title: What does 'result[::-1]' mean?
body: <p>I am just coming cross the following python code which confuses me a bit:</p>
  
  <pre><code> res = self.result[::-1].encode('hex')
  </code></pre>
  
  <p>The encode stuff is pretty clear, it should be represented as hex value. However, what
  does this self.result[::-1] mean, especially the colons? </p>