由于Python绑定模拟了逻辑接口，所以不可能不通过一个服务来发送信号。

Because the Python bindings model the logical interface, it is not possible to send a signal without it coming from a service. So this example also creates a service.

youdao

Now I could do this pretty easily in just by reasoning through it; right?

我可以轻松地这样做,通过逻辑推理，对不？

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