title: Python string formatting when string contains "%s" without escaping
body: <p>When formatting a string, my string may contain a modulo <code>"%"</code> that I do not wish to have converted.  I can escape the string and change each <code>"%"</code> to <code>"%%"</code> as a workaround.</p>
  
  <p>e.g.,  </p>
  
  <pre><code>'Day old bread, 50%% sale %s' % 'today!'  
  </code></pre>
  
  <p>output:  </p>
  
  <pre><code>'Day old bread, 50% sale today'
  </code></pre>
  
  <p>But are there any alternatives to escaping?  I was hoping that using a dict would make it so Python would ignore any non-keyword conversions.<br>
  e.g.,  </p>
  
  <pre><code>'Day old bread, 50% sale %(when)s' % {'when': 'today'}  
  </code></pre>
  
  <p>but Python still sees the first modulo <code>%</code> and gives a:  </p>
  
  <pre><code>TypeError: not enough arguments for format string
  </code></pre>