Add missing methods to collections classes (#6388)

Co-authored-by: Akuli <akuviljanen17@gmail.com>

stdlib/collections/__init__.pyi

@@ -4,6 +4,9 @@ from _typeshed import Self
 from typing import Any, Dict, Generic, NoReturn, Tuple, Type, TypeVar, overload
 from typing_extensions import final
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 if sys.version_info >= (3, 10):
     from typing import Callable, Iterable, Iterator, Mapping, MutableMapping, MutableSequence, Reversible, Sequence
 else:
@@ -126,6 +129,8 @@ class UserString(Sequence[str]):
     def isspace(self) -> bool: ...
     def istitle(self) -> bool: ...
     def isupper(self) -> bool: ...
+    if sys.version_info >= (3, 7):
+        def isascii(self) -> bool: ...
     def join(self, seq: Iterable[str]) -> str: ...
     def ljust(self: _UserStringT, width: int, *args: Any) -> _UserStringT: ...
     def lower(self: _UserStringT) -> _UserStringT: ...
@@ -200,6 +205,8 @@ class deque(MutableSequence[_T], Generic[_T]):
     def __add__(self: _S, __other: _S) -> _S: ...
     def __mul__(self: _S, __other: int) -> _S: ...
     def __imul__(self: _S, __other: int) -> _S: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, __item: Any) -> GenericAlias: ...
 
 class Counter(Dict[_T, int], Generic[_T]):
     @overload
@@ -240,6 +247,8 @@ class Counter(Dict[_T, int], Generic[_T]):
     def __isub__(self, other: Counter[_T]) -> Counter[_T]: ...
     def __iand__(self, other: Counter[_T]) -> Counter[_T]: ...
     def __ior__(self, other: Counter[_T]) -> Counter[_T]: ...  # type: ignore[override]
+    if sys.version_info >= (3, 10):
+        def total(self) -> int: ...
 
 @final
 class _OrderedDictKeysView(dict_keys[_KT_co, _VT_co], Reversible[_KT_co]):  # type: ignore[misc]
@@ -301,3 +310,10 @@ class ChainMap(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
     def pop(self, key: _KT) -> _VT: ...
     @overload
     def pop(self, key: _KT, default: _VT | _T = ...) -> _VT | _T: ...
+    def copy(self: Self) -> Self: ...
+    @classmethod
+    @overload
+    def fromkeys(cls, iterable: Iterable[_T], __value: None = ...) -> ChainMap[_T, Any | None]: ...
+    @classmethod
+    @overload
+    def fromkeys(cls, __iterable: Iterable[_T], __value: _S) -> ChainMap[_T, _S]: ...

tests/stubtest_allowlists/py3_common.txt

@@ -51,6 +51,7 @@ codecs.CodecInfo.streamreader
 codecs.CodecInfo.streamwriter
 # Coroutine and Generator properties are added programmatically
 collections.ChainMap.get  # Adding None to the underlying Mapping Union messed up mypy
+collections.ChainMap.fromkeys  # Runtime has *args which can really only be one argument
 # Coroutine and Generator properties are added programmatically
 collections.abc.Coroutine.cr_await
 collections.abc.Coroutine.cr_code