examples/lists/sort.py
from __future__ import print_function

letters = ['a', 'x', 'b', 'z']
print(letters)         # ['a', 'x', 'b', 'z']
letters.sort()
print(letters)         # ['a', 'b', 'x', 'z']

letters.sort(reverse=True)
print(letters)         # ['z', 'x', 'b', 'a']