more fun with iterators (mux, demux)

Raymond Hettinger python at
Wed Apr 8 23:58:12 CEST 2009

> I assume that "smallish values of n" refers to the fact that
> itertools.tee places items into every generator's internal deque,
> which islice then skips over, whereas your version places items only
> into the deque of the generator that needs it.

The pure python equivalent listed in the docs uses separate
deques for each subiterator, but the actual C implementation
of itertools.tee() only has one internal deque that is shared
by all of the sub-iterators.


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