Store output of subprocess.Popen call in a string

Question

I\'m trying to make a system call in Python and store the output to a string that I can manipulate in the Python program.

#!/usr/bin/python
import subprocess         


        

Answer 1

for Python 2.7+ the idiomatic answer is to use subprocess.check_output()

You should also note the handling of arguments when invoking a subprocess, as it can be a little confusing....

If args is just single command with no args of its own (or you have shell=True set), it can be a string. Otherwise it must be a list.

for example... to invoke the ls command, this is fine:

from subprocess import check_call
check_call('ls')

so is this:

from subprocess import check_call
check_call(['ls',])

however, if you want to pass some args to the shell command, you can't do this:

from subprocess import check_call
check_call('ls -al')

instead, you must pass it as a list:

from subprocess import check_call
check_call(['ls', '-al'])

the shlex.split() function can sometimes be useful to split a string into shell-like syntax before creating a subprocesses... like this:

from subprocess import check_call
import shlex
check_call(shlex.split('ls -al'))