selfish = '01234567'
          #01234567

selfish[start:stop:stepover]

# immutability = cannot be changed
# now that we've assigned selfish, remember that strings are immutable

# NO NO NO
# selfish[0] '8' => this cannot be done

# How can we change it?
# we must ressign it entirely. 
# TLDR; we can't reassign a part of a string


