Set a timeout for executing python code in a with statement

basic signal timeout.py

import signal
import re


class TimeoutError(Exception):
    pass


class timeout:

    def __init__(self, seconds=1, error_message='Timeout'):
        self.seconds = seconds
        self.error_message = error_message

    def handle_timeout(self, signum, frame):
        raise TimeoutError(self.error_message)

    def __enter__(self):
        signal.signal(signal.SIGALRM, self.handle_timeout)
        signal.alarm(self.seconds)

    def __exit__(self, type, value, traceback):
        signal.alarm(0)


ua = 'Mozilla/5.0 (X11; Linux x86_64_128) AppleWebKit/11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111.111111111111111111111111111111111111111111111111111111111111111111111111 (KHTML, like Gecko) Linux/222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222'


with timeout(3):
    r = re.compile('^(.*)/(\d+)\.?(\d+)?.?(\d+)?.?(\d+)? CFNetwork')
    print(r.match(ua[:10]) or 'No match with a 10-long substring')

with timeout(3):
    r = re.compile('^(.*)/(\d+)\.?(\d+)?.?(\d+)?.?(\d+)? CFNetwork')
    print(r.match(ua))


# import time
# import random


# ************** timeout test
# with timeout(seconds=3):
#     time.sleep(4)


# ************** exception test
# with timeout(seconds=3):
#    time.sleep(2)
#    raise Exception('a different thing')


# ************** overhead test
# count = 100000
# x = ''
# start = time.time()
# for i in range(count):
#    x = x + str(random.randint(0, count))
# stop = time.time()

# print('without timeout ' + str(stop - start))

# x = ''
# start = time.time()
# with timeout(seconds=5):
#   for i in range(count):
#       x = x + str(random.randint(0, count))
# stop = time.time()

# print('with timeout ' + str(stop - start))