Usefulness of the "not in" operator

[Steven D'Aprano]

candide wrote:

> Le 08/10/2011 14:01, Steven D'Aprano a écrit :
> 
>  > And "not in" is the obvious way to do it.
> 
> Obvious ? Not so. I performed some code mining and it appears that even
> good sources make use of  "not (foo in bar)" expressions.

All that proves is that even expert Python developers can, on occasion,
write non-idiomatic Python -- or that they accept code contributed by
non-expert Python developers, and don't bother adjusting trivial stylistic
flaws.

When I learned Pascal 20+ years ago, it took me a long time to stop
writing "x not in y" and learn the non-English-like "not x in y". Then I
learned Python, and it took me a while to stop writing Pascal code in
Python. Bad habits take a while to disappear.

(I never added superfluous semi-colons after each line though!)



-- 
Steven