当 python 进程被杀死时运行 atexit()

Question

I have a python process which runs in background, and I would like it to generate some output only when the script is terminated.

def handle_exit():
    print('\nAll files saved in ' + directory)
    generate_output()

atexit.register(handle_exit)

Calling raising a KeyboardInterupt exception and sys.exit() calls handle_exit() properly, but if I were to do kill {PID} from the terminal it terminates the script without calling handle_exit().

Is there a way to terminate the process that is running in the background, and still have it run handle_exit() before terminating?

Answer 1

Try signal.signal . It allows to catch any system signal:

import signal

def handle_exit():
    print('\nAll files saved in ' + directory)
    generate_output()

atexit.register(handle_exit)
signal.signal(signal.SIGTERM, handle_exit)
signal.signal(signal.SIGINT, handle_exit)

Now you can kill {pid} and handle_exit will be executed.

Answer 2

To enable signals when debugging PyCharm on Windows:

1. Within PyCharm hit Ctrl + Shift + A to bring up the "Find Actions..." menu
2. Search for "Registry" and hit enter
3. Find the key kill.windows.processes.softly and enable it (you can start typing "kill" and it will search for the key)
4. Restart PyCharm

Answer 3

To check your system and see which signal is being called:

import signal
import time


def handle_signal(sig_id, frame):
    sig = {x.value: x for x in signal.valid_signals()}.get(sig_id)
    print(f'{sig.name}, {sig_id=}, {frame=}')
    exit(-1)


for sig in signal.valid_signals():
    print(f'{sig.value}: signal.{sig.name},')
    signal.signal(sig, handle_signal)

time.sleep(30)