title: PyQt4 - QString object has no attribute 'isEmpty''
body: <p>I'm trying to use a PyQt file on Python 3.4, that was originally targeted for Python 2.7. I don't have 2.7 installed, but I trust the code originally worked.</p>
  
  <p>The error I'm seeing is on the <code>strVal</code> returned from <code>QInputDialog.getItem</code>:</p>
  
  <pre><code>import  random, sys, queue, serial, glob, os, csv, time
  import  PyQt4.Qwt5     as Qwt
  from    PyQt4.QtCore   import *  
  from    PyQt4.QtGui    import *
  
  ...
  
  strVal , ok = QInputDialog.getItem(self, 'Select a port',
      'Serial port:', ports, 0, False)
  
  if ok and not strVal.isEmpty():
      self.portname.setText(strVal)            
  </code></pre>
  
  <p>From the documentation, <code>QInputDialog.getItem</code> should return a <code>QString</code> (not just a string), and <code>QString</code> objects have the attribute <code>.isEmpty()</code>.  </p>
  
  <p>Since I get the no <code>.isEmpty()</code> attribute, is it somehow not importing <code>QString</code>?</p>