Python3

mac.py

import fcntl, struct, socket

def getHwAddr(ifname):
    'Return MAC address of given NIC'
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    try:
        info = fcntl.ioctl(s.fileno(), 0x8927,
                struct.pack('256s', bytes(ifname[:15], 'ascii')))
        return ''.join(['%02x:' % char for char in info[18:24]])[:-1]
    except OSError:
        return None
    finally:
        s.close()
if __name__ == "__main__":
    print(getHwAddr('eth0'))