title: Error "AttributeError: 'unicode' object has no attribute 'read'" on file upload
body: <p>I'm using Pylons to upload an image and store it to disk:</p>
  
  <pre><code> &lt;form method="post"&gt;
   &lt;input type="file" name="picture" enctype="multipart/form-data" /&gt;
   &lt;/form&gt;
  </code></pre>
  
  <p>Then in my controller:</p>
  
  <pre><code> if 'picture' in request.POST:
  
       i = ImageHandler()
  
       #Returns full path of image file
       picture_file = i.makePath()
  
       shutil.copyfileobj(request.POST['picture'],picture_file)
  </code></pre>
  
  <p>But I receive the error:
  AttributeError: 'unicode' object has no attribute 'read'</p>
  
  <p>What's going on here?  Thanks for your help.</p>