def format_stack(f=None, limit=None):
    """Shorthand for 'format_list(extract_stack(f, limit))'."""
    if f is None:
        try:
            raise ZeroDivisionError
        except ZeroDivisionError:
            f = sys.exc_info()[2].tb_frame.f_back
    return format_list(extract_stack(f, limit))
Shorthand for 'format_list(extract_stack(f, limit))'.