# Utility types for typeshed # # See the README.md file in this directory for more information. import sys from collections.abc import Awaitable, Callable, Iterable, Iterator, Sequence, Set as AbstractSet, Sized from dataclasses import Field from os import PathLike from types import FrameType, TracebackType from typing import ( Any, AnyStr, ClassVar, Final, Generic, Literal, Protocol, SupportsFloat, SupportsIndex, SupportsInt, TypeVar, final, overload, ) from typing_extensions import Buffer, LiteralString, Self as _Self, TypeAlias _KT = TypeVar("_KT") _KT_co = TypeVar("_KT_co", covariant=True) _KT_contra = TypeVar("_KT_contra", contravariant=True) _VT = TypeVar("_VT") _VT_co = TypeVar("_VT_co", covariant=True) _T = TypeVar("_T") _T_co = TypeVar("_T_co", covariant=True) _T_contra = TypeVar("_T_contra", contravariant=True) # Alternative to `typing_extensions.Self`, exclusively for use with `__new__` # in metaclasses: # def __new__(cls: type[Self], ...) -> Self: ... # In other cases, use `typing_extensions.Self`. Self = TypeVar("Self") # noqa: Y001 # covariant version of typing.AnyStr, useful for protocols AnyStr_co = TypeVar("AnyStr_co", str, bytes, covariant=True) # noqa: Y001 # For partially known annotations. Usually, fields where type annotations # haven't been added are left unannotated, but in some situations this # isn't possible or a type is already partially known. In cases like these, # use Incomplete instead of Any as a marker. For example, use # "Incomplete | None" instead of "Any | None". Incomplete: TypeAlias = Any # stable # To describe a function parameter that is unused and will work with anything. Unused: TypeAlias = object # stable # Marker for return types that include None, but where forcing the user to # check for None can be detrimental. Sometimes called "the Any trick". See # https://typing.python.org/en/latest/guides/writing_stubs.html#the-any-trick # for more information. MaybeNone: TypeAlias = Any # stable # Used to mark arguments that default to a sentinel value. This prevents # stubtest from complaining about the default value not matching. # # def foo(x: int | None = sentinel) -> None: ... # # In cases where the sentinel object is exported and can be used by user code, # a construct like this is better: # # _SentinelType = NewType("_SentinelType", object) # does not exist at runtime # sentinel: Final[_SentinelType] # def foo(x: int | None | _SentinelType = ...) -> None: ... sentinel: Any # stable # stable class IdentityFunction(Protocol): def __call__(self, x: _T, /) -> _T: ... # stable class SupportsNext(Protocol[_T_co]): def __next__(self) -> _T_co: ... # stable class SupportsAnext(Protocol[_T_co]): def __anext__(self) -> Awaitable[_T_co]: ... class SupportsBool(Protocol): def __bool__(self) -> bool: ... # Comparison protocols class SupportsDunderLT(Protocol[_T_contra]): def __lt__(self, other: _T_contra, /) -> SupportsBool: ... class SupportsDunderGT(Protocol[_T_contra]): def __gt__(self, other: _T_contra, /) -> SupportsBool: ... class SupportsDunderLE(Protocol[_T_contra]): def __le__(self, other: _T_contra, /) -> SupportsBool: ... class SupportsDunderGE(Protocol[_T_contra]): def __ge__(self, other: _T_contra, /) -> SupportsBool: ... class SupportsAllComparisons( SupportsDunderLT[Any], SupportsDunderGT[Any], SupportsDunderLE[Any], SupportsDunderGE[Any], Protocol ): ... SupportsRichComparison: TypeAlias = SupportsDunderLT[Any] | SupportsDunderGT[Any] SupportsRichComparisonT = TypeVar("SupportsRichComparisonT", bound=SupportsRichComparison) # noqa: Y001 # Dunder protocols class SupportsAdd(Protocol[_T_contra, _T_co]): def __add__(self, x: _T_contra, /) -> _T_co: ... class SupportsRAdd(Protocol[_T_contra, _T_co]): def __radd__(self, x: _T_contra, /) -> _T_co: ... class SupportsSub(Protocol[_T_contra, _T_co]): def __sub__(self, x: _T_contra, /) -> _T_co: ... class SupportsRSub(Protocol[_T_contra, _T_co]): def __rsub__(self, x: _T_contra, /) -> _T_co: ... class SupportsMul(Protocol[_T_contra, _T_co]): def __mul__(self, x: _T_contra, /) -> _T_co: ... class SupportsRMul(Protocol[_T_contra, _T_co]): def __rmul__(self, x: _T_contra, /) -> _T_co: ... class SupportsMod(Protocol[_T_contra, _T_co]): def __mod__(self, other: _T_contra, /) -> _T_co: ... class