How can I call a shell script from Python code?

There are some ways using os.popen() (deprecated) or the whole subprocess module, but this approach

import os
os.system(command)

is one of the easiest.

In case you want to pass some parameters to your shell script, you can use the method shlex.split():

import subprocess
import shlex
subprocess.call(shlex.split('./test.sh param1 param2'))

with test.sh in the same folder:

#!/bin/sh
echo $1
echo $2
exit 0

Outputs:

$ python test.py 
param1
param2

import os
import sys

Assuming test.sh is the shell script that you would want to execute

os.system("sh test.sh")

Use the subprocess module as mentioned above.

I use it like this:

subprocess.call(["notepad"])

I'm running Python 3.5 and subprocess.call(['./test.sh']) doesn't work for me.

I give you three solutions depends on what you want to do with the output.

1 - call the script. You will see output in your terminal. output is a number.

import subprocess

output = subprocess.call(['test.sh'])

2 - call and dump execution and error into a string. You don't see execution in your terminal unless you use print(stdout). Shell=True as the argument in Popen doesn't work for me.

import subprocess
from subprocess import Popen, PIPE

session = subprocess.Popen(['test.sh'], stdout=PIPE, stderr=PIPE)
stdout, stderr = session.communicate()

if stderr:
    raise Exception("Error "+str(stderr))

3 - call the script and dump the echo commands of temp.txt in temp_file

import subprocess

temp_file = open("temp.txt",'w')
subprocess.call([executable], stdout=temp_file)
with open("temp.txt",'r') as file:
    output = file.read()
print(output)

Don't forget to take a look at the document of subprocess.

I stumbled upon this recently, and it ended up misguiding me since the Subprocess API has changed since Python 3.5.

The new way to execute external scripts is with the run function, which runs the command described by the arguments. It waits for the command to complete, and then returns a CompletedProcess instance.

import subprocess

subprocess.run(['./test.sh'])

In case the script is having multiple arguments

#!/usr/bin/python

import subprocess
output = subprocess.call(["./test.sh","xyz","1234"])
print output

Output will give the status code. If script runs successfully it will give 0 otherwise non-zero integer.

podname=xyz  serial=1234
0

Below is the test.sh shell script.

#!/bin/bash

podname=$1
serial=$2
echo "podname=$podname  serial=$serial"

Subprocess module is a good module to launch subprocesses. You can use it to call shell commands as this:

subprocess.call(["ls","-l"]);
#basic syntax
#subprocess.call(args, *)

You can see its documentation here.

If you have your script written in some .sh file or a long string, then you can use os.system module. It is fairly simple and easy to call:

import os
os.system("your command here")
# or
os.system('sh file.sh')

This command will run the script once, to completion, and block until it exits.

If your shell script file does not have execute permissions, do so in the following way.

import subprocess
subprocess.run(['/bin/bash', './test.sh'])

Subprocess is good but some people may like scriptine better. Scriptine has more high-level set of methods like shell.call(args), path.rename(new_name) and path.move(src,dst). Scriptine is based on subprocess and others.

Two drawbacks of scriptine:

• Current documentation level would be more comprehensive even though it is sufficient.
• Unlike subprocess, scriptine package is currently not installed by default.

Using Manoj Govindan's answer, I found that I could run simple shell scripts from Python, but the script I was desperately trying to run would fail with the error

Syntax error: "(" unexpected

I changed the first argument from 'sh' to 'bash', and voilà! Suddenly it executed.

subprocess.call(['bash', './test.sh'])

In order to run a shell script in a Python script and to run it from a particular path in Ubuntu, use the below;

import subprocess

a = subprocess.call(['./dnstest.sh'], cwd = "/home/test")

print(a)

Where CWD is the current working directory.

The below will not work in Ubuntu; here we need to remove 'sh':

subprocess.call(['sh' ,'./dnstest.sh'], cwd = "/home/test")