How would I stop a while loop after n amount of time?

Question

how would I stop a while loop after 5 minutes if it does not achieve what I want it to achieve.

while true:
    test = 0
    if test == 5:
        break
    test = test - 1

This code throws me in an endless loop.

Answer 1

Try the following:

import time
timeout = time.time() + 60*5   # 5 minutes from now
while True:
    test = 0
    if test == 5 or time.time() > timeout:
        break
    test = test - 1

You may also want to add a short sleep here so this loop is not hogging CPU (for example time.sleep(1) at the beginning or end of the loop body).

Answer 2

You do not need to use the while True: loop in this case. There is a much simpler way to use the time condition directly:

import time

# timeout variable can be omitted, if you use specific value in the while condition
timeout = 300   # [seconds]

timeout_start = time.time()

while time.time() < timeout_start + timeout:
    test = 0
    if test == 5:
        break
    test -= 1

Answer 3

Try this module: http://pypi.python.org/pypi/interruptingcow/

from interruptingcow import timeout
try:
    with timeout(60*5, exception=RuntimeError):
        while True:
            test = 0
            if test == 5:
                break
            test = test - 1
except RuntimeError:
    pass