SupportsRMod(Protocol[_T_contra, _T_co]): def __rmod__(self, other: _T_contra, /) -> _T_co: ... class SupportsDivMod(Protocol[_T_contra, _T_co]): def __divmod__(self, other: _T_contra, /) -> _T_co: ... class SupportsRDivMod(Protocol[_T_contra, _T_co]): def __rdivmod__(self, other: _T_contra, /) -> _T_co: ... # This protocol is generic over the iterator type, while Iterable is # generic over the type that is iterated over. class SupportsIter(Protocol[_T_co]): def __iter__(self) -> _T_co: ... # This protocol is generic over the iterator type, while AsyncIterable is # generic over the type that is iterated over. class SupportsAiter(Protocol[_T_co]): def __aiter__(self) -> _T_co: ... class SupportsLen(Protocol): def __len__(self) -> int: ... class SupportsLenAndGetItem(Protocol[_T_co]): def __len__(self) -> int: ... def __getitem__(self, k: int, /) -> _T_co: ... class SupportsTrunc(Protocol): def __trunc__(self) -> int: ... # Mapping-like protocols # stable class SupportsItems(Protocol[_KT_co, _VT_co]): def items(self) -> AbstractSet[tuple[_KT_co, _VT_co]]: ... # stable class SupportsKeysAndGetItem(Protocol[_KT, _VT_co]): def keys(self) -> Iterable[_KT]: ... def __getitem__(self, key: _KT, /) -> _VT_co: ... # stable class SupportsGetItem(Protocol[_KT_contra, _VT_co]): def __getitem__(self, key: _KT_contra, /) -> _VT_co: ... # stable class SupportsContainsAndGetItem(Protocol[_KT_contra, _VT_co]): def __contains__(self, x: Any, /) -> bool: ... def __getitem__(self, key: _KT_contra, /) -> _VT_co: ... # stable class SupportsItemAccess(Protocol[_KT_contra, _VT]): def __contains__(self, x: Any, /) -> bool: ... def __getitem__(self, key: _KT_contra, /) -> _VT: ... def __setitem__(self, key: _KT_contra, value: _VT, /) -> None: ... def __delitem__(self, key: _KT_contra, /) -> None: ... StrPath: TypeAlias = str | PathLike[str] # stable BytesPath: TypeAlias = bytes | PathLike[bytes] # stable GenericPath: TypeAlias = AnyStr | PathLike[AnyStr] StrOrBytesPath: TypeAlias = str | bytes | PathLike[str] | PathLike[bytes] # stable OpenTextModeUpdating: TypeAlias = Literal[ "r+", "+r", "rt+", "r+t", "+rt", "tr+", "t+r", "+tr", "w+", "+w", "wt+", "w+t", "+wt", "tw+", "t+w", "+tw", "a+", "+a", "at+", "a+t", "+at", "ta+", "t+a", "+ta", "x+", "+x", "xt+", "x+t", "+xt", "tx+", "t+x", "+tx", ] OpenTextModeWriting: TypeAlias = Literal["w", "wt", "tw", "a", "at", "ta", "x", "xt", "tx"] OpenTextModeReading: TypeAlias = Literal["r", "rt", "tr", "U", "rU", "Ur", "rtU", "rUt", "Urt", "trU", "tUr", "Utr"] OpenTextMode: TypeAlias = OpenTextModeUpdating | OpenTextModeWriting | OpenTextModeReading OpenBinaryModeUpdating: TypeAlias = Literal[ "rb+", "r+b", "+rb", "br+", "b+r", "+br", "wb+", "w+b", "+wb", "bw+", "b+w", "+bw", "ab+", "a+b", "+ab", "ba+", "b+a", "+ba", "xb+", "x+b", "+xb", "bx+", "b+x", "+bx", ] OpenBinaryModeWriting: TypeAlias = Literal["wb", "bw", "ab", "ba", "xb", "bx"] OpenBinaryModeReading: TypeAlias = Literal["rb", "br", "rbU", "rUb", "Urb", "brU", "bUr", "Ubr"] OpenBinaryMode: TypeAlias = OpenBinaryModeUpdating | OpenBinaryModeReading | OpenBinaryModeWriting # stable class HasFileno(Protocol): def fileno(self) -> int: ... FileDescriptor: TypeAlias = int # stable FileDescriptorLike: TypeAlias = int | HasFileno # stable FileDescriptorOrPath: TypeAlias = int | StrOrBytesPath # stable class SupportsRead(Protocol[_T_co]): def read(self, length: int = ..., /) -> _T_co: ... # stable class SupportsReadline(Protocol[_T_co]): def readline(self, length: int = ..., /) -> _T_co: ... # stable class SupportsNoArgReadline(Protocol[_T_co]): def readline(self) -> _T_co: ... # stable class SupportsWrite(Protocol[_T_contra]): def write(self, s: _T_contra, /) -> object: ... # stable class SupportsFlush(Protocol): def flush(self) -> object: ... # Suitable for dictionary view objects class Viewable(Protocol[_T_co]): def __len__(self) -> int: ... def __iter__(self) -> Iterator[_T_co]: ... class SupportsGetItemViewable(Protocol[_KT, _VT_co]): def __len__(self) -> int: ... def __iter__(self) -> Iterator[_KT]: ... def __getitem__(self, key: _KT, /) -> _VT_co: ... # Unfortunately PEP 688 does not allow us to distinguish read-only # from writable buffers. We use these aliases for readability for now. # Perhaps a future extension