title: Sort a string in lexicographic order python
body: <p>I want to sort a string to a list in lexicographic order as</p>
  
  <pre><code>str='aAaBbcCdE'
  </code></pre>
  
  <p>to </p>
  
  <pre><code>['A','a','a','B','b','C','c','d','E']
  </code></pre>
  
  <p>but <code>sorted()</code> gives me this output:</p>
  
  <pre><code>['A','B','C','E','a','a','b','c','d']
  </code></pre>
  
  <p>How can I sort lexicographically?</p>