diff options
Diffstat (limited to 'Lib/typing.py')
| -rw-r--r-- | Lib/typing.py | 102 |
1 files changed, 54 insertions, 48 deletions
diff --git a/Lib/typing.py b/Lib/typing.py index 98af61be8b0..f1455c273d3 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -407,6 +407,17 @@ def _tp_cache(func=None, /, *, typed=False): return decorator +def _rebuild_generic_alias(alias: GenericAlias, args: tuple[object, ...]) -> GenericAlias: + is_unpacked = alias.__unpacked__ + if _should_unflatten_callable_args(alias, args): + t = alias.__origin__[(args[:-1], args[-1])] + else: + t = alias.__origin__[args] + if is_unpacked: + t = Unpack[t] + return t + + def _deprecation_warning_for_no_type_params_passed(funcname: str) -> None: import warnings @@ -426,20 +437,14 @@ class _Sentinel: return '<sentinel>' -_sentinel = _Sentinel() - - -def _eval_type(t, globalns, localns, type_params=_sentinel, *, recursive_guard=frozenset(), - format=None, owner=None): +def _eval_type(t, globalns, localns, type_params, *, recursive_guard=frozenset(), + format=None, owner=None, parent_fwdref=None): """Evaluate all forward references in the given type t. For use of globalns and localns see the docstring for get_type_hints(). recursive_guard is used to prevent infinite recursion with a recursive ForwardRef. """ - if type_params is _sentinel: - _deprecation_warning_for_no_type_params_passed("typing._eval_type") - type_params = () if isinstance(t, _lazy_annotationlib.ForwardRef): # If the forward_ref has __forward_module__ set, evaluate() infers the globals # from the module, and it will probably pick better than the globals we have here. @@ -451,28 +456,23 @@ def _eval_type(t, globalns, localns, type_params=_sentinel, *, recursive_guard=f if isinstance(t, (_GenericAlias, GenericAlias, Union)): if isinstance(t, GenericAlias): args = tuple( - _make_forward_ref(arg) if isinstance(arg, str) else arg + _make_forward_ref(arg, parent_fwdref=parent_fwdref) if isinstance(arg, str) else arg for arg in t.__args__ ) - is_unpacked = t.__unpacked__ - if _should_unflatten_callable_args(t, args): - t = t.__origin__[(args[:-1], args[-1])] - else: - t = t.__origin__[args] - if is_unpacked: - t = Unpack[t] + else: + args = t.__args__ ev_args = tuple( _eval_type( a, globalns, localns, type_params, recursive_guard=recursive_guard, format=format, owner=owner, ) - for a in t.__args__ + for a in args ) if ev_args == t.__args__: return t if isinstance(t, GenericAlias): - return GenericAlias(t.__origin__, ev_args) + return _rebuild_generic_alias(t, ev_args) if isinstance(t, Union): return functools.reduce(operator.or_, ev_args) else: @@ -936,7 +936,12 @@ def TypeIs(self, parameters): return _GenericAlias(self, (item,)) -def _make_forward_ref(code, **kwargs): +def _make_forward_ref(code, *, parent_fwdref=None, **kwargs): + if parent_fwdref is not None: + if parent_fwdref.__forward_module__ is not None: + kwargs['module'] = parent_fwdref.__forward_module__ + if parent_fwdref.__owner__ is not None: + kwargs['owner'] = parent_fwdref.__owner__ forward_ref = _lazy_annotationlib.ForwardRef(code, **kwargs) # For compatibility, eagerly compile the forwardref's code. forward_ref.__forward_code__ @@ -956,12 +961,8 @@ def evaluate_forward_ref( """Evaluate a forward reference as a type hint. This is similar to calling the ForwardRef.evaluate() method, - but unlike that method, evaluate_forward_ref() also: - - * Recursively evaluates forward references nested within the type hint. - * Rejects certain objects that are not valid type hints. - * Replaces type hints that evaluate to None with types.NoneType. - * Supports the *FORWARDREF* and *STRING* formats. + but unlike that method, evaluate_forward_ref() also + recursively evaluates forward references nested within the type hint. *forward_ref* must be an instance of ForwardRef. *owner*, if given, should be the object that holds the annotations that the forward reference @@ -981,29 +982,31 @@ def evaluate_forward_ref( if forward_ref.