for-loop - Python 3: find previous/next element in for loop

Question

This question has been answered before for Python 2.x. I can not get it to work in Python 3.

I changed izip to zip, because I understood izip was removed from Python 3.

from itertools import tee, islice, chain

def previous_and_next(some_iterable):
    prevs, items, nexts = tee(some_iterable, 3)
    prevs = chain([None], prevs)
    nexts = chain(islice(nexts, 1, None), [None])
    print(zip(prevs, items, nexts))

a = list(range(1,10))

previous_and_next(a)

Running this gives me <zip object at 0x7f338e4ea638>

What is wrong with this code?