[Python-Dev] Showstopper in import?

[M.-A. Lemburg]

Jeremy Hylton wrote:
> 
>   MAL> Better issue a warning than raise an exception here !
> 
>   TP> If Jeremy can't generate correct code, a warning is too weak.
> 
>   MAL> So this is the price we pay for having nested scopes... :-(
> 
>   TP> I don't know.  It apparently is the state of the code at this
>   TP> instant.
> 
> The code is complaining about 'from ... import *' with nested scopes,
> because of a potential ambiguity:
> 
> def f():
>     from string import *
>     def g(s):
>         return strip(s)
> 
> It is unclear whether this code intends to use a global named strip or
> to the name strip defined in f() by 'from string import *'.

The right thing to do in this situation is for Python to walk
up the nested scopes and look for the "strip" symbol.
 
> It is possible, I'm sure, to complain about only those cases where
> free variables exist in a nested scope and 'from ... import *' is
> used.  I don't know if I will be able to modify the compiler so it
> complains about *only* these cases in time for 2.1a2.

Since this is backward compatible, wouldn't it suffice to
simply use LOAD_GLOBAL for all nested scopes below the first
scope which uses from ... import * ?

-- 
Marc-Andre Lemburg
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