global variable not seen (bug?)

Peter Hansen peter at engcorp.com
Wed Jan 8 18:24:07 CET 2003


Mike Meyer wrote:
> 
> Michal Vitecek <fuf at mageo.cz> writes:
> > ---session start---
> > Python 2.2.1 (#4, Sep  4 2002, 13:43:54)
> > [GCC 2.95.3 20010315 (release)] on linux2
> > Type "help", "copyright", "credits" or "license" for more information.
> > >>> GLOBAL_VARIABLE = 'some value'
> > >>> from imported import *
> > >>> dir()
> > ['GLOBAL_VARIABLE', '__builtins__', '__doc__', '__name__', 'someFunction']
> > >>> someFunction()
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in ?
> >   File "imported.py", line 4, in someFunction
> >     print GLOBAL_VARIABLE
> > NameError: global name 'GLOBAL_VARIABLE' is not defined
> > >>>
> > ---session end---
> >
> >  what's the problem here? it seems to me like this is a bug in python.
> 
> The global statement doesn't declare a variable, it tells the
> interpreter to look in the global namespace for the variable. Since it
> isn't there, the name is going to be undefined. Try doing
> "GLOBAL_VARIABLE = 1" in your interpreter before you infoke
> someFunction().

If you look closely, you'll see he did a "GLOBAL_VARIABLE = 'some value'"
in the interpreter before invoking someFunction(), which should have
worked if your explanation is valid.

-Peter




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