title: shuffle vs permute numpy
body: <p>What is the difference between <code>numpy.random.shuffle(x)</code> and <code>numpy.random.permutation(x)</code>?</p>
  
  <p>I have read the doc pages but I could not understand if there was any difference between the two when I just want to randomly shuffle the elements of an array.</p>
  
  <p>To be more precise suppose I have an array <code>x=[1,4,2,8]</code>.</p>
  
  <p>If I want to generate random permutations of x, then what is the difference between <code>shuffle(x)</code> and <code>permutation(x)</code>?</p>