def listObjs(regex='Q', typ=None):
    """List all objects managed by python gc with class name matching regex.
    Finds 'Q...' classes by default."""
    if typ is not None:
        return [x for x in gc.get_objects() if isinstance(x, typ)]
    else:
        return [x for x in gc.get_objects() if re.match(regex, type(x).__name__)]