title: How to update values to the listbox under Combobox in ttk Python33
body: <p>When I create the Combobox, it has no items in the list. Now when I click on the dropdown button a function is called (via the postcommand option), but once in my function I don't know how to set the values in the listbox of the Combobox.</p>
  
  <p>Code something like this:</p>
  
  <pre><code>    #update list upon drop down
      self.cbox = Combobox(self, width = 10, postcommand = self.updtcblist)
  
      def updtcblist(self):
          list = self.getPortLst()
          self.cbox.getlistbox.set(list) #getlistbox doesn't work
  </code></pre>
  
  <p>Thanks,</p>
  
  <p>Harvey</p>