sum and strings

[Carl Banks]

Steven D'Aprano wrote:
>But I think it is a shame that sum() does a
> special type-check to avoid something which is only sometimes slow. It
> doesn't protect against O(n**2) performance; it merely protects against
> just one of an infinite number of possible "traps for the unwary".

I'm not so sure special casing was a good idea myself, but...

If you allow for a small number of special cases in the language to
protect against the most harmful and prone traps, this case would be
one of the top ones, IMHO.


Carl Banks


and, you know, if you really want to concatenate strings with sum, you
can

class noopadd(object):
    def __add__(self,other):
        return other

sum(["abc","def","ghi"],noopadd())