bpo-44801: Check arguments in substitution of ParamSpec in Callable (GH-27585)

(cherry picked from commit 3875a69547)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
This commit is contained in:
Miss Islington (bot) 2021-08-04 13:36:01 -07:00 committed by GitHub
parent c2593b4d06
commit 536e35ae6a
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GPG key ID: 4AEE18F83AFDEB23
4 changed files with 89 additions and 37 deletions

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@ -174,6 +174,11 @@ def _type_check(arg, msg, is_argument=True, module=None):
return arg
def _is_param_expr(arg):
return arg is ... or isinstance(arg,
(tuple, list, ParamSpec, _ConcatenateGenericAlias))
def _type_repr(obj):
"""Return the repr() of an object, special-casing types (internal helper).
@ -228,7 +233,9 @@ def _prepare_paramspec_params(cls, params):
variables (internal helper).
"""
# Special case where Z[[int, str, bool]] == Z[int, str, bool] in PEP 612.
if len(cls.__parameters__) == 1 and len(params) > 1:
if (len(cls.__parameters__) == 1
and params and not _is_param_expr(params[0])):
assert isinstance(cls.__parameters__[0], ParamSpec)
return (params,)
else:
_check_generic(cls, params, len(cls.__parameters__))
@ -1031,7 +1038,13 @@ class _GenericAlias(_BaseGenericAlias, _root=True):
new_args = []
for arg in self.__args__:
if isinstance(arg, self._typevar_types):
arg = subst[arg]
if isinstance(arg, ParamSpec):
arg = subst[arg]
if not _is_param_expr(arg):
raise TypeError(f"Expected a list of types, an ellipsis, "
f"ParamSpec, or Concatenate. Got {arg}")
else:
arg = subst[arg]
elif isinstance(arg, (_GenericAlias, GenericAlias, types.UnionType)):
subparams = arg.__parameters__
if subparams:
@ -1129,8 +1142,7 @@ class _CallableGenericAlias(_GenericAlias, _root=True):
def __repr__(self):
assert self._name == 'Callable'
args = self.__args__
if len(args) == 2 and (args[0] is Ellipsis
or isinstance(args[0], (ParamSpec, _ConcatenateGenericAlias))):
if len(args) == 2 and _is_param_expr(args[0]):
return super().__repr__()
return (f'typing.Callable'
f'[[{", ".join([_type_repr(a) for a in args[:-1]])}], '
@ -1138,8 +1150,7 @@ class _CallableGenericAlias(_GenericAlias, _root=True):
def __reduce__(self):
args = self.__args__
if not (len(args) == 2 and (args[0] is Ellipsis
or isinstance(args[0], (ParamSpec, _ConcatenateGenericAlias)))):
if not (len(args) == 2 and _is_param_expr(args[0])):
args = list(args[:-1]), args[-1]
return operator.getitem, (Callable, args)
@ -1865,8 +1876,7 @@ def get_args(tp):
if isinstance(tp, (_GenericAlias, GenericAlias)):
res = tp.__args__
if (tp.__origin__ is collections.abc.Callable
and not (res[0] is Ellipsis
or isinstance(res[0], (ParamSpec, _ConcatenateGenericAlias)))):
and not (len(res) == 2 and _is_param_expr(res[0]))):
res = (list(res[:-1]), res[-1])
return res
if isinstance(tp, types.UnionType):