from __future__ import print_function
import socket
import time
from contextlib import closing

def main():
  local_address   = '192.168.0.1' # 送信側のPCのIPアドレス
  multicast_group = '239.255.0.1' # マルチキャストアドレス
  port = 4000

  with closing(socket.socket(socket.AF_INET, socket.SOCK_DGRAM)) as sock:

    # sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_LOOP, 0)
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, socket.inet_aton(local_address))

    count = 0
    while True:
      message = 'Hello world : {0}'.format(count).encode('utf-8')
      print(message)
      sock.sendto(message, (multicast_group, port))
      count += 1
      time.sleep(0.5)
  return

if __name__ == '__main__':
  main()