title: Converting a numpy string array to integers in base-16
body: <p>I am looking for a way to convert an array of strings in numpy to the integers they represent in hexadecimal. So in other words, the array version of:</p>
  
  <pre><code>int("f040", 16)
  </code></pre>
  
  <p>I can convert a string array to integers base-10 by calling arr.astype(numpy.int32), but I can't see any obvious way to convert them base-16. Does anyone know of a way to do this?</p>