checking if two things do not equal None

[Steven D'Aprano]

On Sat, 29 Mar 2014 17:07:20 -0400, Roy Smith wrote:

> I certainly agree that things like
> 
>> if a is not b is not None: ...
> 
> belong in an obfuscated coding contest. 

Apart from the fact that I got it wrong (that's what happens when I post 
at 6am after being up all night, thanks for the correction Lele), if you 
consider chained comparisons to be "obfuscated", I think you're not 
really fluent at Python. The OP even suggested  `a != None != b` so I 
think that (s)he at least understands chained comparisons.

However, I agree with Johannes that inverted conditions (using "not") are 
sometimes harder to reason about than "regular" conditions.



-- 
Steven D'Aprano
http://import-that.dreamwidth.org/