--ini-enunciat
>>> import valors

>>> it1 = iter([2, 3, 3, 4, 6, 11, 9, 6])
>>> it2 = valors.transforma_seq(it1, 3)
>>> next(it2)
2
>>> next(it2)
3
>>> next(it2)
4
>>> for v in it2:
...    print(v, end=";")
6;8.5;11;9;6;
>>> it2 = valors.transforma_seq(iter([1, 2, 2, 2, 5, 6, 9, 2, 2, 10]), 2)
>>> for v in it2:
...    print(v, end=";")
1;2;3.5;5;6;7.5;9;5.5;2;6.0;10;

--fi-enunciat