[PyQt] Sip iterator question

[Giovanni Bajo]

On 8/31/2009 4:24 PM, Sébastien Petitdemange wrote:
> David Boddie wrote:
>> On Mon, 24 Aug 2009 13:08:44 +0200, Sebastien Petitdemange wrote:
>>
>>> Sébastien Petitdemange wrote:
>>>> I try to create an iterator using python iterator protocol but I didn't
>>>> succeed.
>> [...]
>>
>>>> Data_HeaderContainer_itemIterator* __iter__();
>>>> %MethodCode
>>>> sipRes = sipCpp;
>>>> %End
>>>> };
>>>>
>>>> and we I use it in python, It say that my object is not an iterator :
>>>>
>>>> for k in i:
>>>> ...     print k
>>>> ...
>>>> Traceback (most recent call last):
>>>>   File "<stdin>", line 1, in <module>
>>>> TypeError: 'Data_HeaderContainer_itemIterator' object is not iterable
>>>>
>>>> what I'm I missing?
>> Maybe the value returned by __iter__() isn't what the interpreter is
>> expecting. Having said that, I think it's possible that the type structure
>> information created by SIP doesn't have the necessary fields filled in to
>> allow the object to be used to create an iterator, even if you define
>> __iter__() for this purpose.
>>
>> Has anyone else encountered this problem, perhaps with tools other than SIP?
>>
>> David
>>
> As a conclusion, to create an iterator in C for python, you have to
> define tp_iter slot and it seems that SIP don't yet recognize __iter__
> as a slot that why it doesn't work.
> 
> Hope this feature will be add to SIP!
> 
> Thanks for your replay.

Remember that many containers are already iterable just because they 
support operator[] (aka __getitem__). So if you have a container, it's 
sufficient to expose __getitem__ (which is probably a good idea anyway) 
to make it iterable.
-- 
Giovanni Bajo
Develer S.r.l.
http://www.develer.com