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Date: Sun, 26 Aug 2012 23:58:31 +1000
Subject: Re: Objects in Python
From: Chris Angelico <rosuav@gmail.com>
To: python-list@python.org
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On Sun, Aug 26, 2012 at 11:43 PM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
> It gets worse: Python has multiple namespaces that are searched.
>
> "Go to the Excelsior Hotel and ask the concierge for Mr Smith. If Mr
> Smith isn't staying there, go across the road to the Windsor Hotel and
> ask there. If he's not there, try the Waldorf Astoria, and if he's not
> there, try the Hyperion."

Does it? I thought the difference between function-scope and
module-scope was compiled in, and everything else boils down to one of
those. Explicit dot notation is different ("ask for Mr Smith, then ask
him where his packages box is, and put this in the box").

Hmm, okay, there's something slightly different with closures. But
it's still unambiguous at compile time.

>>> x=1
>>> def foo(y):
	return lambda z: x+y+z

>>> foo(2)(3)
6
>>> import dis
>>> dis.dis(foo(2))
  2           0 LOAD_GLOBAL              0 (x)
              3 LOAD_DEREF               0 (y)
              6 BINARY_ADD
              7 LOAD_FAST                0 (z)
             10 BINARY_ADD
             11 RETURN_VALUE

What multiple namespaces are you talking about, where things have to
get looked up at run time?

ChrisA