import select, socket

port = 50000# where do you expect to get a msg?
bufferSize = 1024# whatever you need

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
#s.bind(("<broadcast>", port))
s.bind(('', port))
s.setblocking(0)

while True:
    result = select.select([s],[],[])
    msg = result[0][0].recv(bufferSize)
    print msg