Remove duplicate tuples from a list if they are exactly the same including order of items

set will take care of that:

>>> a = [(1,2,2), (2,2,1), (1,2,2), (4,3,5), (3,3,5), (3,3,5), (3,4,5)]
>>> set(a)
set([(1, 2, 2), (2, 2, 1), (3, 4, 5), (3, 3, 5), (4, 3, 5)])
>>> list(set(a))
[(1, 2, 2), (2, 2, 1), (3, 4, 5), (3, 3, 5), (4, 3, 5)]
>>>

set will remove only exact duplicates.

What you need is unique permutations rather than combinations:

y = list(set(itertools.permutations(x,3)))

That is, (1,2,2) and (2,1,2) will be considered as same combination and only one of them will be returned. They are, however, different permutations. Use set() to remove duplicates.

If afterwards you want to sort elements within each tuple and also have the whole list sorted, you can do:

y = [tuple(sorted(q)) for q in y]
y.sort()