max(), sum(), next()
steve at REMOVE-THIS-cybersource.com.au
Thu Sep 4 03:30:14 CEST 2008
On Wed, 03 Sep 2008 16:20:39 -0700, Mensanator wrote:
> is a bug, just as it's a bug in Excel to evaluate blank cells as 0. It
> should return None or throw an exception like sum([None,1]) does.
You're wrong, because 99.9% of the time when users leave a blank cell in
Excel, they want it to be treated as zero. Spreadsheet sum() is not the
same as mathematician's sum, which doesn't have a concept of "blank
cells". (But if it did, it would treat them as zero, since that's the
only useful thing and mathematicians are just as much pragmatists as
spreadsheet users.) The Excel code does the right thing, and your "pure"
solution would do the unwanted and unexpected thing and is therefore
Bugs are defined by "does the code do what the user wants it to do?", not
"is it mathematically pure?". The current behaviour of sum() does the
right thing for the 99% of the time when users expect an integer. And the
rest of the time, they have to specify a starting value for the sum
anyway, and so sum(, initial_value) does the right thing *always*.
The only time it does the wrong thing is when you forget to pass an
initial value but expect a non-numeric result. And that's the
programmer's error, not a function bug.
 I believe it also does the wrong thing by refusing to sum strings,
but that's another story.
More information about the Python-list