traceback.py 文件源码

def print_last(limit=None, file=None, chain=True):
    """This is a shorthand for 'print_exception(sys.last_type,
    sys.last_value, sys.last_traceback, limit, file)'."""
    if not hasattr(sys, "last_type"):
        raise ValueError("no last exception")
    if file is None:
        file = sys.stderr
    print_exception(sys.last_type, sys.last_value, sys.last_traceback,
                    limit, file, chain)