context manager to block signals

signalblocker.py

import time
import signal


class SignalBlocker:

    def __init__(self, signal):
        self._signal = signal
        self._signal_blocked = False

    def _handler(self, signum, frame):
        self._signal_blocked = True

    def __enter__(self):
        self._original_handler = signal.getsignal(self._signal)
        signal.signal(self._signal, self._handler)

    def __exit__(self, exc_type, exc_val, exc_tb):
        signal.signal(self._signal, self._original_handler)
        if self._signal_blocked:
            raise Exception("Ctrl-C received")


if __name__ == "__main__":
    with SignalBlocker(signal.SIGINT):
        for i in range(5):
            time.sleep(1)
            print("critical section")
    print("outside section")