Function _allow_reckless_class_checks

Lib/typing.py:1942–1950

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.

(depth=2)

    return None

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.
    """
    # 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 = {