Python vs Java garbage collection?

["Martin v. Löwis"]

A. Lloyd Flanagan wrote:
> The difference between C++
> destructors and Java's finalize() or Python's __del__() is that C++
> _guarantees_ that the destructor will get called sometime before the
> program exits (barring a core dump or other catastrophe). 

In general, C++ makes no such guarantee. If I do

Foo *foo = new Foo;

and never mention foo in a delete statement, the Foo destructor won't be 
  called.

> From the Python reference manual: "It is not guaranteed that __del__()
> methods are called for objects that still exist when the interpreter
> exits."

The same is true for destructors in C++.

> So I think what he's saying is that he wants a guarantee that
> __del__() gets called at some point, and I agree with him.

I think he means something different. If there was just a guarantee that 
the destructor is called at some point, I believe he would not be 
satisfied. Unfortunately, I still can't infer from that what it would 
mean to integrate destructors into Python.

Regards,
Martin