of the buffer protocol will allow us to # distinguish these cases in the type system. ReadOnlyBuffer: TypeAlias = Buffer # stable # Anything that implements the read-write buffer interface. WriteableBuffer: TypeAlias = Buffer # Same as WriteableBuffer, but also includes read-only buffer types (like bytes). ReadableBuffer: TypeAlias = Buffer # stable class SliceableBuffer(Buffer, Protocol): def __getitem__(self, slice: slice[SupportsIndex | None], /) -> Sequence[int]: ... class IndexableBuffer(Buffer, Protocol): def __getitem__(self, i: int, /) -> int: ... class SupportsGetItemBuffer(SliceableBuffer, IndexableBuffer, Protocol): def __contains__(self, x: Any, /) -> bool: ... @overload def __getitem__(self, slice: slice[SupportsIndex | None], /) -> Sequence[int]: ... @overload def __getitem__(self, i: int, /) -> int: ... class SizedBuffer(Sized, Buffer, Protocol): ... ExcInfo: TypeAlias = tuple[type[BaseException], BaseException, TracebackType] OptExcInfo: TypeAlias = ExcInfo | tuple[None, None, None] # stable if sys.version_info >= (3, 10): from types import NoneType as NoneType else: # Used by type checkers for checks involving None (does not exist at runtime) @final class NoneType: def __bool__(self) -> Literal[False]: ... # This is an internal CPython type that is like, but subtly different from, a NamedTuple # Subclasses of this type are found in multiple modules. # In typeshed, `structseq` is only ever used as a mixin in combination with a fixed-length `Tuple` # See discussion at #6546 & #6560 # `structseq` classes are unsubclassable, so are all decorated with `@final`. class structseq(Generic[_T_co]): n_fields: Final[int] n_unnamed_fields: Final[int] n_sequence_fields: Final[int] # The first parameter will generally only take an iterable of a specific length. # E.g. `os.uname_result` takes any iterable of length exactly 5. # # The second parameter will accept a dict of any kind without raising an exception, # but only has any meaning if you supply it a dict where the keys are strings. # https://github.com/python/typeshed/pull/6560#discussion_r767149830 def __new__(cls, sequence: Iterable[_T_co], dict: dict[str, Any] = ...) -> _Self: ... if sys.version_info >= (3, 13): def __replace__(self, **kwargs: Any) -> _Self: ... # Superset of typing.AnyStr that also includes LiteralString AnyOrLiteralStr = TypeVar("AnyOrLiteralStr", str, bytes, LiteralString) # noqa: Y001 # Represents when str or LiteralStr is acceptable. Useful for string processing # APIs where literalness of return value depends on literalness of inputs StrOrLiteralStr = TypeVar("StrOrLiteralStr", LiteralString, str) # noqa: Y001 # Objects suitable to be passed to sys.setprofile, threading.setprofile, and similar ProfileFunction: TypeAlias = Callable[[FrameType, str, Any], object] # Objects suitable to be passed to sys.settrace, threading.settrace, and similar TraceFunction: TypeAlias = Callable[[FrameType, str, Any], TraceFunction | None] # experimental # Might not work as expected for pyright, see # https://github.com/python/typeshed/pull/9362 # https://github.com/microsoft/pyright/issues/4339 class DataclassInstance(Protocol): __dataclass_fields__: ClassVar[dict[str, Field[Any]]] # Anything that can be passed to the int/float constructors if sys.version_info >= (3, 14): ConvertibleToInt: TypeAlias = str | ReadableBuffer | SupportsInt | SupportsIndex else: ConvertibleToInt: TypeAlias = str | ReadableBuffer | SupportsInt | SupportsIndex | SupportsTrunc ConvertibleToFloat: TypeAlias = str | ReadableBuffer | SupportsFloat | SupportsIndex # A few classes updated from Foo(str, Enum) to Foo(StrEnum). This is a convenience so these # can be accurate on all python versions without getting too wordy if sys.version_info >= (3, 11): from enum import StrEnum as StrEnum else: from enum import Enum class StrEnum(str, Enum): ... # Objects that appear in annotations or in type expressions. # Similar to PEP 747's TypeForm but a little broader. AnnotationForm: TypeAlias = Any if sys.version_info >= (3, 14): from annotationlib import Format # These return annotations, which can be arbitrary objects AnnotateFunc: TypeAlias = Callable[[Format], dict[str, AnnotationForm]] EvaluateFunc: TypeAlias = Callable[[Format], AnnotationForm]