title: python pyusb import usb.core doesn't work
body: <p>I am following the tutorial(http://pyusb.sourceforge.net/docs/1.0/tutorial.html)</p>
  
  <p>I am on windows xp sp3, 
  my python version is 2.7 and I downloaded and installed the pyusb-1.0.0-a1.zip</p>
  
  <p>and libusb-win32-bin-1.2.4.0.zip</p>
  
  <pre><code>import usb
  </code></pre>
  
  <p>works fine</p>
  
  <p>but </p>
  
  <pre><code>import usb.core
  </code></pre>
  
  <p>doesn't working at all </p>
  
  <p>it says </p>
  
  <pre><code>Traceback (most recent call last):
    File "D:\py\usb.py", line 1, in &lt;module&gt;
      from usb import core
    File "D:\py\usb.py", line 1, in &lt;module&gt;
      from usb import core
  ImportError: cannot import name core
  </code></pre>
  
  <p>any solution?</p>
  
  <p>thanks!</p>
  
  <p>p.s.
  "from usb import core"
  this make</p>
  
  <pre><code>Traceback (most recent call last):
    File "D:\py\usb.py", line 1, in &lt;module&gt;
      from usb import core
    File "D:\py\usb.py", line 1, in &lt;module&gt;
      from usb import core
  ImportError: cannot import name core
  </code></pre>
  
  <p>full source code is here</p>
  
  <pre><code>from usb import core
  #find device
  dev = usb.core.find(idVendor=0x1516, idProduct=0x8628)
  #found?
  if dev is None :
          raise ValueError('device not found')
  
  #set the active config. with no args, the first config will be the active one
  
  dev.set_configuration()
  
  #get an end point instance
  ep = usb.util.find_descriptor(
      dev.get_interface_altsetting(), #first interface
      #match the first Out Endpoint
      custom_match = \
          lambda e: \
              usb.util.endpoint_direction(e.bEndpointAddress) == \
              usb.util.ENDPOINT_OUT)
  assert ep is not None
  
  while(1):
      ep.write(0x5553424350DDBC880000000000000600000000000000000000000000000000)
      ep.write(0x5553425350ddbc880000000000)
  </code></pre>