title: Applying lambda functions to columns
body: <p>I have a dataframe df</p>
  
  <pre><code>   id   values
  1  34   ['de, fa qe', 'ml, fr']
  2  45   ['op er, qe', 'm, qn', 'asd, qwe, zxc'] 
  </code></pre>
  
  <p>I want to end with:</p>
  
  <pre><code>   id   values
  1  34   ['de, fa qe, ml, fr']
  2  45   ['op er, qe, m, qn, asd, qwe, zxc'] 
  </code></pre>
  
  <p>I'm thinking about using this function</p>
  
  <pre><code>merger=lambda x, y:x+y
  </code></pre>
  
  <p>But I can't figure out how to apply it.</p>
  
  <p>Thank you.</p>