intricated functions: how to share a variable

Chris Rebert clp2 at rebertia.com
Wed Aug 5 12:42:23 CEST 2009


On Wed, Aug 5, 2009 at 3:13 AM, TP<Tribulations at paralleles.invalid> wrote:
> Hi everybody,
>
> See the following example:
>
> #########
> def tutu():
>
>    def toto():
>

    nonlocal a #note: this requires a rather recent version of python

>        print a
>        a = 4
>        print a
>
>    a=2
>    toto()
>
> tutu()
> ##########
>
> I obtain the following error:
> "UnboundLocalError: local variable 'a' referenced before assignment"
>
> This is because Python looks in the local context before looking in the
> global context.
>
> The use of "global a" in toto() does not help because global allows to force
> Python to look for the variable at the module level.
>
> So, how to share a variable between intricated functions?

Details: http://www.python.org/dev/peps/pep-3104/

Cheers,
Chris
-- 
http://blog.rebertia.com



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