Call Python From Bat File And Get Return Code

Question

I'm looking for a way to call a python script from a batch file and getting a return code from the python script. Confusing I know, but it's based on a system that's currently in use. I'd re-write it, but this way would be much, much quicker.

So:

Bat ---------------------> Python
     * call python file *

Bat <--------------------------------- Python
      * python does a load of work *
      * and returns a return code  *

Answer 1

The windows shell saves the return code in the ERRORLEVEL variable:

python somescript.py
echo %ERRORLEVEL%

In the python script you can exit the script and set the return value by calling exit() :

exit(15)

In older versions of python you might first have to import the exit() function from the sys module:

from sys import exit
exit(15)

Answer 2

Try:

import os
os._exit(ret_value)

You should also check:

• sys.exit()

Answer 3

You can try this batch script for this:

@echo off

REM     %1 - This is the parameter we pass with the desired return code for the Python script that will be captured by the ErrorLevel env. variable.  
REM     A value of 0 is the default exit code, meaning it has all gone well. A value greater than 0 implies an error
REM     and this value can be captured and used for any error control logic and handling within the script
   
set ERRORLEVEL=
set RETURN_CODE=%1

echo (Before Python script run) ERRORLEVEL VALUE IS: [ %ERRORLEVEL% ]
echo.

call python -c "import sys; exit_code = %RETURN_CODE%; print('(Inside python script now) Setting up exit code to ' + str(exit_code)); sys.exit(exit_code)"

echo.
echo (After Python script run) ERRORLEVEL VALUE IS: [ %ERRORLEVEL% ]
echo.

And when you run it a couple of times with different return code values you can see the expected behaviour:

PS C:\Scripts\ScriptTests> & '\TestPythonReturnCodes.cmd' 5

(Before Python script run) ERRORLEVEL VALUE IS: [ 0 ]

(Inside python script now) Setting up exit code to 5

(After Python script run) ERRORLEVEL VALUE IS: [ 5 ]

PS C:\Scripts\ScriptTests> & '\TestPythonReturnCodes.cmd' 3

(Before Python script run) ERRORLEVEL VALUE IS: [ 0 ]

(Inside python script now) Setting up exit code to 3

(After Python script run) ERRORLEVEL VALUE IS: [ 3 ]

PS C:\Scripts\ScriptTests