title: Convert multidimensional list to multidimensional numpy.array
body: <p>I am having trouble converting a python list-of-list-of-list to a 3 dimensional numpy array. </p>
  
  <pre><code>a = [
     [ 
       [1,2,3,4], # = len 4
       ...
     ], # = len 58
     ...
  ] # = len 1245
  </code></pre>
  
  <p>when I call <code>a = np.array(a)</code> on it, it reports shape as <code>(1245,)</code> and I cannot reshape it. <code>a.reshape(1245,58,4)</code> It gives me the error: 
  <code>ValueError: cannot reshape array of size 1245 into shape (1245,58,4)</code> But If I print a[0] it gives me a 58 element list and a[0][0] gives me a 4 element list, as I expected, so the data is there.</p>
  
  <p>I see plenty of stack exchange posts wanting to flatten it, but I just want to make it into a numpy array in the shape that it already is. I don't know why <code>numpy.array()</code> is not seeing the other dimensions.</p>