title: Python QPushButton setIcon: put icon on button
body: <p>I want to put an in ICON into a push button.. the code should work like that:</p>
  
  <pre><code>    self.printButton = QtGui.QPushButton(self.tab_name)
      self.printButton.setIcon(QtGui.QPixmap('printer.tif'))
      self.printButton.setGeometry(QtCore.QRect(1030, 500, 161, 61))
  </code></pre>
  
  <p>But instead, it gives the error message:</p>
  
  <pre><code>    TypeError: argument 1 of QAbstractButton.setIcon() has an invalid type
  </code></pre>
  
  <p>What is missing here?</p>
  
  <p>All comments and suggestions are highly appreciated.</p>