For the issue #22599, I wrote a patch but then I removed my patch and reverted my changed...

Here is a new patch which implements why I already wrote: add a new sys._is_finalizing() function, with a unit test.

> I propose to add a new function sys.shutting_down() (name debatable)

The name sounds like a function to shut down the computer or exit Python.

I don't like _is_finalizing() name neither :-)

My patch uses a private function which is CPython specific. Does it make sense to add a public function instead? Is it possible to implement it in any Python implementation (PyPy, IronPython, Jython, etC.)? I guess that the most dummy implementation is to always return False (Python is always running.