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typing_extensions.py
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import abc
import builtins
import collections
import collections.abc
import contextlib
import enum
import functools
import inspect
import io
import keyword
import operator
import sys
import types as _types
import typing
import warnings
# Breakpoint: https://github.com/python/cpython/pull/119891
if sys.version_info >= (3, 14):
import annotationlib
__all__ = [
# Super-special typing primitives.
'Any',
'ClassVar',
'Concatenate',
'Final',
'LiteralString',
'ParamSpec',
'ParamSpecArgs',
'ParamSpecKwargs',
'Self',
'Type',
'TypeVar',
'TypeVarTuple',
'Unpack',
# ABCs (from collections.abc).
'Awaitable',
'AsyncIterator',
'AsyncIterable',
'Coroutine',
'AsyncGenerator',
'AsyncContextManager',
'Buffer',
'ChainMap',
# Concrete collection types.
'ContextManager',
'Counter',
'Deque',
'DefaultDict',
'NamedTuple',
'OrderedDict',
'TypedDict',
# Structural checks, a.k.a. protocols.
'SupportsAbs',
'SupportsBytes',
'SupportsComplex',
'SupportsFloat',
'SupportsIndex',
'SupportsInt',
'SupportsRound',
'Reader',
'Writer',
# One-off things.
'Annotated',
'assert_never',
'assert_type',
'clear_overloads',
'dataclass_transform',
'deprecated',
'disjoint_base',
'Doc',
'evaluate_forward_ref',
'get_overloads',
'final',
'Format',
'get_annotations',
'get_args',
'get_origin',
'get_original_bases',
'get_protocol_members',
'get_type_hints',
'IntVar',
'is_protocol',
'is_typeddict',
'Literal',
'NewType',
'overload',
'override',
'Protocol',
'Sentinel',
'reveal_type',
'runtime',
'runtime_checkable',
'Text',
'TypeAlias',
'TypeAliasType',
'TypeForm',
'TypeGuard',
'TypeIs',
'TYPE_CHECKING',
'type_repr',
'Never',
'NoReturn',
'ReadOnly',
'Required',
'NotRequired',
'NoDefault',
'NoExtraItems',
# Pure aliases, have always been in typing
'AbstractSet',
'AnyStr',
'BinaryIO',
'Callable',
'Collection',
'Container',
'Dict',
'ForwardRef',
'FrozenSet',
'Generator',
'Generic',
'Hashable',
'IO',
'ItemsView',
'Iterable',
'Iterator',
'KeysView',
'List',
'Mapping',
'MappingView',
'Match',
'MutableMapping',
'MutableSequence',
'MutableSet',
'Optional',
'Pattern',
'Reversible',
'Sequence',
'Set',
'Sized',
'TextIO',
'Tuple',
'Union',
'ValuesView',
'cast',
'no_type_check',
]
# for backward compatibility
PEP_560 = True
GenericMeta = type
# Breakpoint: https://github.com/python/cpython/pull/116129
_PEP_696_IMPLEMENTED = sys.version_info >= (3, 13, 0, "beta")
# Added with bpo-45166 to 3.10.1+ and some 3.9 versions
_FORWARD_REF_HAS_CLASS = "__forward_is_class__" in typing.ForwardRef.__slots__
class Sentinel:
"""Create a unique sentinel object.
*name* should be the name of the variable to which the return value shall be assigned.
*repr*, if supplied, will be used for the repr of the sentinel object.
If not provided, "<name>" will be used.
