title: How to detect and remove outliers from each column of pandas dataframe at one go?
body: <p>I've a pandas data frame with six columns and i know there are some outliers in each column.So i have these two lines of code which is pretty much doing what i want to do. But it's removing outliers from only one column of the dataframe. so what if i want to remove outliers from each column together??</p>
  
  <pre><code>df = pd.DataFrame({'stlines':np.random.normal(size=533)})
  df = df[np.abs(df.stlines-df.stlines.mean()) &lt;= (2*df.stlines.std())]
  </code></pre>
  
  <p>what would be the elegant way to do this?</p>