[Python-3000] replace globals() and global statement with global builtin object

[Steven Bethard]

On 6/30/06, Guido van Rossum <guido at python.org> wrote:
> On 6/30/06, Steven Bethard <steven.bethard at gmail.com> wrote:
> > On 6/30/06, Guido van Rossum <guido at python.org> wrote:
> > > On 6/30/06, Steven Bethard <steven.bethard at gmail.com> wrote:
> > > > BJörn Lindqvist wrote:
> > > > > I have often wanted something similar to that for global
> > > > > variables, instead of the global declaration:
> > > > >
> > > > > cache = None
> > > > > def init():
> > > > >     if not global.cache:
> > > > >         global.cache = init_cache()
> > > >
> > > > Redirected since this seemed like a Python 3000 kind of request.  I
> > > > like the idea, particularly because it coincides well with my usual
> > > > uses for global/globals().  Seems like it might require some changes
> > > > in things like eval and exec that take locals and globals dicts, but I
> > > > don't know how much of a drawback that is.
> > >
> > > You realize that *reading* a global doesn't need the "global." prefix,
> > > do you? So you could have written "if not cache: global.cache =
> > > init_cache()" in the function body.
> >
> > That's also true for the global statement, right?  That is, the ``if
> > not cache`` part would not need a global statement, whlie the ``cache
> > = init_cache()`` part would.
> >
> > That said, I agree it does nothing to solve the asymmetry.
>
> At least with the global statement, the notation for the variable
> reference remains the same. E.g. you can write
>
>   x = f(x)
>
> and everybody will understand that the x on the left and right refer
> to the same variable.
>
> You'd lose that with
>
>   globals.x = f(x)
>
> IMO that's enough of a drawback to give it a solid -1.

Sounds reasonable. Should I update PEP 3099?  Something like this
comes up every few months.

Oh, also, is the -1 only to replacing the global keyword?  Or is it
also to the idea of replacing globals() with a builtin
pseudo-namespace object like the one above?

STeVe
-- 
I'm not *in*-sane. Indeed, I am so far *out* of sane that you appear a
tiny blip on the distant coast of sanity.
        --- Bucky Katt, Get Fuzzy