"""
def __init__(
self,
name: str,
repr: typing.Optional[str] = None,
):
self._name = name
self._repr = repr if repr is not None else f'<{name}>'
def __repr__(self):
return self._repr
if sys.version_info < (3, 11):
# The presence of this method convinces typing._type_check
# that Sentinels are types.
def __call__(self, *args, **kwargs):
raise TypeError(f"{type(self).__name__!r} object is not callable")
# Breakpoint: https://github.com/python/cpython/pull/21515
if sys.version_info >= (3, 10):
def __or__(self, other):
return typing.Union[self, other]
def __ror__(self, other):
return typing.Union[other, self]
def __getstate__(self):
raise TypeError(f"Cannot pickle {type(self).__name__!r} object")
_marker = Sentinel("sentinel")
# The functions below are modified copies of typing internal helpers.
# They are needed by _ProtocolMeta and they provide support for PEP 646.
# Breakpoint: https://github.com/python/cpython/pull/27342
if sys.version_info >= (3, 10):
def _should_collect_from_parameters(t):
return isinstance(
t, (typing._GenericAlias, _types.GenericAlias, _types.UnionType)
)
else:
def _should_collect_from_parameters(t):
return isinstance(t, (typing._GenericAlias, _types.GenericAlias))
NoReturn = typing.NoReturn
# Some unconstrained type variables. These are used by the container types.
# (These are not for export.)
T = typing.TypeVar('T') # Any type.
KT = typing.TypeVar('KT') # Key type.
VT = typing.TypeVar('VT') # Value type.
T_co = typing.TypeVar('T_co', covariant=True) # Any type covariant containers.
T_contra = typing.TypeVar('T_contra', contravariant=True) # Ditto contravariant.
# Breakpoint: https://github.com/python/cpython/pull/31841
if sys.version_info >= (3, 11):
from typing import Any
else:
class _AnyMeta(type):
def __instancecheck__(self, obj):
if self is Any:
raise TypeError("typing_extensions.Any cannot be used with isinstance()")
return super().__instancecheck__(obj)
def __repr__(self):
if self is Any:
return "typing_extensions.Any"
return super().__repr__()
class Any(metaclass=_AnyMeta):
"""Special type indicating an unconstrained type.
- Any is compatible with every type.
- Any assumed to have all methods.
- All values assumed to be instances of Any.
Note that all the above statements are true from the point of view of
static type checkers. At runtime, Any should not be used with instance
checks.
"""
def __new__(cls, *args, **kwargs):
if cls is Any:
raise TypeError("Any cannot be instantiated")
return super().__new__(cls, *args, **kwargs)
ClassVar = typing.ClassVar
# Vendored from cpython typing._SpecialFrom
# Having a separate class means that instances will not be rejected by
# typing._type_check.
class _SpecialForm(typing._Final, _root=True):
__slots__ = ('_name', '__doc__', '_getitem')
def __init__(self, getitem):
self._getitem = getitem
self._name = getitem.__name__
self.__doc__ = getitem.__doc__
def __getattr__(self, item):
if item in {'__name__', '__qualname__'}:
return self._name
raise AttributeError(item)
def __mro_entries__(self, bases):
raise TypeError(f"Cannot subclass {self!r}")
def __repr__(self):
return f'typing_extensions.{self._name}'
def __reduce__(self):
return self._name
def __call__(self, *args, **kwds):
raise TypeError(f"Cannot instantiate {self!r}")
def __or__(self, other):
return typing.Union[self, other]
def __ror__(self, other):
return typing.Union[other, self]
def __instancecheck__(self, obj):
raise TypeError(f"{self} cannot be used with isinstance()")
def __subclasscheck__(self, cls):
raise TypeError(f"{self} cannot be used with issubclass()")
@typing._tp_cache
def __getitem__(self, parameters):
return self._getitem(self, parameters)
# Note that inheriting from this class means that the object will be
# rejected by typing._type_check, so do not use it if the special form
# is arguably valid as a type by itself.
class _ExtensionsSpecialForm(typing._SpecialForm, _root=True):
def __repr__(self):
return 'typing_extensions.' + self._name
Final = typing.Final
# Breakpoint: https://github.com/python/cpython/pull/30530
if sys.version_info >= (3, 11):
final = typing.final
else:
# @final exists in 3.8+, but we backport it for all versions
# before 3.11 to keep support for the __final__ attribute.
# See https://bugs.python.org/issue46342
def final(f):
"""This decorator can be used to indicate to type checkers that
the decorated method cannot be overridden, and decorated class
cannot be subclassed. For example:
class Base:
@final
def done(self) -> None:
...
class Sub(Base):
def done(self) -> None: # Error reported by type checker
...
