Write by_last_letter(words) that sorts non-empty words by their last letter (ties keep their order).
by_last_letter(['sql', 'data', 'excel']) → ['data', 'sql', 'excel']
by_last_letter([]) → []
Submit runs 4 tests, including hidden edge cases.
Each hint gives a little more help. Try on your own first.
Run your code to see the output here.