[Python-ideas] sum(...) limitation

[Antoine Pitrou]

Le 13/08/2014 12:37, Steven D'Aprano a écrit :
>
> sum() is *not* the One Obvious Way to add arbitrary objects in every
> domain.

Well, it is. It's a builtin and it's called "sum", which makes it pretty 
clear it adds objects together. That could hardly be any more obvious, 
actually: all competitors are *less* obvious.

Indeed it cannot *practically* be the most efficient or accurate to sum 
arbitrary objects, unless we manage to devise a clever protocol 
(__sum__? how would that work?) that can delegate to arbitrary 
third-party code. But people are bound to think, legitimately, that 
built-in sum() is the logical answer when wanting to sum a sequence of 
objects.

(of course, whether or not "sum" is a reasonable notion when applied to 
strings - rather than lists or floats - is a separate question)

Regards

Antoine.