Python: Row wise operation in a list of lists : <p>I have a list of lists</p>

<pre><code>[[1,2,3,4,5],
[6,7,8,9,10],
[11,12,13,14,15],
[16,17,18,19,20]]
</code></pre>

<p>How do I create a list that subtracts the next row item from the current row item
in this case: (7-2),(12-7),(17-12) to get a another list</p>

<pre><code>[5,5,5]
</code></pre>
