socket.gaierror: [Errno 8] nodename nor servname provided, or not known

當執行下面的 script 會出錯：

import socket
  (hostname, aliaslist, ipaddrlist) = socket.gethostbyname_ex(socket.gethostname())

Error message:

socket.gaierror: [Errno 8] nodename nor servname provided, or not known

真的滿奇怪的，只好改從 netifaces 來拿 ip

python 取得 ip address 的方法
https://stackoverflow.max-everyday.com/2017/02/python-netifaces/