title: Insert list into cells which meet column conditions
body: <p>Consider <code>df</code></p>
  
  <pre><code>   A  B  C
  0  3  2  1
  1  4  2  3
  2  1  4  1
  3  2  2  3
  </code></pre>
  
  <p>I want to add another column <code>"D"</code> such that D contains different Lists based on conditions on <code>"A"</code>, <code>"B"</code> and <code>"C"</code></p>
  
  <pre><code>   A  B  C  D
  0  3  2  1  [1,0]
  1  4  2  3  [1,0]
  2  1  4  1  [0,2]
  3  2  2  3  [2,0]
  </code></pre>
  
  <p>My code snippet looks like:</p>
  
  <pre><code>df['D'] = 0
  df['D'] = df['D'].astype(object)
  
  df.loc[(df['A'] &gt; 1) &amp; (df['B'] &gt; 1), "D"] = [1,0]
  df.loc[(df['A'] == 1) , "D"] = [0,2]
  df.loc[(df['A'] == 2) &amp; (df['C'] != 0) , "D"] = [2,0]
  </code></pre>
  
  <p>When I try to run this code it throws the following error:</p>
  
  <pre><code>ValueError: Must have equal len keys and value when setting with an iterable
  </code></pre>
  
  <p>I have converted the column into <code>Object</code> type as suggested <a href="https://stackoverflow.com/questions/26483254/python-pandas-insert-list-into-a-cell">here</a> but still with error.</p>
  
  <p>What I can infer is that pandas is trying to iterate over the elements of the list and assigns each of those values to the cells where as I am trying to assign the entire list to all the cells meeting the criterion.</p>
  
  <p>Is there any way I can assign lists in the above fashion?</p>