Question: 
Write a function to sort a list in increasing order by the last element in each tuple from a given list of non-empty tuples.


Model's Code:
def sort_list_last(tuples):
    return sorted(tuples, key=lambda x: x[-1])



Sample Correct Code:
def last(n):
   return n[-1]
def sort_list_last(tuples):
  return sorted(tuples, key=last)


Asserts:
assert sort_list_last([(2, 5), (1, 2), (4, 4), (2, 3), (2, 1)])==[(2, 1), (1, 2), (2, 3), (4, 4), (2, 5)] 
assert sort_list_last([(9,8), (4, 7), (3,5), (7,9), (1,2)])==[(1,2), (3,5), (4,7), (9,8), (7,9)] 
assert sort_list_last([(20,50), (10,20), (40,40)])==[(10,20),(40,40),(20,50)] 


Tests:
Test 1 of 3: PASS
Test 2 of 3: PASS
Test 3 of 3: PASS

Test 896 of 974: 690/896 (77.00892857142857%): success