[Python-Dev] Garbage collecting closures

[Jeremy Hylton]

On Mon, 2003-04-14 at 11:52, Phillip J. Eby wrote:
> If I understand correctly, it should also be breakable by deleting 'foo' 
> from the outer function when you're done with it.  E.g.:
> 
> def bar(a):
>       def foo():
>           return None
>           x = a
>           foo()
> 
>       del foo   # clears the cell and breaks the cycle
> 

You haven't tried this, have you? ;-)

SyntaxError: can not delete variable 'foo' referenced in nested scope

Since foo() could escape bar, i.e. become reachable outside of bar(), we
don't allow you to unbind foo.

Jeremy