def clear_data(self):
        """
        clear all data (included: user, attendance report, finger database)

        :return: bool
        """
        command = const.CMD_CLEAR_DATA
        command_string = ''
        cmd_response = self.__send_command(command, command_string)
        if cmd_response.get('status'):
            self.is_connect = False
            self.next_uid = 1
            return True
        else:
            raise ZKErrorResponse("can't clear data")
clear all data (included: user, attendance report, finger database)

        :return: bool