flatten a level one list
Nick Craig-Wood
nick at craig-wood.com
Thu Jan 12 10:30:04 EST 2006
Sion Arrowsmith <siona at chiark.greenend.org.uk> 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?
--
Nick Craig-Wood <nick at craig-wood.com> -- http://www.craig-wood.com/nick
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