python signal timeout

signal_timeout.py

# encoding=utf8
import signal
import time


class TimeoutError(Exception):
    pass


class Timeout(object):
    def __init__(self, seconds):
        self.seconds = seconds
        self._default = None

    def _add_signal(self):
        def handler(error, frame):
            raise TimeoutError

        self._default = signal.getsignal(signal.SIGALRM)
        signal.signal(signal.SIGALRM, handler)
        signal.alarm(self.seconds)

    def __enter__(self):
        self._add_signal()

    def __exit__(self, exc_type, exc_val, exc_tb):
        signal.alarm(0)
        signal.signal(signal.SIGALRM, self._default)