title: 'IndexError: tuple index out of range' whith str.format
body: <p>What am I doing wrong?</p>
  
  <pre><code>print('script executed in {time}{1:.2f} seconds'.format(time=elapsed_time))
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>IndexError: tuple index out of range
  </code></pre>
  
  <p>Expected output:</p>
  
  <pre><code>script executed in 0.12 seconds
  </code></pre>