[Python-Dev] 2.5 and beyond

["Martin v. Löwis"]

skip at pobox.com wrote:
>     Ping> The question is, what behaviour is preferable for this code:
> 
>     Ping>     g = 1
>     Ping>     def f():
>     Ping>         g += 1
> 
>     Ping>     f()
> 
> If you treat "g += 1" as "g = g + 1" then it should create a local variable
> with a value of 2.

py> g = 1
py> def f():
...   g = g + 1
...
py> f()
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "<stdin>", line 2, in f
UnboundLocalError: local variable 'g' referenced before assignment

Regards,
Martin