global variable not seen (bug?)

[Cliff Wells]

On Wed, 2003-01-08 at 09:03, Skip Montanaro wrote:
>     Michal> ---imported.py start---
>     Michal>  def someFunction():
>     Michal>     global GLOBAL_VARIABLE
> 
>     Michal>     print GLOBAL_VARIABLE
>     Michal> ---imported.py end---
> 
> Somebody still has to actually assign a value to that name.  All the global
> declaration does is tell the system that if you assign a value to the
> variable to put it in the global scope of the module, not the local scope
> (the function).  This would work:
> 
>     GLOBAL_VARIABLE = None
>     def someFunction():
>         print GLOBAL_VARIABLE

If you read the OP's entire post (particularly the cut&paste from the
interactive Python session) you'll see that he in fact did assign to
GLOBAL_VARIABLE.  It just wasn't in the module that actually used it.
The problem is that "globals" aren't really.  They are global only to
the module they were defined in.

To the OP: please don't use globals like this, even in languages that
allow it.  Modules that depend upon a global variable being defined in a
different module are not modulular.  Besides, anyone working on the code
later will hate you and make disparaging comments about your competence
in the source.  Further, it'll be deserved.


Globals-bite-large-chunks-of-ass'ly yrs,

-- 
Cliff Wells, Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 x308  (800) 735-0555 x308