[Tutor] diferent between " "(empty string) and None as condition

[boB Stepp]

On Fri, Apr 24, 2020 at 7:56 AM Mats Wichmann <mats at wichmann.us> wrote:

> === extra credit, no need to go here if you don't want:
>
> There are also cases where things are coded in such a way that None is a
> valid value, and can't be used as the sentinel, and you need yet another
> value to distinguish that something out-of-band happened...

Would you please show a realistic example where one might do this --
where None can't be used as a sentinel because it is otherwise
occupied?


-- 
boB