@final
class Leaf:
...
class Other(Leaf): # Error reported by type checker
...
There is no runtime checking of these properties. The decorator
sets the ``__final__`` attribute to ``True`` on the decorated object
to allow runtime introspection.
"""
try:
f.__final__ = True
except (AttributeError, TypeError):
# Skip the attribute silently if it is not writable.
# AttributeError happens if the object has __slots__ or a
# read-only property, TypeError if it's a builtin class.
pass
return f
if hasattr(typing, "disjoint_base"): # 3.15
disjoint_base = typing.disjoint_base
else:
def disjoint_base(cls):
"""This decorator marks a class as a disjoint base.
Child classes of a disjoint base cannot inherit from other disjoint bases that are
not parent classes of the disjoint base.
For example:
@disjoint_base
class Disjoint1: pass
@disjoint_base
class Disjoint2: pass
class Disjoint3(Disjoint1, Disjoint2): pass # Type checker error
Type checkers can use knowledge of disjoint bases to detect unreachable code
and determine when two types can overlap.
See PEP 800."""
cls.__disjoint_base__ = True
return cls
def IntVar(name):
return typing.TypeVar(name)
# A Literal bug was fixed in 3.11.0, 3.10.1 and 3.9.8
# Breakpoint: https://github.com/python/cpython/pull/29334
if sys.version_info >= (3, 10, 1):
Literal = typing.Literal
else:
def _flatten_literal_params(parameters):
"""An internal helper for Literal creation: flatten Literals among parameters"""
params = []
for p in parameters:
if isinstance(p, _LiteralGenericAlias):
params.extend(p.__args__)
else:
params.append(p)
return tuple(params)
def _value_and_type_iter(params):
for p in params:
yield p, type(p)
class _LiteralGenericAlias(typing._GenericAlias, _root=True):
def __eq__(self, other):
if not isinstance(other, _LiteralGenericAlias):
return NotImplemented
these_args_deduped = set(_value_and_type_iter(self.__args__))
other_args_deduped = set(_value_and_type_iter(other.__args__))
return these_args_deduped == other_args_deduped
def __hash__(self):
return hash(frozenset(_value_and_type_iter(self.__args__)))
class _LiteralForm(_ExtensionsSpecialForm, _root=True):
def __init__(self, doc: str):
self._name = 'Literal'
self._doc = self.__doc__ = doc
def __getitem__(self, parameters):
if not isinstance(parameters, tuple):
parameters = (parameters,)
parameters = _flatten_literal_params(parameters)
val_type_pairs = list(_value_and_type_iter(parameters))
try:
deduped_pairs = set(val_type_pairs)
except TypeError:
# unhashable parameters
pass
else:
# similar logic to typing._deduplicate on Python 3.9+
if len(deduped_pairs) < len(val_type_pairs):
new_parameters = []
for pair in val_type_pairs:
if pair in deduped_pairs:
new_parameters.append(pair[0])
deduped_pairs.remove(pair)
assert not deduped_pairs, deduped_pairs
parameters = tuple(new_parameters)
return _LiteralGenericAlias(self, parameters)
Literal = _LiteralForm(doc="""\
A type that can be used to indicate to type checkers
that the corresponding value has a value literally equivalent
to the provided parameter. For example:
var: Literal[4] = 4
The type checker understands that 'var' is literally equal to
the value 4 and no other value.
Literal[...] cannot be subclassed. There is no runtime
checking verifying that the parameter is actually a value
instead of a type.""")
_overload_dummy = typing._overload_dummy
if hasattr(typing, "get_overloads"): # 3.11+
overload = typing.overload
get_overloads = typing.get_overloads
clear_overloads = typing.clear_overloads
else:
# {module: {qualname: {firstlineno: func}}}
_overload_registry = collections.defaultdict(
functools.partial(collections.defaultdict, dict)
)
def overload(func):
"""Decorator for overloaded functions/methods.
In a stub file, place two or more stub definitions for the same
function in a row, each decorated with @overload. For example:
@overload
def utf8(value: None) -> None: ...
