* Steven D'Aprano:
On Sun, 28 Mar 2010 18:56:26 +0200, Alf P. Steinbach wrote:
From a more practical point of view, the sum efficiency could be
improved by doing the first addition using '+' and the rest using '+=',
without changing the behavior.
But that would change the behaviour. The __iadd__ method is not the same
as the __add__ method, and you can't guarantee that they will behave the
same -- or even similarly.
Hm, I don't think it's documented (except if the reference implementation serves
as documentation) which one is currently used.
And what about tuples? And subclasses of list/tuples? How many different
types need to be optimized?
Point. One would need to check for availability of '+='.
In practical terms, does anyone actually ever use sum on more than a
handful of lists? I don't believe this is more than a hypothetical
problem.
Agreed.
Cheers,
- Alf
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