title: Unset layout from QWidget in pyside
body: <p>I have a problem to set a new layout in my QWidget object. I start to set one type of layout when the app exec, and I want to change it when the button is pressed with a new layout. In the documentation of PySide I read this:</p>
  
  <blockquote>
    <p>Sets the layout manager for this widget to layout.</p>
    
    <p>If there already is a layout manager installed on this widget,
    PySide.QtGui.QWidget won’t let you install another. You must first
    delete the existing layout manager (returned by
    PySide.QtGui.QWidget.layout() ) before you can call
    PySide.QtGui.QWidget.setLayout() with the new layout.</p>
  </blockquote>
  
  <p>But how can I delete the existing layout manager? What are the methods which I must apply on my QWidget object? </p>