Appending to []

[Kiuhnm]

On 4/21/2012 18:14, Kiuhnm wrote:
> On 4/21/2012 17:41, Bernd Nawothnig wrote:
>> 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 ;-)
>
> Sorry if I wasn't clear. I meant that one should either relies on
> side-effects and write something like
> a.append('x').append('t').append('z')
> or use a more functional style and write
> a = a + [x] + [z]

Oops... I forgot the single quotes and the 't'.

Kiuhnm