call_stack.py

from contextlib import ExitStack
from functools import partial


# In some situation it's needed to care about program termination, explicitly or implicitly (by kill or raising an
# exception in the flow), situation likes send a notification on termination. For this purpose we can use contextlib
# of Python. Define our callbacks and put our main in an ExitStack. For more information see
# https://docs.python.org/3/library/contextlib.html#contextlib.ExitStack

def printStars():
    print("*********************************")


def someBuggyFunction():
    for i in range(5):
        print(i)

    raise Exception("Hello World")


with ExitStack() as stack:
    stack.callback(partial(printStars))

    someBuggyFunction()

    print("you never see this")

meysam@snappmarket:~/www/test/python/callstack 
$ python3 main.py 
0
1
2
3
4
*********************************
Traceback (most recent call last):
  File "main.py", line 24, in <module>
    someBuggyFunction()
  File "main.py", line 18, in someBuggyFunction
    raise Exception("Hello World")
Exception: Hello World

I really miss the defer of GO in python 😢.