python通过建立长链接，获取动态ip，这种方式可以长时间保持连接

# 服务端
import socket
 
class UdpServer(object):
    def tcpServer(self):
        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
        sock.bind((‘0.0.0.0‘, 1060)) 
        
        while True:
            revcData, (remoteHost, remotePort) = sock.recvfrom(1024)
            print("[%s:%s] connect" % (remoteHost, remotePort)) 
            
            sendDataLen = sock.sendto("this is send  data from server".encode(), (remoteHost, remotePort))
            print("revcData: ", revcData)
            print("sendDataLen: ", sendDataLen)
            
        sock.close()
            
if __name__ == "__main__":
    udpServer = UdpServer()
    udpServer.tcpServer()

# 客户端
from socket import *
import time

# 设定目标地址
dest = (‘<broadcast>‘, 1060)  
s = socket(AF_INET, SOCK_DGRAM)
s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)
data = ‘Is client,time of {}‘.format(time.time())
str = s.sendto(data.encode(‘utf-8‘), dest)  # 发送广播
s.settimeout(30)  # 设置等待超时时间为30s
msg, addr = s.recvfrom(1024)  # recvfrom为阻塞方法
print(‘接收回复==服务端地址:{},响应内容:{}‘.format(addr, msg.decode(‘utf-8‘)))
s.close()