# digit_letters is defined as in the original def go(): import probstat # module for combinatorics valid_numbers = range(2,10) # 2..9 inclusive for (number_set) in probstat.Cartesian([valid_numbers]*4): answers = [] letter_sets = probstat.Cartesian([digit_letters[number] for number in number_set]) for (letter_set) in letter_sets: answers.append(''.join(letter_set)) # combine the four letters print number_set, ", ".join(answers)