title: ctypedef in Cython with numpy: what is right convention?
body: <p>In Cython when using numpy, what is the point of writing:</p>
  
  <pre><code>cimport numpy as np
  import numpy as np
  ctypedef np.int_t DTYPE_t
  </code></pre>
  
  <p>and then using <code>DTYPE_t</code> everywhere instead of just using <code>np.int_t</code>? Does the <code>ctypedef</code> actually do anything differently in the resulting code here?</p>