Strange behavior when printing a returned closure function

[dartsch at dicad.de]

On Mar 25, 1:04 pm, Jean-Paul Calderone <exar... at divmod.com> wrote:
> On 25 Mar 2007 03:59:52 -0700, dart... at dicad.de wrote:
>
>
>
> >Hello,
>
> >when I execute the following code (python 2.5)
>
> >def f(x):
> >    def g():
> >        return x
> >    return g
>
> >print f(1)
> >print f(2)
>
> >I get an output like
>
> ><function g at 0x00AFC1F0>
> ><function g at 0x00AFC1F0>
>
> >So according to print I get the same function object returned at both
> >calls.
> >That's surprising, I would expect to get two distinct function objects
> >because their func_closure attribute has to be different. And indeed,
> >if I do
>
> >print f(1) is f(2)
>
> >instead, it prints False. Even more confusing, if I do
>
> >g1 = f(1)
> >g2 = f(2)
> >print g1
> >print g2
>
> >I get something like
>
> ><function g at 0x00AFC1B0>
> ><function g at 0x00AFC1F0>
>
> >ie. two distinct function objects are printed.
>
> >What's happening here?
> >Some clever optimization reusing function objects in special cases or
> >what ...?
>
> They're _not_ the same function object, just like the `is' test told you.
> They just happen to have been allocated at the same memory address.
>
> Jean-Paul

ah yes, I see, thanks