code: def get_mac_addr(mac_addr):
          
          mac_addr = bytearray(mac_addr)
          mac = b':'.join([('%02x' % o).encode('ascii') for o in mac_addr])
          return mac
docs: converts bytes to mac addr format
          :mac_addr: ctypes.structure
          :return: str
              mac addr in format
              11:22:33:aa:bb:cc