@overload
def utf8(value: bytes) -> bytes: ...
@overload
def utf8(value: str) -> bytes: ...
In a non-stub file (i.e. a regular .py file), do the same but
follow it with an implementation. The implementation should *not*
be decorated with @overload. For example:
@overload
def utf8(value: None) -> None: ...
@overload
def utf8(value: bytes) -> bytes: ...
@overload
def utf8(value: str) -> bytes: ...
def utf8(value):
# implementation goes here
The overloads for a function can be retrieved at runtime using the
get_overloads() function.
"""
# classmethod and staticmethod
f = getattr(func, "__func__", func)
try:
_overload_registry[f.__module__][f.__qualname__][
f.__code__.co_firstlineno
] = func
except AttributeError:
# Not a normal function; ignore.
pass
return _overload_dummy
def get_overloads(func):
"""Return all defined overloads for *func* as a sequence."""
# classmethod and staticmethod
f = getattr(func, "__func__", func)
if f.__module__ not in _overload_registry:
return []
mod_dict = _overload_registry[f.__module__]
if f.__qualname__ not in mod_dict:
return []
return list(mod_dict[f.__qualname__].values())
def clear_overloads():
"""Clear all overloads in the registry."""
_overload_registry.clear()
# This is not a real generic class. Don't use outside annotations.
Type = typing.Type
# Various ABCs mimicking those in collections.abc.
# A few are simply re-exported for completeness.
Awaitable = typing.Awaitable
Coroutine = typing.Coroutine
AsyncIterable = typing.AsyncIterable
AsyncIterator = typing.AsyncIterator
Deque = typing.Deque
DefaultDict = typing.DefaultDict
OrderedDict = typing.OrderedDict
Counter = typing.Counter
ChainMap = typing.ChainMap
Text = typing.Text
TYPE_CHECKING = typing.TYPE_CHECKING
# Breakpoint: https://github.com/python/cpython/pull/118681
if sys.version_info >= (3, 13, 0, "beta"):
from typing import AsyncContextManager, AsyncGenerator, ContextManager, Generator
else:
def _is_dunder(attr):
return attr.startswith('__') and attr.endswith('__')
class _SpecialGenericAlias(typing._SpecialGenericAlias, _root=True):
def __init__(self, origin, nparams, *, defaults, inst=True, name=None):
assert nparams > 0, "`nparams` must be a positive integer"
assert defaults, "Must always specify a non-empty sequence for `defaults`"
super().__init__(origin, nparams, inst=inst, name=name)
self._defaults = defaults
def __setattr__(self, attr, val):
allowed_attrs = {'_name', '_inst', '_nparams', '_defaults'}
if _is_dunder(attr) or attr in allowed_attrs:
object.__setattr__(self, attr, val)
else:
setattr(self.__origin__, attr, val)
@typing._tp_cache
def __getitem__(self, params):
if not isinstance(params, tuple):
params = (params,)
msg = "Parameters to generic types must be types."
