How do I sum the columns in 2D list?
<p>Say I've a Python 2D list as below:</p>

<pre><code>my_list =  [ [1,2,3,4],
             [2,4,5,6] ]
</code></pre>

<p>I can get the row totals with a list comprehension:</p>

<pre><code>row_totals = [ sum(x) for x in my_list ]
</code></pre>

<p>Can I get the column totals without a double <code>for</code> loop? Ie, to get this list:</p>

<pre><code>[3,6,8,10]
</code></pre>
