title: How to sum every element in a numpy array divisible by 5 using vectorization?
body: <p>I am looking for a vectorization method for summing all elements of a numpy array that is evenly divisible by 5.</p>
  
  <p>For example, if I have</p>
  
  <pre><code>test = np.array([1,5,12,15,20,22])
  </code></pre>
  
  <p>I want to return 40.  I know about the np.sum method, but is there a way to do this using vectorization given the X%5 == 0 conditional?</p>