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Re: Question about name scope

References <20120201181117.5d35dddc@bigfoot.com> <mailman.5311.1328117874.27778.python-list@python.org> <jgc1cr$976$1@speranza.aioe.org> <CALwzidmBvCmeMOiSjOscuiTx7VXVmMvWkBU7hwQW5JDV85+N4A@mail.gmail.com> <4F29BB9C.70405@stoneleaf.us>
From Ian Kelly <ian.g.kelly@gmail.com>
Date 2012-02-01 15:38 -0700
Subject Re: Question about name scope
Newsgroups comp.lang.python
Message-ID <mailman.5327.1328135930.27778.python-list@python.org> (permalink)

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On Wed, Feb 1, 2012 at 3:24 PM, Ethan Furman <ethan@stoneleaf.us> wrote:
> Definitely should rely on it, because in CPython 3 exec does not un-optimize
> the function and assigning to locals() will not actually change the
> functions variables.

Well, the former is not surprising, since exec was changed from a
statement to a built-in.  I don't see any difference in the way
locals() behaves, though:

Python 3.2 (r32:88445, Feb 20 2011, 21:29:02) [MSC v.1500 32 bit (Intel)] on win
32
Type "help", "copyright", "credits" or "license" for more information.
>>> def f(x, y):
...     locals()[x] = y
...     print(vars())
...     exec('print(' + x + ')')
...
>>> f('a', 42)
{'y': 42, 'x': 'a', 'a': 42}
42

That still seems to work as I described it.  You couldn't directly
reference it as 'a', though, since the result would be either that it
would try to look up a global with that name, or the compiler would
consider it a local, optimize it, and then you could no longer assign
it via locals().

Cheers,
Ian

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Thread

Question about name scope Olive <diolu@bigfoot.com> - 2012-02-01 18:11 +0100
  Re: Question about name scope Rick Johnson <rantingrickjohnson@gmail.com> - 2012-02-01 09:21 -0800
  Re: Question about name scope Ethan Furman <ethan@stoneleaf.us> - 2012-02-01 09:43 -0800
  Re: Question about name scope Dave Angel <d@davea.name> - 2012-02-01 12:36 -0500
    Re: Question about name scope Mel Wilson <mwilson@the-wire.com> - 2012-02-01 13:47 -0500
      Re: Question about name scope Ian Kelly <ian.g.kelly@gmail.com> - 2012-02-01 14:49 -0700
      Re: Question about name scope Ian Kelly <ian.g.kelly@gmail.com> - 2012-02-01 15:38 -0700
      Re: Question about name scope Ethan Furman <ethan@stoneleaf.us> - 2012-02-01 14:24 -0800
      Re: Question about name scope Ian Kelly <ian.g.kelly@gmail.com> - 2012-02-01 16:00 -0700
      Re: Question about name scope Ethan Furman <ethan@stoneleaf.us> - 2012-02-01 15:08 -0800
      Re: Question about name scope Ian Kelly <ian.g.kelly@gmail.com> - 2012-02-01 16:47 -0700
      Re: Question about name scope Ethan Furman <ethan@stoneleaf.us> - 2012-02-01 14:53 -0800
        Re: Question about name scope Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-02-02 00:34 +0000
      Re: Question about name scope Ethan Furman <ethan@stoneleaf.us> - 2012-02-01 15:59 -0800
      Re: Question about name scope Ethan Furman <ethan@stoneleaf.us> - 2012-02-01 15:41 -0800
      Re: Question about name scope Ethan Furman <ethan@stoneleaf.us> - 2012-02-01 15:51 -0800
  Re: Question about name scope Chris Rebert <clp2@rebertia.com> - 2012-02-01 09:38 -0800
  Re: Question about name scope Christian Heimes <lists@cheimes.de> - 2012-02-01 18:50 +0100

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