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typing

The typing module: Support for gradual typing as defined by PEP 484 and subsequent PEPs.

Among other things, the module includes the following:
* Generic, Protocol, and internal machinery to support generic aliases.
  All subscripted types like X[int], Union[int, str] are generic aliases.
* Various "special forms" that have unique meanings in type annotations:
  Any, Never, ClassVar, Self, Concatenate, Unpack, and others.
* Classes whose instances can be type arguments to generic classes and functions:
  TypeVar, ParamSpec, TypeVarTuple.
* Public helper functions: get_type_hints, overload, cast, final, and others.
* Several protocols to support duck-typing:
  SupportsFloat, SupportsIndex, SupportsAbs, and others.
* Special types: NewType, NamedTuple, TypedDict.
* Deprecated aliases for builtin types and collections.abc ABCs.

Any name not present in __all__ is an implementation detail
that may be changed without notice. Use at your own risk!

Symbols in typing

a

AbstractSet: Deprecated alias to collections.abc.Set.
Annotated: Add context-specific metadata to a type.
Any: Special type indicating an unconstrained type.
AnyStr: A constrained type variable.
assert_never: Statically assert that a line of code is unreachable.
assert_type: Ask a static type checker to confirm that the value is of the given type.
AsyncContextManager: Deprecated alias to contextlib.AbstractAsyncContextManager.
AsyncGenerator: Deprecated alias to collections.abc.AsyncGenerator.
AsyncIterable: Deprecated alias to collections.abc.AsyncIterable.
AsyncIterator: Deprecated alias to collections.abc.AsyncIterator.
Awaitable: Deprecated alias to collections.abc.Awaitable.

b

BinaryIO: Typed approximation of the return of open() in binary mode.
ByteString: Deprecated alias to collections.abc.ByteString.

c

Callable: Deprecated alias to collections.abc.Callable.
cast: Cast a value to a type.
ChainMap: Deprecated alias to collections.ChainMap.
ClassVar: Special type construct to mark class variables.
clear_overloads: Clear all overloads in the registry.
Collection: Deprecated alias to collections.abc.Collection.
Concatenate: Special form for annotating higher-order functions.
Container: Deprecated alias to collections.abc.Container.
ContextManager: Deprecated alias to contextlib.AbstractContextManager.
Coroutine: Deprecated alias to collections.abc.Coroutine.
Counter: Deprecated alias to collections.Counter.

d

dataclass_transform: Decorator to mark an object as providing dataclass-like behavior.
DefaultDict: Deprecated alias to collections.defaultdict.
Deque: Deprecated alias to collections.deque.
Dict: Deprecated alias to dict.
disjoint_base: This decorator marks a class as a disjoint base.

e

evaluate_forward_ref: Evaluate a forward reference as a type hint.

f

final: Decorator to indicate final methods and final classes.
Final: Special typing construct to indicate final names to type checkers.
ForwardRef: Wrapper that holds a forward reference.
FrozenSet: Deprecated alias to frozenset.

g

Generator: Deprecated alias to collections.abc.Generator.
Generic: Abstract base class for generic types.
get_args: Get type arguments with all substitutions performed.
get_origin: Get the unsubscripted version of a type.
get_overloads: Return all defined overloads for *func* as a sequence.
get_protocol_members: Return the set of members defined in a Protocol.
get_type_hints: Return type hints for an object.

h

Hashable: Deprecated alias to collections.abc.Hashable.

i

IO: Generic base class for TextIO and BinaryIO.
is_protocol: Return True if the given type is a Protocol.
is_typeddict: Check if an object is a TypedDict class.
ItemsView: Deprecated alias to collections.abc.ItemsView.
Iterable: Deprecated alias to collections.abc.Iterable.
Iterator: Deprecated alias to collections.abc.Iterator.

k

KeysView: Deprecated alias to collections.abc.KeysView.

l

List: Deprecated alias to list.
Literal: Special typing form to define literal types (a.k.a.
LiteralString: Represents an arbitrary literal string.

m

Mapping: Deprecated alias to collections.abc.Mapping.
MappingView: Deprecated alias to collections.abc.MappingView.
Match: Deprecated alias to re.Match.
MutableMapping: Deprecated alias to collections.abc.MutableMapping.
MutableSequence: Deprecated alias to collections.abc.MutableSequence.
MutableSet: Deprecated alias to collections.abc.MutableSet.

n

NamedTuple: Typed version of collections.namedtuple.
Never: The bottom type, a type that has no members.
NewType: NewType creates simple unique types with almost zero runtime overhead.
no_type_check: Decorator to indicate that annotations are not type hints.
NoDefault: A sentinel object used to indicate that a type parameter has no default value.
NoExtraItems: A sentinel object used to indicate that a TypedDict does not have the extra_items class argument.
NoReturn: Special type indicating functions that never return.
NotRequired: Special typing construct to mark a TypedDict key as potentially missing.

o

Optional: Optional[X] is equivalent to X | None.
OrderedDict: Deprecated alias to collections.OrderedDict.
overload: Decorator for overloaded functions/methods.
override: Indicate that a method is intended to override a method in a base class.

p

ParamSpec: Parameter specification variable.
ParamSpecArgs: The args for a ParamSpec object.
ParamSpecKwargs: The kwargs for a ParamSpec object.
Pattern: Deprecated alias to re.Pattern.
Protocol: Base class for protocol classes.

r

ReadOnly: A special typing construct to mark an item of a TypedDict as read-only.
Required: Special typing construct to mark a TypedDict key as required.
reveal_type: Ask a static type checker to reveal the inferred type of an expression.
Reversible: Deprecated alias to collections.abc.Reversible.
runtime_checkable: Mark a protocol class as a runtime protocol.

s

Self: Used to spell the type of "self" in classes.
Sequence: Deprecated alias to collections.abc.Sequence.
Set: Deprecated alias to set.
Sized: Deprecated alias to collections.abc.Sized.
SupportsAbs: A protocol with one abstract method __abs__ that is covariant in its return type.
SupportsBytes: A protocol with one abstract method __bytes__.
SupportsComplex: A protocol with one abstract method __complex__.
SupportsFloat: A protocol with one abstract method __float__.
SupportsIndex: A protocol with one abstract method __index__.
SupportsInt: A protocol with one abstract method __int__.
SupportsRound: A protocol with one abstract method __round__ that is covariant in its return type.

t

Text: Create a new string object from the given object.
TextIO: Typed approximation of the return of open() in text mode.
Tuple: Deprecated alias to builtins.tuple.
Type: Deprecated alias to builtins.type.
type_check_only: Decorator to mark a class or function as unavailable at runtime.
TYPE_CHECKING: A special constant that is assumed to be True by static type checkers.
TypeAlias: Special form for marking type aliases.
TypeAliasType: Type alias.
TypedDict: A simple typed namespace.
TypeForm: A special form representing the value that results from the evaluation of a type expression.
TypeGuard: Special typing construct for marking user-defined type predicate functions.
TypeIs: Special typing construct for marking user-defined type predicate functions.
TypeVar: Type variable.
TypeVarTuple: Type variable tuple.

u

Union: Represent a union type
Unpack: Type unpack operator.

v

ValuesView: Deprecated alias to collections.abc.ValuesView.

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typing

Symbols in typing

a

b

c

d

e

f

g

h

i

k

l

m

n

o

p

r

s

t

u

v