[obiterdictum]

I think that dependency on argument evaluation order inside zip function smells a bit.

It's OK here, but may bite you with a different function.

[cbr]

    The left-to-right evaluation order of the
    iterables is guaranteed.

http://docs.python.org/2/library/functions.html#zip

[weavejester]

Yes, but only for zip, which I believe was the parent posters point. With another function this technique might not work.