diff options
Diffstat (limited to 'Lib/typing.py')
| -rw-r--r-- | Lib/typing.py | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/Lib/typing.py b/Lib/typing.py index d09b320..fda0b2d 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -1061,15 +1061,24 @@ class ForwardRef(_Final, _root=True): globalns = getattr( sys.modules.get(self.__forward_module__, None), '__dict__', globalns ) + + # type parameters require some special handling, + # as they exist in their own scope + # but `eval()` does not have a dedicated parameter for that scope. + # For classes, names in type parameter scopes should override + # names in the global scope (which here are called `localns`!), + # but should in turn be overridden by names in the class scope + # (which here are called `globalns`!) if type_params: - # "Inject" type parameters into the local namespace - # (unless they are shadowed by assignments *in* the local namespace), - # as a way of emulating annotation scopes when calling `eval()` - locals_to_pass = {param.__name__: param for param in type_params} | localns - else: - locals_to_pass = localns + globalns, localns = dict(globalns), dict(localns) + for param in type_params: + param_name = param.__name__ + if not self.__forward_is_class__ or param_name not in globalns: + globalns[param_name] = param + localns.pop(param_name, None) + type_ = _type_check( - eval(self.__forward_code__, globalns, locals_to_pass), + eval(self.__forward_code__, globalns, localns), "Forward references must evaluate to types.", is_argument=self.__forward_is_argument__, allow_special_forms=self.__forward_is_class__, |