问python如何获取指定端口的访问IP？

import os
port = ":3389"
for n in os.popen("netstat -n").read().split("\n"):
    if n.find(port) > -1:
        aa1=(n.split(":")[0].split(" ")[-1])
        with open('mstsc.log', 'w+', encoding="gbk") as f:
           f.writelines(aa1)