title: How to get the last number from list in python
body: <p>Suppose I have the list as </p>
  
  <pre><code>a = [0.0021, 0.12, 0.1224, 0.22]
  </code></pre>
  
  <p>I have to extract the last number from the above list, so my answer should be <code>0.22</code> without using <code>a[3]</code>, because the number of the elements in the list always keep changing.</p>