udp多播组播

import socket  ,struct,time# 组播地址和端口号  
MCAST_GRP = '239.0.0.1'  
MCAST_PORT = 8888  # 创建UDP socket对象  
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)  # 绑定socket对象到本地端口号  
# sock.bind((MCAST_GRP, MCAST_PORT))  # 加入组播组  
mreq = struct.pack("4sl", socket.inet_aton(MCAST_GRP), socket.INADDR_ANY) # 使用INADDR_ANY来指定任何网络接口  
sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)  # 发送组播消息  
message = b'Hello, multicast!'  
sock.sendto(message, (MCAST_GRP, MCAST_PORT))  
print('aa')
cnt = 0
# 接收组播消息  
while True:  message = 'Hello, zym!'  +str(cnt)print(message)message=message.encode('gbk')cnt = cnt+1sock.sendto(message, (MCAST_GRP, MCAST_PORT))  time.sleep(1)#data, addr = sock.recvfrom(1024)  #print('Received message:', data)

实测wifi环境中1发两收，1s发送一次。接收端的丢包率很严重。