Boolean value of generators

[Paul Rubin]

Carl Banks <pavlovevidence at gmail.com> writes:
> In general, the only way to test if a generator is empty is to try to
> consume an item.  (It's possible to write an iterator that consumes an
> item and caches it to be returned on the next next(), and whose
> boolean status indicates if there's an item left. ...)

I remember thinking that Python would be better off if all generators
automatically cached an item, so you could test for emptiness, look
ahead at the next item without consuming it, etc.  This might have been
a good change to make in Python 3.0 (it would have broken compatibility
with 2.x) but it's too late now.