How to timeout when executing command line programs in Python?

Question

I am executing Maple from Python and would like to stop the program if it exceeds a maximum time. If its a Python function this can be done by using a timeout-decorator. But I a

Answer 1

You can use subprocess.Popen to spawn a child process. Make sure to handle stdout and stderr properly. Then use Popen.wait(timeout) call and kill the process when TimeoutExpired arrive.

Answer 2

I think you can use

threading.Timer(TIME, function , args=(,))

To execute function after a delay

Answer 3

Use subprocess.Popen() to do your bidding, if you're using Python version prior to 3.3 you'll have to do handle the timeout yourself, tho:

import subprocess
import sys
import time

# multi-platform precision clock
get_timer = time.clock if sys.platform == "win32" else time.time

timeout = 10  # in seconds

# don't forget to set STDIN/STDERR handling if you need them...
process = subprocess.Popen(["maple", "args", "and", "such"])
current_time = get_timer()
while get_timer() < current_time + timeout and process.poll() is None:
    time.sleep(0.5)  # wait half a second, you can adjust the precision
if process.poll() is None:  # timeout expired, if it's still running...
    process.terminate()  # TERMINATE IT! :D

In Python 3.3+ it's as easy as calling: subprocess.run(["maple", "args", "and", "such"], timeout=10)