How do I switch backends in libusb for python?

问题

I am using pyusb and according to the docs it runs on any one of three backends. libusb01 libusb10 and openusb. I have all three backends installed. How can I tell which backend it is using and how can I switch to a different one?

回答1:

I found the answer by looking inside the usb.core source file.

You do it by importing the backend and then setting a parameter inside the find method of usb.core. Like so:

import usb.backend.libusb1 as libusb1
import usb.backend.libusb0 as libusb0
import usb.backend.openusb as openusb

and then any one of:

devices = usb.core.find(find_all=1, backend=libusb1.get_backend() )    
devices = usb.core.find(find_all=1, backend=libusb0.get_backend() )    
devices = usb.core.find(find_all=1, backend=openusb.get_backend() )

This assumes you are using pyusb-1.0.0a3. For 1.0.0a2 the libs are called libusb10, libusb01 and openusb. Of course, you'd only need to import the one you want.

来源：https://stackoverflow.com/questions/19189194/how-do-i-switch-backends-in-libusb-for-python