title: Python dictionary: Remove all the keys that begins with s
body: <p>I've got a dictionary like</p>
  
  <pre><code>dic = {'s_good': 23, 's_bad': 39, 'good_s': 34}
  </code></pre>
  
  <p>I want to remove all the keys that begins with 's_'</p>
  
  <p>So in this case first two will be removed.</p>
  
  <p>Is there any efficient way to do so?</p>