[Python-Dev] Rationale for sum()'s design?

[Gareth McCaughan]

On Tuesday 2005-03-15 01:57, Guido van Rossum wrote:
> I think the conclusion should be that sum() is sufficiently
> constrained by backwards compatibility to make "fixing" it impossible
> before 3.0. But in 3.0 I'd like to fix it so that the 2nd argument is
> only used for empty lists.

Why's that better than having the 2nd argument only *needed*
for empty lists, but *used* whenever it's given?

-- 
g