title: How to make a multidimension numpy array with a varying row size?
body: <p>I would like to create a two dimensional numpy array of arrays that has a different number of elements on each row.  </p>
  
  <p>Trying</p>
  
  <pre><code>cells = numpy.array([[0,1,2,3], [2,3,4]])
  </code></pre>
  
  <p>gives an error</p>
  
  <pre><code>ValueError: setting an array element with a sequence.
  </code></pre>