Python to call another python without waiting for it to complete using os or subprocess

Question

I have a python script. Which is running as a service with a while loop for ever. The script need to be executed by another python but without waiting for the out put it should pass through.

So the main script with while loop is as follows "main.py". Which never going to be end.

while True:
    # do some task
    time.sleep(5)

This need to be executed by another python "start.py" with similar function as follows.

os.system("main.py 1")

OR

subprocess.Popen("python main.py")

Problem here "start.py" won't finish as witing for the out put of "main.py". But I want to make it like "start.py" need to load "main.py" and leave it in background. Then the "start.py" need to complete the process. How can I modify the

os.system("main.py 1")

function to skip the waiting for "main.py"? Please consider this need to run on cross platform.

why not use `subprocess.Popen`? os.system is going to wait for the process to return, Popen won't, you could also use `&` to background the process — Padraic Cunningham, Dec 16 '15 at 12:46
see http://stackoverflow.com/questions/3516007/run-process-and-dont-wait — kamushin, Dec 16 '15 at 12:46
subprocess.Popen is fine. But still it keeping the console with the next script execute. — sugunan, Dec 16 '15 at 12:56
Isn't using & to background just a shell feature? Which won't for windows. — dalore, Dec 16 '15 at 13:04
@sugunan, `subprocess.Popen("python main.py")` would not run, it would also won't wait for `main.py` to finish — Padraic Cunningham, Dec 16 '15 at 13:22

score 0 · Answer 1 · answered Dec 16 '15 at 13:03

0

I recommend for you to check out Plumbum https://plumbum.readthedocs.org/en/latest/ specifically the section on background/foreground https://plumbum.readthedocs.org/en/latest/#foreground-and-background-execution

from plumbum import BG
from plumbum.cmd import python

python('main.py', '1') & BG

Cross platform also.

answered Dec 16 '15 at 13:03

dalore

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No Module named plumbum error come. – sugunan Dec 16 '15 at 13:05
have you installed it? – dalore Dec 16 '15 at 13:17

Python to call another python without waiting for it to complete using os or subprocess

1 Answers1