title: Adding a list of lists in a pandas dataframe column
body: <p>I have a data frame like this </p>
  
  <pre><code>A  B   C 
  0  1   2
  1  6   5
  </code></pre>
  
  <p>I need to add a list of lists in the 4th column of the dataframe . So that it becomes </p>
  
  <pre><code>A  B   C   D
  0  1   2   [[4,-0.05],[0.03,[-0.02,0.02]],[0.01,-0.03]]
  1  6   5   [[4,-0.35],[0.07,[-0.02,0.02]],[0.91,-0.03]]   
  </code></pre>
  
  <p>Please note the list of lists in column D. I am unable to find a way to add this type of column data to pandas dataframe</p>
  
  <p>Appreciate any help. Thanks in advance</p>