Assign output of os.system to a variable and prevent it from being displayed on the screen [duplicate]

Answer 1

From "Equivalent of Bash Backticks in Python", which I asked a long time ago, what you may want to use is popen:

os.popen('cat /etc/services').read()

From the docs for Python 3.6,

This is implemented using subprocess.Popen; see that class’s documentation for more powerful ways to manage and communicate with subprocesses.

---

Here's the corresponding code for subprocess:

import subprocess

proc = subprocess.Popen(["cat", "/etc/services"], stdout=subprocess.PIPE, shell=True)
(out, err) = proc.communicate()
print "program output:", out

Answer 2

Python 2.6 and 3 specifically say to avoid using PIPE for stdout and stderr.

The correct way is

import subprocess

# must create a file object to store the output. Here we are getting
# the ssid we are connected to
outfile = open('/tmp/ssid', 'w');
status = subprocess.Popen(["iwgetid"], bufsize=0, stdout=outfile)
outfile.close()

# now operate on the file

Answer 3

The commands module is a reasonably high-level way to do this:

import commands
status, output = commands.getstatusoutput("cat /etc/services")

status is 0, output is the contents of /etc/services.

Answer 4

For python 3.5+ it is recommended that you use the run function from the subprocess module. This returns a CompletedProcess object, from which you can easily obtain the output as well as return code. Since you are only interested in the output, you can write a utility wrapper like this.

from subprocess import PIPE, run

def out(command):
    result = run(command, stdout=PIPE, stderr=PIPE, universal_newlines=True, shell=True)
    return result.stdout

my_output = out("echo hello world")
# Or
my_output = out(["echo", "hello world"])

Answer 5

i do it with os.system temp file:

import tempfile,os
def readcmd(cmd):
    ftmp = tempfile.NamedTemporaryFile(suffix='.out', prefix='tmp', delete=False)
    fpath = ftmp.name
    if os.name=="nt":
        fpath = fpath.replace("/","\\") # forwin
    ftmp.close()
    os.system(cmd + " > " + fpath)
    data = ""
    with open(fpath, 'r') as file:
        data = file.read()
        file.close()
    os.remove(fpath)
    return data

Answer 6

from os import system, remove
from uuid import uuid4

def bash_(shell_command: str) -> tuple:
    """

    :param shell_command: your shell command
    :return: ( 1 | 0, stdout)
    """

    logfile: str = '/tmp/%s' % uuid4().hex
    err: int = system('%s &> %s' % (shell_command, logfile))
    out: str = open(logfile, 'r').read()
    remove(logfile)
    return err, out

# Example: 
print(bash_('cat /usr/bin/vi | wc -l'))
>>> (0, '3296\n')```