title: How to create collapsible box in PyQt
body: <p>I am using PyQt4, and I am trying to create a collapsible box where it will contains a couple of child widgets where the child widgets are already created and layout using a <code>QVboxLayout</code></p>
  
  <p>How do I go about creating it? Currently I am unable to find any commands eg. <code>QCollapseBox</code> etc.</p>
  
  <p>If it is not expanded:</p>
  
  <pre><code>+ Collapsible Box Header
  </code></pre>
  
  <p>If expanded:</p>
  
  <pre><code>- Collapsible Box Header
  |- Widget01
  |- Widget02
  </code></pre>
  
  <p>Where there is a + or - sign, or an arrow sign that can helps determine if it has been expanded or not</p>