None versus MISSING sentinel -- request for design feedback

[Steven D'Aprano]

Chris Angelico wrote:

> On Fri, Jul 15, 2011 at 8:46 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
>> In general, you have missing values in statistics because somebody
>> wouldn't answer a question, and the Ethics Committee frowns on
>> researchers torturing their subjects to get information. They make you
>> fill out forms.
>>
> 
> Which, then, is in support of an explicit "User chose not to answer
> this question" MISSING value.

Well yes, but None is an explicit missing value too. The question I have is
if I should support None as that value, or something else. Or if anyone can
put a good case for it, both, or neither and so something completely
different.



-- 
Steven