Zip on single element in nested sequence.

[ichabod801]

With Toolz a little nicer.

It appears they are just using islice:

next(itertools.islice(seq, n, None))

[nilamo]

Yeah, that would work for n=2, but it doesn't seem super elegant to me. I wish there was something in itertools to get the nth item of an iterator.

Seems easy enough to make, though:

>>> def nth(ndx, collection):
...   last = None
...   for _ in range(0, ndx+1):
...     last = next(collection)
...   return last
...
>>> a = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
>>> nth(1, zip(*a))
(2, 5, 8)

Or if you prefer comprehensions:

>>> def nth(ndx, collection):
...   vals = [next(collection) for _ in range(0, ndx+1)]
...   return vals[-1]
...
>>> a = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
>>> nth(1, zip(*a))
(2, 5, 8)

[micseydel]

A regular loop and islice both work but the comprehension will use memory proportional to the index you want, rather than a fixed amount.

[nilamo]

Either way, I think a loop is about the best you can get and still be generic enough to work with things like generators that emit streams of data from sockets, since you can't exactly skip ahead for that.

[micseydel]

I would prefer islice over a loop. It might be smart enough at some point to be able to negotiate "skipping ahead" in a generator in the future but I feel like a loop will never be.