global variable not seen (bug?)
Mike Meyer
mwm at mired.org
Wed Jan 8 12:14:36 EST 2003
Michal Vitecek <fuf at mageo.cz> writes:
> hello everyone,
>
> i've encountered a strange problem with accessing a global variable
> from imported module. the imported module (file imported.py) contains:
>
> ---imported.py start---
> def someFunction():
> global GLOBAL_VARIABLE
>
> print GLOBAL_VARIABLE
> ---imported.py end---
>
> and now the session copy:
>
> ---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().
<mike
--
Mike Meyer <mwm at mired.org> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.
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