title: Creating a list of 6 every possible combination
body: <p>How would I create a list of 6 columns from a dataframe of 21 columns. I need to create every single combination possible and store these combinations is a dataframe. </p>
  
  <p>Suppose</p>
  
  <pre><code>lst = ['c1', 'c2', 'c3', 'c4','c5', 'c6', 'c7','c8', 'c9', 'c10', 'c11','c12', 'c13', 'c14','c15', 'c16', 'c17', 'c18','c19', 'c20', 'c21'] 
  
  # Calling DataFrame constructor on list 
  df = pd.DataFrame(lst) 
  
  Some list generator
  adds new list to cdf dataframe
  
  final df should be something like this not sure if i wrote this in the right syntax but a dataframe with 1 column haveing a list of 6 elements
  cdf = [[c1', 'c2', 'c3', 'c4','c5', 'c6'],['c7','c8', 'c9', 'c10', 'c11','c12'], ['c13', 'c14','c15', 'c16', 'c17', 'c18']...]
  </code></pre>
  
  <p>Thank you!</p>