Wsrtjtyk

I have two python scripts that use two different cameras for a project I am working on and I am trying to run them both inside a different script or within each other, either way is fine.

import os



os.system('python 1.py')



os.system('python 2.py')

My problem however is that they don't run at the same time, I have to quit the first one for the next to open. I also tried doing it with bash as well with the & shell operator

python 1.py &

python 2.py &

And this does in fact make them both run however the issue is that they both run endlessly in the background and I need to close them rather easily. Any suggestion what I can do to avoid the issues with these implementations

You could do it with multiprocessing

import os

import time

import psutil

from multiprocessing import Process



def run_program(cmd):

    # Function that processes will run

    os.system(cmd)



# Initiating Processes with desired arguments

program1 = Process(target=run_program, args=('python 1.py',))

program2 = Process(target=run_program, args=('python 2.py',))



# Start our processes simultaneously

program1.start()

program2.start()



def kill(proc_pid):

    process = psutil.Process(proc_pid)

    for proc in process.children(recursive=True):

        proc.kill()

    process.kill()



# Wait 5 seconds and kill first program

time.sleep(5)

kill(program1.pid)

program1.join()



# Wait another 1 second and kill second program

time.sleep(1)

kill(program2.pid)

program2.join()



# Print current status of our programs

print('1.py alive status: {}'.format(program1.is_alive()))

print('2.py alive status: {}'.format(program2.is_alive()))

One possible method is to use systemd to control your process (i.e. treat them as daemons).

This is how I control my Python servers since they need to run in the background and be completely detached from the current tty so I can exit my connection to the machine and the continue processes continue. You can then also stop the server later using systemctl, as explained below.

Instructions:

Create a .service file and save it in /etc/systemd/system, with contents along the lines of:

[Unit]

Description=daemon one



[Service]

ExecStart=/path/to/1.py

and repeat with one going to 2.py.

Then you can use systemctl to control your daemons.

First reload all config files with:

systemctl daemon-reload

then start either of your daemons (where my_daemon.service is one of your unit files):

systemctl start my_daemon

it should now be running and you should find it in:

systemctl list-units

You can also check its status with:

systemctl status my_daemon

and stop/restart them with:

systemctl stop|restart my_daemon

Use subprocess.Popen. This will create a child process and return its pid.

pid = Popen("python 1.py").pid

And then check out these functions for communicating with the child process and checking if it is still running.