title: Flask's request.files.getlist for isn't empty when field is not submitted
body: <p>I want to get a list of uploaded photos by using: <code>photos = request.files.getlist("photo")</code>. However, if I haven't selected any files in the browser, the <code>photos</code> value is not empty like other fields.</p>
  
  <p>I want to check if no files are submitted by doing:</p>
  
  <pre><code>if not photos:
     pass
  </code></pre>
  
  <p>But there's always an empty <code>FileStorage</code> object even when no files are submitted:</p>
  
  <pre><code>request.files.getlist("photo")
  [&lt;FileStorage: '' ('application/octet-stream')&gt;]
  </code></pre>
  
  <p>Why is it there? How can I check that no files were uploaded if the list is never empty?</p>