[Python-ideas] [Python-Dev] Scope object (Re: nonlocals() function?)

[Greg Ewing]

Antoine Pitrou wrote:

> It is useful to distinguish between globals (i.e., module-level variables) and
> locals, so replacing them with scope() would not be better IMO.

You have a point about globals(), so it probably makes
sense for it to stay.

I still think that it wouldn't hurt to subsume locals()
and the proposed nonlocals() into a single function
returning some kind of view object, though. But I
suppose we'd have to examine use cases before deciding
that.

The main use case I can think of is things like

   print "Your %(vehicle)s is full of %(fish)s" % locals()

where I can't see a good reason for restricting the
lookup to locals but not nonlocals, or even globals.

> If you can prove that making locals() (or its replacement) writable doesn't
> complicate the interpreter core too much, then why not. Otherwise -1 :-)

It shouldn't be hard to support changing the values
of *existing* names, which all that I really meant.
I wouldn't expect to be able to create new local
names through it.

-- 
Greg