title: How to sum 3 columns panda python
body: <p>I want to sum the value of 3 columns for example <code>3 4 10</code>  I want as a result <code>17</code>  not <code>3410</code>! 
  I did the following:</p>
  
  <pre><code>df2["OverAll"] = df2['reading'] + df2['math'] + df2['writing']
  </code></pre>
  
  <p>But it gives me the 3410 (put the 3 columns together!). </p>
  
  <p>Please help! </p>