Getting USB Input using Python Program on Windows 8 - backend unavailable

0
votes

I am quite new to programming and have been trying to run a basic python program using IDLE on Windows 8 as seen on this page (usb device identification) I need to read a USB stick and return the vendor and product Ids (see below)

import usb  #import the usb package which contains all the PyUSB modules
busses = usb.busses() #Assign USB busses to a tuple (this is returned from legacy)
for bus in busses:
    devices = bus.devices
    for dev in devices:
        print "Device:", dev.filename
        print "  idVendor: %d (0x%04x)" % (dev.idVendor, dev.idVendor)
        print "  idProduct: %d (0x%04x)" % (dev.idProduct, dev.idProduct)

I’ve been using the PyUSB library: Pyusb- 1.0.0.0a2 (http://sourceforge.net/projects/pyusb/)

And the IDLE python text editor version 2.7.8 (https://www.python.org/downloads/)

Similarly to the other page, I keep getting returned a “backend unavailable” error. My folder structure is as follows (sorry about the excessive underscoring, they represent subfolders):

  • 27-11-14 (the folder containing my actual program: “27-11-14_busses.py”)
  • _________Build((came with the downloaded Pyusb-1.0.0.0a2))
  • _________docs (came with the downloaded Pyusb-1.0.0.0a2)
  • _________usb (came with the downloaded Pyusb-1.0.0.0a2)
  • __________________backend (which contains backends: libusb0, libusb1 and openusb)
  • _________DLLs
  • _________Doc
  • _________etc
  • _________include
  • _________Lib
  • _________Libs
  • _________tcl
  • _________tests
  • _________Tools

The problem seems to occur inside a file called “core.py” (in “usb” folder) for a user defined function called “find” This contains code for importing 3 different backends All 3 of these are inside my backend folder, but for some reason the program can’t find them

Can anyone see what the problem might be? Is my folder structure incorrect?

1
pythonusbbackend

1 Answers

0
votes

Have you run setup.py and properly installed PyUSB for your Python version? It seems like you are just extracting downloaded zip/tar to your folder? Correct me if I'm wrong, but if you do, that's not how you install modules in Python. If you want to learn more about module installing check this part of docs:

https://docs.python.org/2/install/