Source: 📖 Effective Python item 36

itertools.permutations

This function returns all the unique ordered permutations of the length prescribed by the second parameter:

it = itertools.permutations([1, 2, 3, 4], 2)
print(list(it))

>>>
[(1, 2),
 (1, 3),
 (1, 4),
 (2, 1),
 (2, 3),
 (2, 4),
 (3, 1),
 (3, 2),
 (3, 4),
 (4, 1),
 (4, 2),
 (4, 3)]