Nick Craig-Wood <[EMAIL PROTECTED]> wrote: > Sion Arrowsmith <[EMAIL PROTECTED]> wrote: > > sum(...) > > sum(sequence, start=0) -> value > > > > If you're using sum() as a 1-level flatten you need to give it > > start=[]. > > Except if you are trying to sum arrays of strings... > > >>> sum(["a","b","c"], "") > Traceback (most recent call last): > File "<stdin>", line 1, in ? > TypeError: sum() can't sum strings [use ''.join(seq) instead] > >>> > > I've no idea why this limitation is here... perhaps it is because pre > python2.4 calling += on strings was very slow?
No: when I implemented sum, I originally specialcased sum on strings to map down to a ''.join -- Guido decided it was confusing and had no advantage wrt calling ''.join directly so he made me put in that check. Alex -- http://mail.python.org/mailman/listinfo/python-list
