[weakref]How to decide whether an object is alive in python?

[huangweiwu]

In the document: bound types no longer need to be weak-referenceable, which saves a pointer per instance.
But what if I want to whether an object is alive and do something in python?
If weakref is enabled, the code below is ok. The return value of loop_func can be used to terminate the loop in C++.
Is there anyway to enable the weak-refrence.

o = my_ext.MyObject()
weak_o = weakref.ref(o)
def loop_func():
    wo = weak_o()
    if not wo:
        return False
    return True
my_ext.loop(loop_func)

[wjakob]

There is an old (never merged PR due to some issues) by @hawkinsp (see #100) for enabling weak references. It's not on my priority list, so external help is welcome.

[huangweiwu]

The test works in CPython. Do you mean PyPy should be tested?
How to run it in PyPy environment.
In CPython, I build a my_ext.dll, rename it to my_ext.pyd and put it in the DLLs folder.

[wjakob]

How to do it on your own computer? I would say the normal way: download/install PyPy, build nanobind with it, etc.? And to be eligible for merigng, the whole test suite needs to pass on all platforms, as tested on GitHub CI.

[huangweiwu]

I'm willing to promote this work but I haven't used GitHub Cl before. And I'm not sure how to test it on all platforms.

[wjakob]

Sorry, I can't provide this level of support -- you'll have to learn how to use GitHub etc. yourself before contributing to this project.

[huangweiwu]

I've make a PR to support weakref, please check it if you have time?