david@david-linux:~/python$ sudo python pyusb_03.py 
[sudo] password for david: 
Device was found
----------------
Configuration of the device:
bConfigurationValue: 1
	bInterfaceNumber: 0
	bAlternateSetting: 0
	bLength: 9
		bEndpointAddress: 129
		bEndpointAddress: 2
Traceback (most recent call last):
  File "pyusb_03.py", line 33, in <module>
    dev.set_configuration()
  File "/usr/local/lib/python2.7/dist-packages/usb/core.py", line 530, in set_configuration
    self._ctx.managed_set_configuration(self, configuration)
  File "/usr/local/lib/python2.7/dist-packages/usb/core.py", line 92, in managed_set_configuration
    self.backend.set_configuration(self.handle, cfg.bConfigurationValue)
  File "/usr/local/lib/python2.7/dist-packages/usb/_debug.py", line 52, in do_trace
    return f(*args, **named_args)
  File "/usr/local/lib/python2.7/dist-packages/usb/backend/libusb10.py", line 455, in set_configuration
    _check(_lib.libusb_set_configuration(dev_handle, config_value))
  File "/usr/local/lib/python2.7/dist-packages/usb/backend/libusb10.py", line 357, in _check
    raise USBError(_str_error[retval.value])
usb.core.USBError: Resource busy
david@david-linux:~/python$