title: Pyqt prevent combobox change value
body: <p>I have four combo-box boxes that in <strong>PyQT4</strong>. If user change the value in first combo-box the values from second are altered and similarly if the value in second combo-box change, that results in the change of thirds combo-box and the same case for the fourth combo-box. What i want is when i change the value i first combo-box it should result in change of only second combo-box while does not effect the changes in third and fourth combo-box. How can i do this in <strong>PyQt</strong> ?</p>
  
  <p>I have <strong>changedIndex</strong> event setup on each combo-box. </p>