Run python script only if it's not running

问题

I want to launch a python script from another python script. I know how to do it. But I should launch this script only if it is not running already.

code:

import os
os.system("new_script.py")

But I'm not sure how to check if this script is already running or not.

回答1:

Try this:

import subprocess
import os 

p = subprocess.Popen(['pgrep', '-f', 'your_script.py'], stdout=subprocess.PIPE)
out, err = p.communicate()

if len(out.strip()) == 0:
    os.system("new_script.py")

回答2:

Came across this old question looking for solution myself.

Use psutil:

import psutil
import sys
from subprocess import Popen

for process in psutil.process_iter():
    if process.cmdline() == ['python', 'your_script.py']:
        sys.exit('Process found: exiting.')

print('Process not found: starting it.')
Popen(['python', 'your_script.py'])

You can also use start time of the previous process to determine if it's running too long and might be hung:

process.create_time()

There is tons of other useful metadata of the process.

来源：https://stackoverflow.com/questions/37968080/run-python-script-only-if-its-not-running