Let\'s assume I have the following DataFrame:
dic = {\'a\' : [1, 1, 2, 2, 2, 2, 3, 3, 3, 3], \'b\' : [1, 1, 1, 1, 2, 2, 1, 1, 2, 2], \'c\' : [\'f\', \'f\', \'f\'