title: How to extract the n-th maximum/minimum value in a column of a DataFrame in pandas?
body: <p>I would like to obtain the n-th minimum or the n-th maximum value from numerical columns in the <code>DataFrame</code> in pandas.</p>
  
  <p>Example:</p>
  
  <pre><code>df = pd.DataFrame({'a': [3.0, 2.0, 4.0, 1.0],'b': [1.0, 4.0 , 2.0, 3.0]})
  
       a    b
  0  3.0  1.0
  1  2.0  4.0
  2  4.0  2.0
  3  1.0  3.0
  </code></pre>
  
  <p>The third largest value in column <code>a</code> is 2 and the second smallest value in column <code>b</code> is also 2.</p>