Use a context manager for claiming an interface?

[mfreeborn]

I've just found this library, having been struggling along with a different USB library that wraps libusb, and the modern API and documentation is a real breath of fresh air.

I wonder if claiming/releasing an interface would match nicely with the concept of context managers?

device = usbx.find_device(0x1234)
device.open()

with device.claim_interface(0):  # claim interface 0
    # do stuff with the interface
    pass

# the claim on the interface has no been released
device.close()

This could help ensure that an interface isn't held onto accidentally if an unhandled exception occurs, for example.

I'm not familiar with the innards of the library to know if this would be a trivial/valid interface to adopt.

Some idea could extend to the open/close methods

[manuelbl]

Thanks for your interest in usbx and your suggestion.

Neither claiming and releasing interfaces nor opening and closing the device are prime candidates for context manager. But it could still be worthwhile for certain cases.

The reason they are not prime candidates is that claiming and releasing often happens in two different places. That's the case if the interface is claimed in the callback function called when a device is connected in and released in the disconnect callback function.

Furthermore, releasing an interface if the device has already been disconnected leads to an error. So this case would also need to be investigated. Possibly, the current behavior should be changed.

I will look into it. It shouldn't be difficult to add.