nikon.py 文件源码

def session(self):
        '''
        Manage Nikon session with context manager.
        '''
        # When raw device, do not perform
        if self.__no_polling:
            with super(Nikon, self).session():
                yield
            return
        # Within a normal PTP session
        with super(Nikon, self).session():
            # launch a polling thread
            self.__event_queue = Queue()
            self.__nikon_event_proc = Thread(
                name='NikonEvtPolling',
                target=self.__nikon_poll_events
            )
            self.__nikon_event_proc.daemon = False
            atexit.register(self._nikon_shutdown)
            self.__nikon_event_proc.start()

            try:
                yield
            finally:
                self._nikon_shutdown()