Set environment variable of calling bash script in python [duplicate]

Answer 1

you cannot propagate an environment variable to the parent process. But you can print the variable, and assign it back to the variable name from your shell:

VarFromFirstScript=$(python myOtherScript.py $VarFromFirstScript)

you must not print anything else in your code, or using stderr

sys.stderr.write("Running some code...\n")
VarFromFirstScript = someFunc()
sys.stdout.write(VarFromFirstScript)

an alternative would be to create a file with the variables to set, and make it parse by your shell (you could create a shell that the parent shell would source)

import shlex
with open("shell_to_source.sh","w") as f:
   f.write("VarFromFirstScript={}\n".format(shlex.quote(VarFromFirstScript))

(shlex.quote allows to avoid code injection from python, courtesy Charles Duffy)

then after calling python:

source ./shell_to_source.sh