how to set environment variable from .env file in python script?
The python-dotenv package can do the heavy lifting for you:
from dotenv import load_dotenv load_dotenv(dotenv_path='OCSSW_bash.env')
Kevin LeeUpdated on June 15, 2022
Kevin Lee 7 months
In the Ubuntu bash shell, I can set the environment variable from the .env file by using command lines "source" (example:
sourceis not a function in python. So, how to set an environment variable from the .env file in python？
'l2gen'is a command line program of SeaDAS which be supported by NASA for processing ocean satellite data. I can run it in the bash shell. now, the more program needs to be coded with python script and 'l2gen' is one of program.
But the environment variable needs to be set again in python script. According to the google search result, I fond some method to set the environment variable in python. But lacking information about the .env file.
in the Linux bash shell, I set the environment variable by vim and source:
vim .profile export OCSSWROOT=[SeaDAS_install_dir]/ocssw (adding this in the profile file and then save/exit) source $OCSSWROOT/OCSSW_bash.env
where: SeaDAS_install_dir is the directory where I installed software SeaDAS.
I try to add the environment variable as following:
import subprocess if __name__=='__main__': l2cmdtest = 'l2gen -h' new_env = os.environ.copy() new_env['OCSSWROOT'] = '/usr/local/seadas-7.5.3/ocssw' new_env['OCSSWROOT'] = 'OCSSWROOT/OCSSW_bash.env' eturnCodetest = subprocess.call(l2cmdtest, shell=True)
where: 'l2gen -h' is a program which can work in the bash shell.
executing python script, and then an error:
/bin/sh: 1: l2gen: not found
Kevin Lee over 3 yearsthanks. But how to link an environment variable to .env file?
Mureinik over 3 years@KevinLee I'm not sure I understand the question. You edit the
.envfile with the variables you need (e.g.,
MYVAR=123), and use
load_dotenvto load this file. It places all entries there as environment variables, and any subsequent part of your code that relies on environment variables will be able to use them.
Kevin Lee over 3 yearsthanks very much. I solved this problem by as following code. commands = 'source $OCSSWROOT/OCSSW_bash.env;' +l2gencmd1 process=subprocess.Popen(commands,executable='/bin/bash',stdin=subprocess.PIPE,stdout=subprocess.PIPE, shell=True) out, err = process.communicate() where commands consists of two parts. 'source $OCSSWROOT/OCSSW_bash.env;' is the setting environment variable.