title: Error trying to call the backend module in pyusb. "AttributeError: 'module' object has no attribute 'backend'"
body: <p>I recently installed pyusb for this project, which is trying to attempt at writing to a <a href="https://www.thinkgeek.com/product/1690/" rel="nofollow noreferrer">USB LED Message Board</a> and received this error:</p>
  <p><code>AttributeError: 'module' object has no attribute 'backend'</code></p>
  <p>I don't know why this is, I checked the pyusb module files and it clearly has a folder named &quot;backend&quot; and inside has the correct files.</p>
  <p>Here's all of my code:</p>
  <pre><code>import usb.core
  import usb.util
  import sys
  
  backend = usb.backend.libusb01.get_backend(find_library=lambda C: &quot;Users\absolute\Desktop\libusb-win32-bin-1.2.6.0\lib\msvc_x64&quot;)
  
  #LED Display Message device identify
  MessageDevice = usb.core.find(idVendor=0x1D34, idProduct=0x0013, backend=backend)
  
  if MessageDevice is None:
      raise ValueError('LED Message Display Device could not be found.')
  
  MessageDevice.set_configuration()
  
  
  
  
  
  # get an endpoint instance
  cfg = MessageDevice.get_active_configuration()
  interface_number = cfg[(0,0)].bInterfaceNumber
  print interface_number
  alternate_settting = usb.control.get_interface(interface_number)
  intf = usb.util.find_descriptor(
      cfg, bInterfaceNumber = interface_number,
      bAlternateSetting = alternate_setting
  )
  
  ep = usb.util.find_descriptor(
      intf,
      # match the first OUT endpoint
      custom_match = \
      lambda e: \
          usb.util.endpoint_direction(e.bEndpointAddress) == \
          usb.util.ENDPOINT_OUT
  )
  
  assert ep is not None
  
  # write the data
  ep.write('\x00\x06\xFE\xBA\xAF\xFF\xFF\xFF')
  </code></pre>
  <p>Code to focus on:</p>
  <pre><code>backend = usb.backend.libusb01.get_backend(find_library=lambda C: &quot;Users\absolute\Desktop\libusb-win32-bin-1.2.6.0\lib\msvc_x64&quot;)
  </code></pre>
  <p>Also I've noticed in other code people don't have the backend at all.  But when I try to remove the backend part of my code it displays:</p>
  <pre><code>MessageDevice = usb.core.find(idVendor=0x1D34, idProduct=0x0013)
  File &quot;C:\Python27\lib\site-packages\usb\core.py&quot;, line 846, in find
  raise ValueError('No backend available')
  ValueError: No backend available
  </code></pre>
  <p>Some extra info:</p>
  <ul>
  <li>Windows 8 64bit</li>
  <li>Python 2.7</li>
  <li>pyusb-1.0.0a2</li>
  </ul>