using a shell script within python

[snippsat]

Should not be using os.system(),subprocess replace it a better/safer way.
Ideally is better/safer to pass in a list.

import subprocess

subprocess.run(['ls', '-l'])

Passing in a string has to use shell=True

import subprocess

subprocess.run('ls -l', shell=True)

So as shown bye @volcano63 can pass in using f-string or format(),
but the method with list when shell=False is advisable.

import subprocess

arg = '-l'
subprocess.run(f'ls {arg}', shell=True)

The subprocess has a lot stuff that make it better,even run(that replace call) can now also catch output.

import subprocess

out = subprocess.run(['ls', '-l'], capture_output=True)
print(out.stdout.decode())