title: How would I sum a multi-dimensional array in the most succinct python?
body: <p>The closest was this one <a href="https://stackoverflow.com/questions/3223043/how-do-i-sum-the-columns-in-2d-list">summing columns</a>.</p>
  
  <p>So I'll do something similar in my question:</p>
  
  <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>In one line, how can I sum the entire 2d-array?</p>
  
  <pre><code>27
  </code></pre>