Using 'apply' as a decorator, to define constants

[Jonathan Fine]

alex23 wrote:

> Unfortunately, apply() has been removed as a built-in in 3.x. I'm not
> sure if it has been relocated to a module somewhere, there's no
> mention of such in the docs.

The old use of apply()

> You can save yourself the tidy up by using the same name for the
> function & the label:
> 
>     def tags():
>         value = []
>         # ...
>         return value
>     tags = tags()

I don't like that because there's no hint at
     def tags():
that this is /not/ the value of tags.

>> Like all uses of decorators, it is simply syntactic sugar.  It allows
>> you to see, up front, what is going to happen.  I think, once I get used
>> to it, I'll get to like it.
> 
> The question is, is it really that useful, or is it just a slight
> aesthetic variation? Given that apply(f, args, kwargs) is identical to
> f(*args, **kwargs), it's understandable that's apply() isn't seen as
> worth keeping in the language.

Yes, I agree with that, completely.

> Why I've personally stopped using it: I've always had the impression
> that decorators were intended to provide a convenient and obvious way
> of augmenting functions. 

Yes, that was the intended use case.

> Having one that automatically executes the
> function at definition just runs counter to the behaviour I expect
> from a decorator. 

I'd expect the name of the decorator to explain what is going on.  If 
apply() were a well known part of the language, that would be fine.

> Especially when direct assignment... foo = foo
> () ...is a far more direct and clear way of expressing exactly what is
> happening.

Actually, I think the decorator approach is clearer.  But that's just my 
opinion, and not with the benefit of a lot of experience.

> But that's all IMO, if you feel it makes your code cleaner and don't
> plan on moving to 3.x any time soon (come on in! the water's great!),
> go for it :)

Thank you for your comments, Alex.  And particularly for telling me that 
apply() is no longer a builtin for Python 3.

-- 
Jonathan