__forward_arg__ in _recursive_guard: return forward_ref - try: - value = forward_ref.evaluate(globals=globals, locals=locals, - type_params=type_params, owner=owner) - except NameError: - if format == _lazy_annotationlib.Format.FORWARDREF: - return forward_ref - else: - raise - - type_ = _type_check( - value, - "Forward references must evaluate to types.", - is_argument=forward_ref.__forward_is_argument__, - allow_special_forms=forward_ref.__forward_is_class__, - ) + if format is None: + format = _lazy_annotationlib.Format.VALUE + value = forward_ref.evaluate(globals=globals, locals=locals, + type_params=type_params, owner=owner, format=format) + + if (isinstance(value, _lazy_annotationlib.ForwardRef) + and format == _lazy_annotationlib.Format.FORWARDREF): + return value + + if isinstance(value, str): + value = _make_forward_ref(value, module=forward_ref.__forward_module__, + owner=owner or forward_ref.__owner__, + is_argument=forward_ref.__forward_is_argument__, + is_class=forward_ref.__forward_is_class__) + if owner is None: + owner = forward_ref.__owner__ return _eval_type( - type_, + value, globals, locals, type_params, recursive_guard=_recursive_guard | {forward_ref.__forward_arg__}, format=format, owner=owner, + parent_fwdref=forward_ref, ) @@ -1863,7 +1866,9 @@ def _allow_reckless_class_checks(depth=2): 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} + # gh-136047: When `_abc` module is not available, `_py_abc` is required to + # allow `_py_abc.ABCMeta` fallback. + return _caller(depth) in {'abc', '_py_abc', 'functools', None} _PROTO_ALLOWLIST = { @@ -2338,12 +2343,12 @@ def get_type_hints(obj, globalns=None, localns=None, include_extras=False, # This only affects ForwardRefs. base_globals, base_locals = base_locals, base_globals for name, value in ann.items(): - if value is None: - value = type(None) if isinstance(value, str): value = _make_forward_ref(value, is_argument=False, is_class=True) value = _eval_type(value, base_globals, base_locals, base.__type_params__, format=format, owner=obj) + if value is None: + value = type(None) hints[name] = value if include_extras or format == Format.STRING: return hints @@ -2377,8 +2382,6 @@ def get_type_hints(obj, globalns=None, localns=None, include_extras=False, localns = globalns type_params = getattr(obj, "__type_params__", ()) for name, value in hints.items(): - if value is None: - value = type(None) if isinstance(value, str): # class-level forward refs were handled above, this must be either # a module-level annotation or a function argument annotation @@ -2387,7 +2390,10 @@ def get_type_hints(obj, globalns=None, localns=None, include_extras=False, is_argument=not isinstance(obj, types.ModuleType), is_class=False, ) - hints[name] = _eval_type(value, globalns, localns, type_params, format=format, owner=obj) + value = _eval_type(value, globalns, localns, type_params, format=format, owner=obj) + if value is None: + value = type(None) + hints[name] = value return hints if include_extras else {k: _strip_annotations(t) for k, t in hints.items()} @@ -2406,7 +2412,7 @@ def _strip_annotations(t): stripped_args = tuple(_strip_annotations(a) for a in t.__args__) if stripped_args == t.__args__: return t - return GenericAlias(t.__origin__, stripped_args) + return _rebuild_generic_alias(t, stripped_args) if isinstance(t, Union): stripped_args = tuple(_strip_annotations(a) for a in t.__args__) if stripped_args == t.__args__: |