如何等到用户关闭python中的进程？

Question

I want to create a program that init a new process and then wait until thhis process was killed by user or another program.

But i cant understand why the process create by subprocess is finished after a fraction of time and not by the user closing the process.

import subprocess
import psutil

old_process = {p.pid for p in psutil.process_iter()}
calc_process = subprocess.Popen('C:\Windows\System32\calc')
new_process = {p.pid for p in psutil.process_iter()}
process = list(new_process - old_process)[0]

while psutil.pid_exists(process):
    print('Process running')
print('Done')

Answer 1

Popen has this built in using the poll method.

from subprocess import Popen

process = Popen('C:\Windows\System32\calc')
process.wait()

while not process.poll():
    print('Process running')

print('Done')