title: adding value to only a single column in pandas dataframe
body: <p>I have a dataframe and i need to add data only to a specific column</p>
  
  <p>DF</p>
  
  <pre><code>A  B  C
  1  2  3
  2  3  4
  a  d  f
  22 3  3
  </code></pre>
  
  <p>output :</p>
  
  <pre><code>A  B  C
  1  2  3
  2  3  4
  a  d  f
  22 3  3
  32
        34
  </code></pre>
  
  <p>I tried : <code>df['A'].append(pd.DataFrame([valuetoadd]), ignore_index=True)</code> where <code>valuetoadd</code> is a variable</p>