title: How to change Qtablewidget's specific cells background color in pyqt
body: <p>I am new in pyqt4 and I can't figure out how to do this. I have a QtableWidget with data in it. I want to  change some background color of the tableWidget's cells.  </p>
  
  <p>I tried <code>self.tableWidget.item(3, 5).setBackground(QtGui.QColor(100,100,150))</code> and it returns this error:</p>
  
  <blockquote>
    <p>AttributeError: 'NoneType' object has no attribute 'setBackground'</p>
  </blockquote>
  
  <p>What should I do? </p>