return value from python script to shell script

Question

I am new in Python. I am creating a Python script that returns a string "hello world." And I am creating a shell script. I am adding a call from the shell to a Python script.

i need to pass arguments from the shell to Python.
i need to print the value returned from Python in the shell script.

This is my code:

shellscript1.sh

#!/bin/bash
# script for testing
clear
echo "............script started............"
sleep 1
python python/pythonScript1.py
exit

pythonScript1.py

#!/usr/bin/python
import sys

print "Starting python script!"
try:
    sys.exit('helloWorld1') 
except:
     sys.exit('helloWorld2')

Ali Nikneshan · Accepted Answer · 2015-12-09T09:29:14.860

62

You can't return message as exit code, only numbers. In bash it can accessible via $?. Also you can use sys.argv to access code parameters:

import sys
if sys.argv[1]=='hi':
    print 'Salaam'
sys.exit(0)

in shell:

#!/bin/bash
# script for tesing
clear
echo "............script started............"
sleep 1
result=`python python/pythonScript1.py "hi"`
if [ "$result" == "Salaam" ]; then
    echo "script return correct response"
fi

edited Dec 09 '15 at 09:29

answered Dec 09 '15 at 06:13

Ali Nikneshan

3,500
27
39

1

thanks ali. this code is working fine. but i need to return a string value. how it will be possible? – Abdul Manaf Dec 09 '15 at 06:38
4

you should capture python result: a=\`python python/pythonScript1.py "test"\``; echo $a will print what you print in python code – Ali Nikneshan Dec 09 '15 at 09:24
In my case, sys.exit(0) doesn't return anything and the shell script stops as well. But print(0) works well. What happens in my case? – zhangboyu Nov 30 '21 at 02:11
@zhangboyu , I guess you use ' instead of ` – Ali Nikneshan Dec 01 '21 at 04:56
@AliNikneshan I really used ` – zhangboyu Dec 01 '21 at 06:47
@AliNikneshan I noticed what happened. In shell script I set -e, so it stoped while exit(). Is there any other way to get the value while setting -e? – zhangboyu Dec 01 '21 at 07:20

score 10 · Answer 2 · answered Dec 09 '15 at 06:02

10

Pass command line arguments to shell script to Python like this:

python script.py $1 $2 $3

Print the return code like this:

echo $?

answered Dec 09 '15 at 06:02

coffee-converter

967
4
13

score 3 · Answer 3 · answered Feb 24 '22 at 22:14

3

You can also use exit() without sys; one less thing to import. Here's an example:

$ python
>>> exit(1)
$ echo $?
1

$ python
>>> exit(0)
$ echo $?
0

answered Feb 24 '22 at 22:14

Samuel

8,063
8
45
41

The exit() is defined in site.py and it works only if the site module is imported so it should be used in the interpreter only. https://www.scaler.com/topics/exit-in-python/ https://www.geeksforgeeks.org/python-exit-commands-quit-exit-sys-exit-and-os-_exit/ – bgrupczy May 16 '23 at 01:03

return value from python script to shell script

3 Answers3

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