reduce to be removed?

Steve Holden steve at holdenweb.com
Mon Nov 13 10:42:53 CET 2006


Paddy wrote:
> Dustan wrote:
> 
>> Anyway, I figured out a way to get the builtin
>> function 'sum' to work as I need:
>> sum([[1,2,3],[4,5,6],[7,8,9]],  [])
>>
> 
> Hah!
> No-one expects sum to be used on anything but numbers.
> 
> Except lists as above.
> 
> No-one expects sum to be used on anything but numbers, and maybe lists
> too.
> 
> ;-)
[voice mumbles:] "What about tuples"

Right, tuples too. But apart from tuples and lists, nobody expects sum 
to be used on anything but numbers.

In actual fact when Alex Martelli introduced sum() he intended it to be 
polymorphic over all the container types including strings. The check to 
exclude the string case was added when it was determined that it was 
terribly inefficient to concatenate strings that way. the same may well 
apply to other sequences.

I suppose it's only a matter of time before someone wants to define 
dict.__add__ ...

regards
  Steve
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