title: 'Check all boxes' Check box in Python
body: <p>Using python and tkinter I have an app that dynamically creates lots of check boxes (around 40) and i would like to add another one that preceeds them that can <strong>check all</strong> of the checkboxes</p>
  
  <p>An example of this is in email... when you want to delete large quanitities of email you can check the 'Select all' checkboxs.</p>
  
  <p>My question is how can I add this functionality to my python GUI app. I think it's to do with <code>chk_btn.config(state="")</code> but im not sure</p>
  
  <p>Any and all help appreciated!</p>