title: Python 3.1 code and error
body: <p>64-bit VISTA<br>
  Python 3.1</p>
  
  <pre><code>from urllib import request
  a = request.urlopen('http://www.marketwatch.com/investing/currency/CUR_USDYEN').read(20500)
  b = a[19000:20500]
  idx_pricewrap = b.find('pricewrap')
  context = b[idx_pricewrap:idx_pricewrap+80]
  idx_bgLast = context.find('bgLast')
  rate = context[idx_bgLast+8:idx_bgLast+15]
  print(rate)
  </code></pre>
  
  <pre>
  Traceback (most recent call last):
   File "c:\P31Working\test_urllib.py", line 4, in 
     idx_pricewrap = b.find('pricewrap')
  TypeError: expected an object with the buffer interface
  Process terminated with an exit code of 1
  </pre>
  
  <p>I have NO idea what that error means.  </p>
  
  <p>Please help.</p>