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 -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://holdenweb.blogspot.com Recent Ramblings http://del.icio.us/steve.holden -- http://mail.python.org/mailman/listinfo/python-list
