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Raymond Hettinger wrote:
> Raymond Hettinger <rhettinger@users.sourceforge.net> added the comment:
> 
> John, when y=[], the update method has to create a new list iterator on 
> each invocation.  But when y is a genexp, it is self-iterable (iow, iter
> (y) will return self, not a new object).
> 
> Also, when doing timings, it can be helpful to factor-out the attribute 
> lookup:
> 
> python -m timeit -s 'x=set(range(10000)); y=[]; xu=x.update' 'xu(y)'
> 
> __________________________________
> Tracker <report@bugs.python.org>
> <http://bugs.python.org/issue2672>
> __________________________________
> 

Sure, I wasn't surprised at the "set.update(y)" versus "set.update([])"

What I was surprised at is the time for:

"(i for i in [])" being about 4x longer than
"set.update(i for i in [])"

Anyway, the original issue is probably closed, whether we want to track
into the generator stuff or not is probably a different issue.

John
=:->

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