title: Pandas - select dataframe columns if statistic is greater than certain value
body: <p>I have pandas dataframe <code>df</code>. I would like to select columns which have standard deviation grater than 1. Here is what I tried</p>
  
  <pre><code>df2 = df[df.std() &gt;1]
  df2 = df.loc[df.std() &gt;1] 
  </code></pre>
  
  <p>Both generated error. What am I doing wrong?</p>