params = tuple(typing._type_check(p, msg) for p in params)
if (
len(params) < self._nparams
and len(params) + len(self._defaults) >= self._nparams
):
params = (*params, *self._defaults[len(params) - self._nparams:])
actual_len = len(params)
if actual_len != self._nparams:
expected = f"at least {self._nparams - len(self._defaults)}"
raise TypeError(
f"Too {'many' if actual_len > self._nparams else 'few'}"
f" arguments for {self};"
f" actual {actual_len}, expected {expected}"
)
return self.copy_with(params)
_NoneType = type(None)
Generator = _SpecialGenericAlias(
collections.abc.Generator, 3, defaults=(_NoneType, _NoneType)
)
AsyncGenerator = _SpecialGenericAlias(
collections.abc.AsyncGenerator, 2, defaults=(_NoneType,)
)
ContextManager = _SpecialGenericAlias(
contextlib.AbstractContextManager,
2,
name="ContextManager",
defaults=(typing.Optional[bool],)
)
AsyncContextManager = _SpecialGenericAlias(
contextlib.AbstractAsyncContextManager,
2,
name="AsyncContextManager",
defaults=(typing.Optional[bool],)
)
_PROTO_ALLOWLIST = {
'collections.abc': [
'Callable', 'Awaitable', 'Iterable', 'Iterator', 'AsyncIterable',
'Hashable', 'Sized', 'Container', 'Collection', 'Reversible', 'Buffer',
],
'contextlib': ['AbstractContextManager', 'AbstractAsyncContextManager'],
'typing_extensions': ['Buffer'],
}
_EXCLUDED_ATTRS = frozenset(typing.EXCLUDED_ATTRIBUTES) | {
"__match_args__", "__protocol_attrs__", "__non_callable_proto_members__",
"__final__",
}
def _get_protocol_attrs(cls):
attrs = set()
for base in cls.__mro__[:-1]: # without object
if base.__name__ in {'Protocol', 'Generic'}:
continue
annotations = getattr(base, '__annotations__', {})
for attr in (*base.__dict__, *annotations):
if (not attr.startswith('_abc_') and attr not in _EXCLUDED_ATTRS):
attrs.add(attr)
return attrs
def _caller(depth=1, default='__main__'):
try:
return sys._getframemodulename(depth + 1) or default
except AttributeError: # For platforms without _getframemodulename()
pass
try:
return sys._getframe(depth + 1).f_globals.get('__name__', default)
except (AttributeError, ValueError): # For platforms without _getframe()
pass
return None
# `__match_args__` attribute was removed from protocol members in 3.13,
# we want to backport this change to older Python versions.
# Breakpoint: https://github.com/python/cpython/pull/110683
if sys.version_info >= (3, 13):
Protocol = typing.Protocol
else:
def _allow_reckless_class_checks(depth=2):
"""Allow instance and class checks for special stdlib modules.
The abc and functools modules indiscriminately call isinstance() and
issubclass() on the whole MRO of a user class, which may contain protocols.
"""
return _caller(depth) in {'abc', 'functools', None}
def _no_init(self, *args, **kwargs):
if type(self)._is_protocol:
raise TypeError('Protocols cannot be instantiated')
def _type_check_issubclass_arg_1(arg):
"""Raise TypeError if `arg` is not an instance of `type`
in `issubclass(arg, <protocol>)`.
In most cases, this is verified by type.__subclasscheck__.
Checking it again unnecessarily would slow down issubclass() checks,
so, we don't perform this check unless we absolutely have to.
For various error paths, however,
we want to ensure that *this* error message is shown to the user
where relevant, rather than a typing.py-specific error message.
"""
if not isinstance(arg, type):
# Same error message as for issubclass(1, int).
raise TypeError('issubclass() arg 1 must be a class')
# Inheriting from typing._ProtocolMeta isn't actually desirable,
# but is necessary to allow typing.Protocol and typing_extensions.Protocol
# to mix without getting TypeErrors about "metaclass conflict"
class _ProtocolMeta(type(typing.Protocol)):
# This metaclass is somewhat unfortunate,
# but is necessary for several reasons...
#
# NOTE: DO NOT call super() in any methods in this class
# That would call the methods on typing._ProtocolMeta on Python <=3.11
# and those are slow
def __new__(mcls, name, bases, namespace, **kwargs):
if name == "Protocol" and len(bases) < 2:
pass
elif {Protocol, typing.Protocol} & set(bases):
for base in bases:
if not (
base in {object, typing.Generic, Protocol, typing.Protocol}
or base.__name__ in _PROTO_ALLOWLIST.get(base.__module__, [])
or is_protocol(base)
):
raise TypeError(
f"Protocols can only inherit from other protocols, "
f"got {base!r}"
)
return abc.ABCMeta.__new__(mcls, name, bases, namespace, **kwargs)
def __init__(cls, *args, **kwargs):
abc.ABCMeta.__init__(cls, *args, **kwargs)
if getattr(cls, "_is_protocol", False):
cls.__protocol_attrs__ = _get_protocol_attrs(cls)
def __subclasscheck__(cls, other):
if cls is Protocol:
return type.__subclasscheck__(cls, other)
if (
getattr(cls, '_is_protocol', False)
and not _allow_reckless_class_checks()
):
if not getattr(cls, '_is_runtime_protocol', False):
_type_check_issubclass_arg_1(other)
raise TypeError(
"Instance and class checks can only be used with "
"@runtime_checkable protocols"
)
if (
# this attribute is set by @runtime_checkable:
cls.__non_callable_proto_members__
and cls.__dict__.get("__subclasshook__") is _proto_hook
):
_type_check_issubclass_arg_1(other)
non_method_attrs = sorted(cls.__non_callable_proto_members__)
raise TypeError(
"Protocols with non-method members don't support issubclass()."
