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

[Nick Coghlan]

Guido van Rossum wrote:
>>I guess that leaves Alex's question of whether or not supplying a string of some
>>description as the initial value can be legitimately translated to:
>>
>>   if isinstance(initial, basestring):
>>     return initial + type(initial)().join(seq)
> 
> 
> If you're trying to get people in the habit of writing sum(x, "")
> instead of "".join(x), I fear that they'll try sum(x, " ") instead of
> " ".join(x), and be sadly disappointed.

That works for me as a reason not to provide this feature.

It's somewhat heartening when discussions like this turn out to show that the 
original design was right after all :)

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at email.com   |   Brisbane, Australia
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