Technology Tales

Loading API Keys from Linux shell environment variables in Python with Dotenv

Published on 23^rd October 2025 Estimated Reading Time: 2 minutes

Recently, I ran into trouble with getting Python to pick up an API key that I had defined in the underlying bash environment. This was within a Python console running inside the Positron IDE for R and Python scripting. Opening up the folder containing my Python scripts within the IDE was part of the solution. The next part was creating a .env file within the same folder. A line like this was added within the new file:

export API_KEY="<API key value>"

That meant that code like the following then read in the API key in a more robust manner:

import os
from dotenv import load_dotenv
load_dotenv()
api_key = os.getenv('API_KEY', 'default_value')

This imports the os module and the load_dotenv method from the dotenv package. Then, load_dotenv is executed to load the .env file and its contents. After that, the os.getenv function can assign the API key to a Python variable from the value of the environment variable.

Since this also was within a Git repository, a .gitignore file needed creating with the contents .env to avoid that file being uploaded to GitHub, which is the last place where you should be storing credentials like passwords, passphrases and API keys. While my repository may be private, the state of things at these troubled times mean that even that is no failsafe.