Hi, is it possible to access the values stored on the stack in Python stack machine from Python?

As in, consider expression:

tmp = foo() + bar()

At the point in time when bar() is called, foo() already returned something, and that value is on top of the stack in that frame, a few steps after bar() returns, that value is added to bar and is lost.

I would very much like to be able to read (and maybe even change) that ephemeral value.

If it is absolutely not possible to achieve from Pythonland, I welcome pointers on how to write a C/cython/types extension to achieve this.