def METHOD_NAME(self, port_num):
    if port_num in self.qsfp_ports:
        self._port_name = "QSFP" + str(port_num - self.QSFP_PORT_START + 1)
    else:
        self._port_name = "SFP" + str(port_num - self.QSFP_PORT_END)
    return self._port_name