https://blog.wongcw.com/2018/12/10/python-%e6%88%90%e5%8a%9f%e4%b8%8a%e4%bd%8d%e6%ad%a3%e9%80%90%e6%bc%b8%e8%88%87java-%e6%8b%89%e9%96%8b%e5%b7%ae%e8%b7%9d/