f" Non-method members: {str(non_method_attrs)[1:-1]}."
)
return abc.ABCMeta.__subclasscheck__(cls, other)
def __instancecheck__(cls, instance):
# We need this method for situations where attributes are
# assigned in __init__.
if cls is Protocol:
return type.__instancecheck__(cls, instance)
if not getattr(cls, "_is_protocol", False):
# i.e., it's a concrete subclass of a protocol
return abc.ABCMeta.__instancecheck__(cls, instance)
if (
not getattr(cls, '_is_runtime_protocol', False) and
not _allow_reckless_class_checks()
):
raise TypeError("Instance and class checks can only be used with"
" @runtime_checkable protocols")
if abc.ABCMeta.__instancecheck__(cls, instance):
return True
for attr in cls.__protocol_attrs__:
try:
val = inspect.getattr_static(instance, attr)
except AttributeError:
break
# this attribute is set by @runtime_checkable:
if val is None and attr not in cls.__non_callable_proto_members__:
break
else:
return True
return False
def __eq__(cls, other):
# Hack so that typing.Generic.__class_getitem__
# treats typing_extensions.Protocol
# as equivalent to typing.Protocol
if abc.ABCMeta.__eq__(cls, other) is True:
return True
return cls is Protocol and other is typing.Protocol
# This has to be defined, or the abc-module cache
# complains about classes with this metaclass being unhashable,
# if we define only __eq__!
def __hash__(cls) -> int:
return type.__hash__(cls)
@classmethod
def _proto_hook(cls, other):
if not cls.__dict__.get('_is_protocol', False):
return NotImplemented
for attr in cls.__protocol_attrs__:
for base in other.__mro__:
# Check if the members appears in the class dictionary...
if attr in base.__dict__:
if base.__dict__[attr] is None:
return NotImplemented
break
# ...or in annotations, if it is a sub-protocol.
annotations = getattr(base, '__annotations__', {})
if (
isinstance(annotations, collections.abc.Mapping)
and attr in annotations
and is_protocol(other)
):
break
else:
return NotImplemented
return True
class Protocol(typing.Generic, metaclass=_ProtocolMeta):
__doc__ = typing.Protocol.__doc__
__slots__ = ()
_is_protocol = True
_is_runtime_protocol = False
def __init_subclass__(cls, *args, **kwargs):
super().__init_subclass__(*args, **kwargs)
# Determine if this is a protocol or a concrete subclass.
if not cls.__dict__.get('_is_protocol', False):
cls._is_protocol = any(b is Protocol for b in cls.__bases__)
# Set (or override) the protocol subclass hook.
if '__subclasshook__' not in cls.__dict__:
cls.__subclasshook__ = _proto_hook
# Prohibit instantiation for protocol classes
if cls._is_protocol and cls.__init__ is Protocol.__init__:
cls.__init__ = _no_init
# Breakpoint: https://github.com/python/cpython/pull/113401
if sys.version_info >= (3, 13):
runtime_checkable = typing.runtime_checkable
else:
def runtime_checkable(cls):
"""Mark a protocol class as a runtime protocol.
Such protocol can be used with isinstance() and issubclass().
Raise TypeError if applied to a non-protocol class.
This allows a simple-minded structural check very similar to
one trick ponies in collections.abc such as Iterable.
For example::
@runtime_checkable
class Closable(Protocol):
def close(self): ...
assert isinstance(open('/some/file'), Closable)
Warning: this will check only the presence of the required methods,
not their type signatures!
