Python 3 SQM-LE Finder

findsqmle.py

#!/usr/bin/python                    

import socket, time, signal, sys

def signal_handler(signal, frame):
  print('\nCtrl-C received from keyboard - script exiting')
  sys.exit(0)

signal.signal(signal.SIGINT, signal_handler)

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setblocking(False)                               
if hasattr(socket,'SO_BROADCAST'):
  s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)

s.sendto(b'\x00\x00\x00\xf6', ("255.255.255.255", 30718))
buf=''

starttime = time.time()
print("Looking for replies; press Ctrl-C to stop.")
while True:
    try:
        ( buf, addr ) = s.recvfrom(30)
    except:
        #Timeout in seconds. Allow all devices time to respond
        if time.time()-starttime > 3:
            break
        pass
    else:
        if buf[3]==0xF7:
            print("Received from %s: MAC: %s" % (addr, ":".join("{0:02X}".format(x) for x in buf[24:30])))