Appending to []

[Bernd Nawothnig]

On 2012-04-21, Kiuhnm wrote:
>> Returning a None-value is pretty useless. Why not returning self, which would be
>> the resulting list in this case? Returning self would make the
>> language a little bit more functional, without any drawback.
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>
>> Then nested calls like
>>
>> a = [].append('x').append('y').append('z')
>
> You just answered to your own question: append returns None so that 
> people can't use it the way you did.

That is one possible way to design the method, but not the only
possible way.

> You make the reader believe that you're adhering to the functional 
> paradigm whereas 'append' has actually side effects!
> Moreover, you use an assignment just to reinforce this wrong belief.

I know about side effects and I know that letting append return self
would not make Python a purely functional language with only immutable
data.

I just asked a simple question about a detail I personally would
consider it to be useful.

Please no further religious war about that ;-)




Bernd

-- 
"Die Antisemiten vergeben es den Juden nicht, dass die Juden Geist
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