Store output of subprocess.Popen call in a string Store output of subprocess.Popen call in a string python python

Store output of subprocess.Popen call in a string


In Python 2.7 or Python 3

Instead of making a Popen object directly, you can use the subprocess.check_output() function to store output of a command in a string:

from subprocess import check_outputout = check_output(["ntpq", "-p"])

In Python 2.4-2.6

Use the communicate method.

import subprocessp = subprocess.Popen(["ntpq", "-p"], stdout=subprocess.PIPE)out, err = p.communicate()

out is what you want.

Important note about the other answers

Note how I passed in the command. The "ntpq -p" example brings up another matter. Since Popen does not invoke the shell, you would use a list of the command and options—["ntpq", "-p"].


This worked for me for redirecting stdout (stderr can be handled similarly):

from subprocess import Popen, PIPEpipe = Popen(path, stdout=PIPE)text = pipe.communicate()[0]

If it doesn't work for you, please specify exactly the problem you're having.


Python 2: http://docs.python.org/2/library/subprocess.html#subprocess.Popen

from subprocess import PIPE, Popencommand = "ntpq -p"process = Popen(command, stdout=PIPE, stderr=None, shell=True)output = process.communicate()[0]print output

In the Popen constructor, if shell is True, you should pass the command as a string rather than as a sequence. Otherwise, just split the command into a list:

command = ["ntpq", "-p"]process = Popen(command, stdout=PIPE, stderr=None)

If you need to read also the standard error, into the Popen initialization, you should set stderr to PIPE or STDOUT:

command = "ntpq -p"process = subprocess.Popen(command, stdout=PIPE, stderr=PIPE, shell=True)output, error = process.communicate()

NOTE: Starting from Python 2.7, you could/should take advantage of subprocess.check_output (https://docs.python.org/2/library/subprocess.html#subprocess.check_output).


Python 3: https://docs.python.org/3/library/subprocess.html#subprocess.Popen

from subprocess import PIPE, Popencommand = "ntpq -p"with Popen(command, stdout=PIPE, stderr=None, shell=True) as process:    output = process.communicate()[0].decode("utf-8")    print(output)

NOTE: If you're targeting only versions of Python higher or equal than 3.5, then you could/should take advantage of subprocess.run (https://docs.python.org/3/library/subprocess.html#subprocess.run).


matomo