weird: "if x" and "if x is not None"

[Simon Brunning]

> From:	fortepianissimo at yahoo.com.tw [SMTP:fortepianissimo at yahoo.com.tw]
> I don't know what has changed, but the following code used to work
> fine now it doesn't:
> 
> result=d.get("key")
> if result:
>   # do something...
> 
> 
> the problem seems to be at "if result:" - before when result is not
> None, the if block will be executed. Now I have to literally say "if
> result is not None:" instead of that line.
> 
> My question is, what does the 'standard' say about this? (any non-None
> will make an 'if' test succeed?)
 
The if block will be executed for any *true* value. None is a false value,
as are zero values and empty strings, sequences and mappings. See
<http://www.python.org/doc/current/ref/Booleans.html> for the official word.

I would be *staggered* if this had changed...

Cheers,
Simon Brunning
TriSystems Ltd.
sbrunning at trisystems.co.uk




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