[Python-Dev] odd "tuple does not support assignment" confusion...

Sat Mar 3 07:51:21 CET 2012

I knew this was a feature!!!
....features such as these should be fixed! %)
On Sat, Mar 3, 2012 at 03:38, R. David Murray <rdmurray at bitdance.com> wrote:
> On 2012年3月03日 03:06:33 +0400, "Alex A. Naanou" <alex.nanou at gmail.com> wrote:
>> Hi everyone,
>>>> Just stumbled on a fun little thing:
>>>> We create a simple structure...
>>>>   l = ([],)
>>>>>> Now modify the list, and...
>>>>   l[0] += [1]
>>>>>> ...we fail:
>> ## Traceback (most recent call last):
>> ##   File "F:\work\ImageGrid\cur\ImageGrid\src\test\python-bug.py",
>> line 17, in <module>
>> ##     l[0] += [1]
>> ## TypeError: 'tuple' object does not support item assignment
>> What is even more fun is that the append actually worked (try printing
> l).
>> This is not a bug, it is a quirk of how extended assignment works.
> I think there's an issue report in the tracker somewhere that
> discusses it.
>> --David

-- 
Alex.