Demonstrate operating syste dependent behaviour w.r.t static class members in subprocess

class-variable-in-subprocess.py

from multiprocessing import Process

class C(object):
    VAR = 'DEFAULT'


def print_c():
    print(f'C.VAR = {C.VAR}')

def main():
    print_c()
    C.VAR = 'CHANGED'
    print_c()

    p = Process(target=print_c, daemon=True)
    p.start()
    p.join()

if __name__ == "__main__":
  main()

Linux

$ uname -a
Linux puddle 4.14.134 #1-NixOS SMP Sun Jul 21 07:04:43 UTC 2019 x86_64 GNU/Linux

$ python --version
Python 3.6.9

$ python class-variable-in-subprocess.py
C.VAR = DEFAULT
C.VAR = CHANGED
C.VAR = CHANGED

Windows

H:\workspace>python --version
Python 3.6.5 :: Anaconda, Inc.

H:\workspace>python class-variable-in-subprocess.py
C.VAR = DEFAULT
C.VAR = CHANGED
C.VAR = DEFAULT