[Pandas-dev] [pydata] Feedback request for return value of empty or all-NA sum (0 or NA?)

[Pietro Battiston]

Il giorno ven, 08/12/2017 alle 12.19 +0000, Jeff Reback via Pandas-dev
ha scritto:
> [...]
> Changing this behavior shakes the core tenants of pandas, suddenly we
> have a special case
> where NaN propagation is not important anymore and worse you may get
> wrong answers.

Having to do with tons of NaNs every day, I understand your concerns,
but I see only one solution to your problems, "skipna=False".


> I would argue that the folks who want guaranteed zero for all-NaN,
> can simply fill first. The reverse operation is simply
> not possible, nor desired in any actual real world scenario.

Isn't it skipna=False?!

> 
> Pandas is not about strictly mathematical purity, rather about real
> world utility. 

Sure utility matters, but I think consistency helps avoiding surprises,
which is very useful, in particular in the middle of a huge API.

Pietro