How to write this iterator?

[severa at sophia.dtp.fmph.uniba.sk]

>> Sorry, my description was not very good, I meant something behaving as:
>>
>> >>>example=Liter("abc","12345","XY")
>> >>>for x in example: print x,
>>
>> a 1 X b 2 Y c 3 4 5
>>
>> or for that append() method,
>>
>> >>>example=Liter("abc", "12345")
>> >>>for i in range(3): print example.next(),
>>
>> a 1 b
>>
>> >>>example.append("XY")
>> >>>for x in example: print x,
>>
>> 2 c X 3 Y 4 5

>Check the module I posted on
>http://rafb.net/paste/results/CRT7bS68.html. append() makes things more
>complicated -- mainly because generators don't accept attributes, so it
>has to be wrapped in a class -- but the simple generator (without
>append) is more manageable

Thank you very much for your solution. Actually I needed that append() 
method quite a lot, so maybe my solution (posted at the beginning of this 
thread) was not that stupid :) (to inflate my ego a bit)

Anyway, this is roughly what I used it for; is it a sane use of iterators?

I was looking for the Holy Grail. I had an iterator 'quest' that produced 
either junk that was to be thrown away, or the Holy Grail itself, or 
another iterator of the same kind (that had to be searched for the Holy 
Grail as well). The iterators were potentially infinite. The code was 
rougly:

quest=Liter(quest)    
for x in quest:
    if is_Holy_Grail(x):
        share_and_enjoy(x)
        break
    elif is_another_iterator(x):
        quest.append(x) 


Best regards
P.