title: Get a subarray from a numpy array based on index
body: <p>I have a numpy array vector, and I want to get a subset based on the indexes:</p>
  
  <pre><code>import numpy as np
  input=np.array([1,2,3,4,5,6,7,8,9,10])
  index=np.array([0,1,0,0,0,0,1,0,0,1])
  </code></pre>
  
  <p>what is a pythonic way to get out output=[2,7,10]?</p>