Python: get mac address of a interface

get_mac_address.py

import socket
import fcntl
import struct

def getHwAddr(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    info = fcntl.ioctl(s.fileno(), 0x8927,  struct.pack('256s', ifname[:15]))
    return ''.join(['%02x:' % ord(char) for char in info[18:24]])[:-1]