title: Pandas: Replace all values in column with column maximum
body: <p>I have the following dataframe</p>
  
  <pre><code>            NDQ        CFRI        NFFV        [more columns....]
  2002-01-24 92.11310000 57.78140000 90.95720000
  2002-01-25 57.97080000 91.05430000 58.19820000
  </code></pre>
  
  <p>I want to set all values in a column equal to the maximum value of the respective column.</p>
  
  <p>Desired output:</p>
  
  <pre><code>            NDQ        CFRI        NFFV        [more columns....]
  2002-01-24 92.11310000 91.05430000 90.95720000
  2002-01-25 92.11310000 91.05430000 90.95720000
  </code></pre>
  
  <p>I have attempted to map it out to the result of <code>df.max()</code>, but struggled with the implementation and also feel like there would be an easier solution available.</p>
  
  <p>Any help would be greatly appreciated.</p>