title: What is type <U12?
body: <p>I was using <code>pandas</code> and <code>numpy</code> to process some data until I got two similar output of arrays:</p>
  
  <pre><code>array(['french', 'mexican', 'cajun_creole', ..., 'southern_us', 'italian',
         'thai'], dtype='&lt;U12')
  
  array(['french', 'mexican', 'cajun_creole', ..., 'jamaican', 'italian',
     'thai'], dtype=object)
  </code></pre>
  
  <p>I don't see the difference, what is <code>&lt;U12</code>?</p>