def gen_mac(prefix='AC:DE:48'):
 return '{0}:{1:02X}:{2:02X}:{3:02X}'.format(prefix, random.randint(0, 255), random.randint(0, 255), random.randint(0, 255))

def gen_mac ( prefix = 'AC:DE:48' ) : return '{0}:{1:02X}:{2:02X}:{3:02X}' . format ( prefix , random . randint ( 0 , 255 ) , random . randint ( 0 , 255 ) , random . randint ( 0 , 255 ) )
generates a mac address with the defined oui prefix .