Harry Wang

I find I have to tell developers (sometimes even developers with a few years' experience) again and again how to properly manage environment variables - so I write this simple post so that I can just send a link.

Don'ts

Don'ts: DO NOT ever write the keys in your code - you will forget and push the keys to your repo.

Dos

Do one of the followings (I use OPENAI_API_KEY as an example and my preferred way is method 2):

use export command

Open terminal and run export OPENAI_API_KEY=sk-xxxxxxx

Test that key is correctly set as an environment variable

import os

if os.getenv("OPENAI_API_KEY") is not None:
    print("OPENAI_API_KEY is ready")
else:
    print("OPENAI_API_KEY environment variable not found")

use .env file

create a .env file in the root of the project folder to store the environment variables - this file is gitignored by default (or add this file to .gitignore)
create requirements.txt and include packages to install by putting the following lines in the file (two packages as examples):
```
openai
python-dotenv
```
create a virtual environment and install the packages specified in requirements.txt:
```
python -m venv venv
source venv/bin/activate
pip install -r requirements.txt
```

load keys from .env file:

import openai
import os
from dotenv import load_dotenv

load_dotenv()
openai.api_key = os.getenv('OPENAI_API_KEY')

Method 2 above is my preferred way especially when you have many environment variables to manage.

PS. The featured image for this post is generated using HiddenArt tool from Takin.ai.

Manage Environment Variables in Python Projects

Don'ts

Dos