title: how to fill missing values with average of each column
body: <p><a href="https://i.stack.imgur.com/DBDpf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DBDpf.png" alt="my table"></a></p>
  
  <pre><code>   y12N=y12N.fillna(y12N.mean())
  </code></pre>
  
  <p>I have tried this among other things, this isn't filling any  data to my columns as the table stays the way it is. NaN values are np.NaN values.</p>