deques in python3

1def moving_average(iterable, n=3):
2    # moving_average([40, 30, 50, 46, 39, 44]) --> 40.0 42.0 45.0 43.0
3    # http://en.wikipedia.org/wiki/Moving_average
4    it = iter(iterable)
5    d = deque(itertools.islice(it, n-1))
6    d.appendleft(0)
7    s = sum(d)
8    for elem in it:
9        s += elem - d.popleft()
10        d.append(elem)
11        yield s / float(n)
12