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While there are many questions regarding accessing/ setting env variables in python, I could not find the answer for my particular scenario.

I have a shell script that when called it does the export of a bunch of env variables that are used later on.

When you need those variables to be available from your current session, then you would do

. ./script_exp_var.sh

that does, say

export MYVAR = MYVAL

then if you run python, you could access it with os.environ.get('MYVAR').

My question is how to invoke the script from python and then to have to access the env variables that called script just exported. Is it possible at all and if yes how? Note: I know I could set the env var from python using os.environ["MYVAR"] = MYVAL but I would like to use the existing logic in my ./script_exp_var.sh because it exports many variables. Also making sure to execute the script first and then execute the python is also not an option for my scenario.

Reza Mousavi
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vadimboy
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  • Possible duplicate of [Set environment variable of calling bash script in python](https://stackoverflow.com/questions/49201028/set-environment-variable-of-calling-bash-script-in-python) – cdarke Sep 22 '18 at 09:14
  • By the way, `export MYVAR = MYVAL` is invalid in shell, there are no spaces allowed around an `=`. – cdarke Sep 22 '18 at 09:15

1 Answers1

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You can't. Environment variables are copied from parent to child, never back to the parent.

If you execute a shell script from python then the environment variables will be set in that shell process (the child) and python will be unaware of them.

You could write a parser to read the shell commands from python, but that's a lot of work.

Better to write a shell script with the settings in that and then call the python program as a child of the script.

Alternatively, write a shell script that echoes the values back to python which can be picked-up using a pipe.

cdarke
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