python限制函数的执行时间

# 0x0001
```
from multiprocessing import Process
from time import sleep

def f(time):
    sleep(time)
    print(time)

def run_with_limited_time(func, args, kwargs, time):

p = Process(target=func, args=args, kwargs=kwargs)
    p.start()
    p.join(time)
    if p.is_alive():
        p.terminate()
        return False

return True

if __name__ == '__main__':
    print(run_with_limited_time(f, (1.5, ), {}, 2.5)) # True
    print(run_with_limited_time(f, (3.5, ), {}, 2.5)) # False

```

# 0x0002

```
from contextlib import contextmanager
import threading
import _thread

class TimeoutException(Exception):
    def __init__(self, msg=''):
        self.msg = msg

@contextmanager
def time_limit(seconds, msg=''):
    timer = threading.Timer(seconds, lambda: _thread.interrupt_main())
    timer.start()
    try:
        yield
    except KeyboardInterrupt:
        raise TimeoutException("Timed out for operation {}".format(msg))
    finally:
        # if the action ends in specified time, timer is canceled
        timer.cancel()

import time
# ends after 5 seconds
with time_limit(5, 'sleep'):
    n=0
    for i in range(10):
        n=n+1
        print(n)
        time.sleep(1)

```

# 参考
- <https://stackoverflow.com/questions/366682/how-to-limit-execution-time-of-a-function-call-in-python>