https://www.geeksforgeeks.org/difference-between-dir-and-vars-in-python/ vars(node) 只返回当前节点属性 dir(node) 不仅仅返回当前节点属性,还返回node节点的所有父亲节点的属性。 dir() Function: This function displays more attributes than vars() function, as it is not limited to an instance. It...