docstring_factory.py

import types


def attach_docstring(value, docstring: str):
    class_name = type(value).__name__
    class_bases = (type(value),)
    build_body = lambda ns: ns.update({"__doc__": docstring})
    return types.new_class(class_name, class_bases, exec_body=build_body)(value)


if __name__ == "__main__":
    delorean_speed = attach_docstring(88, "when this baby hits 88 miles per hour... you're gonna see some serious shit")

    assert isinstance(delorean_speed, type(88)), f"Expected an int. Got {type(delorean_speed)!r}"
    assert delorean_speed / 2 == 44
    assert delorean_speed.__doc__ == "when this baby hits 88 miles per hour... you're gonna see some serious shit"