title: Format string dynamically
body: <p>If I want to make my formatted string dynamically adjustable, I can change the following code from</p>
  
  <pre><code>print '%20s : %20s' % ("Python", "Very Good")
  </code></pre>
  
  <p>to</p>
  
  <pre><code>width = 20
  print ('%' + str(width) + 's : %' + str(width) + 's') % ("Python", "Very Good")
  </code></pre>
  
  <p>However, it seems that string concatenation is cumbersome here. Any other way to simplify things?</p>