[Python-Dev] PEP for Better Control of Nested Lexical Scopes (original) (raw)

Ron Adam rrr at ronadam.com
Tue Feb 21 16:48:21 CET 2006

Jeremy Hylton wrote:

On 2/21/06, Jeremy Hylton <jeremy at alum.mit.edu> wrote:

I had to lookup top-post :-).

On 2/21/06, Bengt Richter <bokr at oz.net> wrote: On Tue, 21 Feb 2006 08:02:08 -0500, "Jeremy Hylton" <jeremy at alum.mit.edu> wrote: Jeremy Hey, only Guido is allowed to top-post. He said so ;-) The Gmail UI makes it really easy to forget where the q Sorry about that. Hit the send key by mistake. The Gmail UI makes it really easy to forget where the quoted text is in relation to your own text. But to the topic, it just occurred to me that any outer scopes could be given names (including global namespace, but that would have the name global by default, so global.x would essentially mean what globals()['x'] means now, except it would be a name error if x didn't pre-exist when accessed via namespacename.nameinspace notation. Isn't this suggestion that same as Greg Ewing's? namespace galias # galias.x becomes alternate spelling of global.x def outer(): namespace mezzanine a = 123 print a # => 123 print mezzanine.a # => 123 (the name space name is visible and functional locally) def inner(): print mezzanine.a => 123 mezznine.a =456 inner() print a # = 456 global.x = re-binds global x, name error if not preexisting.

This would allow creating mezzanine like an attribute view of the slots in that local namespace, as well as making namespace itself visible there, so the access to mezzanine would look like a read access to an ordinary object named mezzanine that happened to have attribute slots matching outer's local name space.

Why not just use a class?

def incgen(start=0, inc=1) : class incrementer(object): a = start - inc def call(self): self.a += inc return self.a return incrementer()

a = incgen(7, 5) for n in range(10): print a(),

7 12 17 22 27 32 37 42 47 52

Cheers, Ronald Adam

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