"""
if not issubclass(cls, typing.Generic) or not getattr(cls, '_is_protocol', False):
raise TypeError(f'@runtime_checkable can be only applied to protocol classes,'
f' got {cls!r}')
cls._is_runtime_protocol = True
# typing.Protocol classes on <=3.11 break if we execute this block,
# because typing.Protocol classes on <=3.11 don't have a
# `__protocol_attrs__` attribute, and this block relies on the
# `__protocol_attrs__` attribute. Meanwhile, typing.Protocol classes on 3.12.2+
# break if we *don't* execute this block, because *they* assume that all
# protocol classes have a `__non_callable_proto_members__` attribute
# (which this block sets)
if isinstance(cls, _ProtocolMeta) or sys.version_info >= (3, 12, 2):
# PEP 544 prohibits using issubclass()
# with protocols that have non-method members.
# See gh-113320 for why we compute this attribute here,
# rather than in `_ProtocolMeta.__init__`
cls.__non_callable_proto_members__ = set()
for attr in cls.__protocol_attrs__:
try:
is_callable = callable(getattr(cls, attr, None))
except Exception as e:
raise TypeError(
f"Failed to determine whether protocol member {attr!r} "
"is a method member"
) from e
else:
if not is_callable:
cls.__non_callable_proto_members__.add(attr)
return cls
# The "runtime" alias exists for backwards compatibility.
runtime = runtime_checkable
# Our version of runtime-checkable protocols is faster on Python <=3.11
# Breakpoint: https://github.com/python/cpython/pull/112717
if sys.version_info >= (3, 12):
SupportsInt = typing.SupportsInt
SupportsFloat = typing.SupportsFloat
SupportsComplex = typing.SupportsComplex
SupportsBytes = typing.SupportsBytes
SupportsIndex = typing.SupportsIndex
SupportsAbs = typing.SupportsAbs
SupportsRound = typing.SupportsRound
else:
@runtime_checkable
class SupportsInt(Protocol):
"""An ABC with one abstract method __int__."""
__slots__ = ()
@abc.abstractmethod
def __int__(self) -> int:
pass
@runtime_checkable
class SupportsFloat(Protocol):
"""An ABC with one abstract method __float__."""
__slots__ = ()
@abc.abstractmethod
def __float__(self) -> float:
pass
@runtime_checkable
class SupportsComplex(Protocol):
"""An ABC with one abstract method __complex__."""
__slots__ = ()
@abc.abstractmethod
def __complex__(self) -> complex:
pass
@runtime_checkable
class SupportsBytes(Protocol):
"""An ABC with one abstract method __bytes__."""
__slots__ = ()
@abc.abstractmethod
def __bytes__(self) -> bytes:
pass
@runtime_checkable
class SupportsIndex(Protocol):
__slots__ = ()
@abc.abstractmethod
def __index__(self) -> int:
pass
@runtime_checkable
class SupportsAbs(Protocol[T_co]):
"""
An ABC with one abstract method __abs__ that is covariant in its return type.
"""
__slots__ = ()
@abc.abstractmethod
def __abs__(self) -> T_co:
pass
@runtime_checkable
class SupportsRound(Protocol[T_co]):
"""
An ABC with one abstract method __round__ that is covariant in its return type.
"""
__slots__ = ()
@abc.abstractmethod
def __round__(self, ndigits: int = 0) -> T_co:
pass
if hasattr(io, "Reader") and hasattr(io, "Writer"):
Reader = io.Reader
Writer = io.Writer
else:
@runtime_checkable
class Reader(Protocol[T_co]):
"""Protocol for simple I/O reader instances.
This protocol only supports blocking I/O.
"""
__slots__ = ()
@abc.abstractmethod
def read(self, size: int = ..., /) -> T_co:
"""Read data from the input stream and return it.
If *size* is specified, at most *size* items (bytes/characters) will be
read.
"""
@runtime_checkable
class Writer(Protocol[T_contra]):
"""Protocol for simple I/O writer instances.
This protocol only supports blocking I/O.
"""