It should be noted that the Python language spec explicitly says that refcounting, and the resulting deterministic cleanup, is an implementation detail of CPython, and not part of the Python language proper. Precisely so that other implementations like Jython or IronPython could just use GC without refcounting.

https://docs.python.org/3/reference/datamodel.html#objects-v...

So, idiomatic Python does not rely on this, and uses with-statements for deterministic cleanup.

But, of course, as with any language, there's plenty of non-idiomatic Python out in the wild.