code: def str_to_mac(mac_string):
      
      sp = mac_string.split(':')
      mac_string = ''.join(sp)
      return binascii.unhexlify(mac_string)
docs: Convert a readable string to a MAC address
  
             Args:
                 mac_string (str): a readable string (e.g. '01:02:03:04:05:06')
             Returns:
                 str: a MAC address in hex form