A Bug By Any Other Name ...

[Gabriel Genellina]

En Mon, 06 Jul 2009 00:28:43 -0300, Steven D'Aprano  
<steve at remove-this-cybersource.com.au> escribió:
> On Mon, 06 Jul 2009 14:32:46 +1200, Lawrence D'Oliveiro wrote:
>
>> I wonder how many people have been tripped up by the fact that
>>
>>     ++n
>>
>> and
>>
>>     --n
>>
>> fail silently for numeric-valued n.
>
> What do you mean, "fail silently"? They do exactly what you should  
> expect:
>>>> ++5  # positive of a positive number is positive
>
> I'm not sure what "bug" you're seeing. Perhaps it's your expectations
> that are buggy, not Python.

Well, those expectations are taken seriously when new features are  
introduced into the language - and sometimes the feature is dismissed just  
because it would be confusing for some.
If a += 1 works, expecting ++a to have the same meaning is very reasonable  
(for those coming from languages with a ++ operator, like C or Java) -  
more when ++a is a perfectly valid expression.
If this issue isn't listed under the various "Python gotchas" articles, it  
should...

-- 
Gabriel Genellina