title: numpy.product vs numpy.prod vs ndarray.prod
body: <p>I'm reading through the Numpy docs, and it appears that the functions <code>np.prod(...)</code>, <code>np.product(...)</code> and the <code>ndarray</code> method <code>a.prod(...)</code> are all equivalent. </p>
  
  <p>Is there a preferred version to use, both in terms of style/readability and performance? Are there different situations where different versions are preferable? If not, why are there three separate but very similar ways to perform the same operation?</p>