How to number each print output?

If you just need to output it, use:

a = 987print(*str(a), sep=',')#                   /\\ Separator between elements#      /\\ Converting number to string#     /\\ Unpacking string into individual characters

If you need to save the string '9,8,7' somewhere, then:

a = 987result = ','.join(str(a))#                 /\\ Converting number to string#            /\\ Iterating over each character of the string#