How to change the two columns at the same time?

Question

\'\'\' df = pd.DataFrame([[\'A\',\'B,B1\',\'C\',\'2,3,5\',\'F\',\'G\'], [\'h\',\'X,X1\',\'J\',\'2,4,8\',\'L\',\'M\'],[\'O\',\'P\',\'Q\',\'2,4\',\'S\',\'T\'], [\'