Function _has_original_dunder

IPython/core/guarded_eval.py:200–223

(
    value, allowed_types, allowed_methods, allowed_external, method_name
)

def _has_original_dunder(
    value, allowed_types, allowed_methods, allowed_external, method_name
):
    # note: Python ignores `__getattr__`/`__getitem__` on instances,
    # we only need to check at class level
    value_type = type(value)

    # strict type check passes → no need to check method
    if value_type in allowed_types:
        return True

    method = getattr(value_type, method_name, None)

    if method is None:
        return None

    if method in allowed_methods:
        return True

    for module_name, *access_path in allowed_external:
        if _has_original_dunder_external(value, module_name, access_path, method_name):
            return True

    return False


def _coerce_path_to_tuples(