title: How to highlight the last occurrence of a string in a text widget?
body: <p>I would like to highlight the last occurence of a pattern in a text widget (in Tkinter).</p>
  
  <p>Example: </p>
  
  <pre><code>pattern = 'ssi'
  string = 'ssiljkssilkjssi'
  </code></pre>
  
  <p>I want the last “ssi” to be in red and the rest of the text to stay in black. How can I do this?</p>