raise + 自定义Exception

场景

退出多重for循环，break只能退出一层

class ReturnError(Exception):
    pass

def compare(dst, src):
  
    try:

        for dst_k, dst_v in dst_dict.items():
            if dst_k not in src_dict:
                raise ReturnError(msg)
            else:
                for dst_v_k, dst_v_v in dst_v.items():
                    if dst_v_v != src_dict[dst_k][dst_v_k]:
                        raise ReturnError(msg)
    except ReturnError as e:
        e
    except Exception as e:
        _e1 = str(traceback.format_exc())
        e, _e1
    finally:
        return flag, msg