title: How can I sort my number list in Python?
body: <pre><code>list = ['c:8', 'c:9', 'c:13', 'c:19', 'c:2', 'c:3', 'c:0', 'c:1', 'c:6', 'c:7', 'c:4', 'c:5', 'c:14', 'c:18', 'c:17', 'c:12', 'c:15', 'c:11', 'c:10', 'c:16', 'c:20']
  </code></pre>
  
  <p>I used "sorted()" but get this result</p>
  
  <pre><code>['c:0', 'c:1', 'c:10', 'c:11', 'c:12', 'c:13', 'c:14', 'c:15', 'c:16', 'c:17', 'c:18', 'c:19', 'c:2', 'c:20', 'c:3', 'c:4', 'c:5', 'c:6', 'c:7', 'c:8', 'c:9']
  </code></pre>
  
  <p>But what I want is</p>
  
  <pre><code>['c:0', 'c:1', 'c:2', 'c:3', 'c:4', 'c:5', 'c:6', 'c:7', 'c:8', 'c:9', 'c:10', 'c:11', 'c:12', 'c:13', 'c:14', 'c:15', 'c:16', 'c:17', 'c:18', 'c:19','c:20']
  </code></pre>
  
  <p>Besides getting what I want, I want why <code>sorted()</code> could not work.</p>