[Python-Dev] Single- vs. Multi-pass iterability

[Guido van Rossum]

> I don't know if we need them, but I'm certainly finding that not having
> some more information is difficult for me. If I need to make multiple
> passes over the information in a generalized iterable object, the only
> solution AFAICT is to unconditionally copy all the information into a list
> first.

Or you could just document "this argument must support multiple
independent iterators."

--Guido van Rossum (home page: http://www.python.org/~guido/)