbapi2.pyi

@@ -204,7 +204,7 @@ class Cursor(Iterator[Any]):
     def fetchone(self) -> Any: ...
     def setinputsizes(self, __sizes: object) -> None: ...  # does nothing
     def setoutputsize(self, __size: object, __column: object = ...) -> None: ...  # does nothing
-    def __iter__(self) -> Cursor: ...
+    def __iter__(self: Self) -> Self: ...
     def __next__(self) -> Any: ...
 
 class DataError(DatabaseError): ...

stdlib/tarfile.pyi

@@ -2,6 +2,7 @@ import bz2
 import io
 import sys
 from _typeshed import Self, StrOrBytesPath, StrPath
+from builtins import type as Type  # alias to avoid name clashes with fields named "type"
 from collections.abc import Callable, Iterable, Iterator, Mapping
 from gzip import _ReadableFileobj as _GzipReadableFileobj, _WritableFileobj as _GzipWritableFileobj
 from types import TracebackType
@@ -339,9 +340,9 @@ class TarInfo:
     pax_headers: Mapping[str, str]
     def __init__(self, name: str = ...) -> None: ...
     @classmethod
-    def frombuf(cls, buf: bytes, encoding: str, errors: str) -> TarInfo: ...
+    def frombuf(cls: Type[Self], buf: bytes, encoding: str, errors: str) -> Self: ...
     @classmethod
-    def fromtarfile(cls, tarfile: TarFile) -> TarInfo: ...
+    def fromtarfile(cls: Type[Self], tarfile: TarFile) -> Self: ...
     @property
     def linkpath(self) -> str: ...
     @linkpath.setter

stdlib/traceback.pyi

@@ -1,5 +1,5 @@
 import sys
-from _typeshed import SupportsWrite
+from _typeshed import Self, SupportsWrite
 from types import FrameType, TracebackType
 from typing import IO, Any, Generator, Iterable, Iterator, Mapping, Optional, overload
 
@@ -98,14 +98,14 @@ class TracebackException:
         ) -> None: ...
         @classmethod
         def from_exception(
-            cls,
+            cls: type[Self],
             exc: BaseException,
             *,
             limit: int | None = ...,
             lookup_lines: bool = ...,
             capture_locals: bool = ...,
             compact: bool = ...,
-        ) -> TracebackException: ...
+        ) -> Self: ...
     else:
         def __init__(
             self,
@@ -120,8 +120,8 @@ class TracebackException:
         ) -> None: ...
         @classmethod
         def from_exception(
-            cls, exc: BaseException, *, limit: int | None = ..., lookup_lines: bool = ..., capture_locals: bool = ...
-        ) -> TracebackException: ...
+            cls: type[Self], exc: BaseException, *, limit: int | None = ..., lookup_lines: bool = ..., capture_locals: bool = ...
+        ) -> Self: ...
 
     def format(self, *, chain: bool = ...) -> Generator[str, None, None]: ...
     def format_exception_only(self) -> Generator[str, None, None]: ...

stdlib/unittest/mock.pyi

@@ -1,4 +1,5 @@
 import sys
+from _typeshed import Self
 from typing import Any, Awaitable, Callable, Generic, Iterable, Mapping, Sequence, TypeVar, overload
 from typing_extensions import Literal
 
@@ -76,8 +77,13 @@ DEFAULT: Any
 
 class _Call(tuple[Any, ...]):
     def __new__(
-        cls, value: Any = ..., name: Any | None = ..., parent: Any | None = ..., two: bool = ..., from_kall: bool = ...
-    ) -> Any: ...
+        cls: type[Self],
+        value: Any = ...,
+        name: Any | None = ...,
+        parent: Any | None = ...,
+        two: bool = ...,
+        from_kall: bool = ...,
+    ) -> Self: ...
     name: Any
     parent: Any
     from_kall: Any
@@ -105,7 +111,7 @@ class Base:
     def __init__(self, *args: Any, **kwargs: Any) -> None: ...
 
 class NonCallableMock(Base, Any):
-    def __new__(__cls, *args: Any, **kw: Any) -> NonCallableMock: ...
+    def __new__(__cls: type[Self], *args: Any, **kw: Any) -> Self: ...
     def __init__(
         self,
         spec: list[str] | object | type[object] | None = ...,