Brian Harring wrote:
>
> I'd be curious if there is anyway to preserve the existing behaviour;
>
> class foo:
> some_list = ('blacklist1', 'blacklist2')
> known_bad = some_list += ('blah',)
> locals().update([(attr, some_callable) for attr in some_list])
>
> is slightly contrived, but I use similar code quite often for method
> generation- both for tests, and standard enough objects. Realize I
> could do the same via metaclasses, but it's an extra step and not
> nearly as easy/friendly imo.
>
> So... anyway to preserve that trick under py3k?
As you've written it, that trick isn't affected by the semantic change
at all (as the expression inside the list comprehension doesn't try to
refer to a class variable).
If 'some_callable' was actually a method of the class, then you'd need
to use an actual for loop instead of the list comprehension:
class foo(object):
some_list = ('blacklist1', 'blacklist2')
def some_method(self):
# whatever
pass
for attr in some_list:
locals()[attr] = some_method
However, I will point out that setting class attributes via locals() is
formally undefined (it happens to work in current versions of CPython,
but there's no guarantee that will always be the case).
Cheers,
Nick.
--
Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia
---------------------------------------------------------------
http://www.boredomandlaziness.org
_______________________________________________
Python-3000 mailing list
[email protected]
http://mail.python.org/mailman/listinfo/python-3000
Unsubscribe:
http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
