title: Replacing "tokens" in Python string with alternate values
body: <p>Imagine a script that receives a string:</p>
  
  <p><code>http://whatever.org/?title=@Title@&amp;note=@Note@</code></p>
  
  <p>...and a list of tokens:</p>
  
  <p><code>['arg:Title=SampleTitle', 'arg:Note=SampleNote']</code></p>
  
  <p>What is the most Pythonic way to interpolate those tokens into the string, such that, using the above example, the following is produced:</p>
  
  <p><code>http://whatever.org/?title=SampleTitle&amp;note=SampleNote</code></p>
  
  <p>I've considered:</p>
  
  <ol>
  <li><p>Loop through the list and, for every string it contains, split out the token name, and do a regex replace on every instance of <code>@TOKEN_NAME</code> found; and</p></li>
  <li><p>Use some sort of templating mechanism (similar to what one can do with Ruby's <code>ERB.template</code>).</p></li>
  </ol>