https://blog.wongcw.com/2020/01/15/%e5%a0%b1%e5%91%8a%e9%a1%af%e7%a4%ba%ef%bc%9a50%ef%bc%85-%e7%9a%84%e5%85%ac%e5%8f%b8%e6%b2%92%e6%9c%89%e9%87%9d%e5%b0%8dpython-2-eol-%e7%9a%84%e8%a8%88%e5%8a%83/