title: Numpy's loadtxt(): OverflowError: Python int too large to convert to C long
body: <p>I'm trying to load a matrix from a file using <code>numpy</code>. When I use any <code>dtype</code> other than <code>float</code> I get this error:</p>
  
  <p><code>OverflowError: Python int too large to convert to C long</code> </p>
  
  <p>The code: 
  <code>X = np.loadtxt(feats_file_path, delimiter=' ', dtype=np.int64 )</code></p>
  
  <p>The problem is that my matrix has only integers and I can't use a <code>float</code> because the first column in the matrix are integer "keys" that refer to node ids. When I use a <code>float</code>, numpy "rounds" the integer id into something like 32423e^10, and I don't want this behavior.</p>
  
  <p>So my questions:</p>
  
  <ol>
  <li><p>How to solve the OverflowError?</p></li>
  <li><p>If it's not possible to solve, then how could I prevent numpy from doing that to the ids?</p></li>
  </ol>