title: Unable to get length of QList despite docs telling me i can
body: <p>I'm working on a small plugin for QGIS 3.12+ and regardless of what i try i'm unable to perform the simple task of retrieving the number of items in a QList that's returned by QListWidget.selectedItems() </p>
  
  <p>I'm not well versed in python, but have read through the <a href="https://doc.qt.io/qt-5/qlist.html" rel="nofollow noreferrer">docs</a> and tried each of the below with all of them failing.</p>
  
  <p>What am i missing?</p>
  
  <pre><code>#Returns items as i can loop though them with: for item in selected:
  selected = self.dlg.qListWidgetLayers.selectedItems()
  
  #TypeError: count() takes exactly one argument (0 given)
  #Docs claim there's a count that doesn't need the parameter...
  intTotal = selected.count()
  
  #AttributeError: 'list' object has no attribute 'size'
  intTotal = selected.size()
  
  #AttributeError: 'list' object has no attribute 'length'
  intTotal = selected.length()
  
  #AttributeError: 'list' object has no attribute 'len'
  intTotal = selected.len() #&lt;- This attempt is incorrect, should actually be len(selected)
  
  </code></pre>