title: Python3 custom view objects
body: <p>Is it possible to implement custom view objects in Python 3?</p>
  
  <p>According to the documentation:</p>
  
  <blockquote>
    <p>The objects returned by dict.keys(), dict.values() and dict.items() are view objects. They provide a dynamic view on the dictionary’s entries, which means that when the dictionary changes, the view reflects these changes.</p>
  </blockquote>
  
  <p>So is it possible to somehow create custom view objects? </p>
  
  <p>I was searching very long any information about it, but the only explanations I found are <strong>what</strong> are the views, not how to <strong>create custom</strong> or <strong>how they are implemented</strong> (their internal mechanism).</p>