After running a python code for usb device following error is occured
Traceback (most recent call last):
File "test1.py", line 6, in
dev = usb.core.find(idVendor=0x1d6b, idProduct=0x0001)
File "/usr/lib/python2.7/site-packages/usb/core.py", line 1263, in find
raise NoBackendError('No backend available')
usb.core.NoBackendError: No backend available