Introduction to Python Dotenv Package¶

The python-dotenv package is a library that allows you to store sensitive data such as API keys, database credentials, and other environment-specific settings in a .env file. This file is not committed to version control, ensuring that your sensitive data remains secure.

Why Use Dotenv?¶

Keeps sensitive data separate from code
Easy to switch between development, testing, and production environments
Reduces the risk of exposing sensitive data in version control

Installation¶

To install the python-dotenv package, run the following command:

pip install python-dotenv

Basic Usage¶

Here's an example of how to use python-dotenv:

Step 1: Create a `.env` File¶

Create a new file named .env in the root of your project directory:

DB_HOST=localhost
DB_PORT=5432
DB_USER=myuser
DB_PASSWORD=mypassword

Step 2: Load Environment Variables¶

In your Python script, load the environment variables from the .env file using the load_dotenv function:

import os
from dotenv import load_dotenv

load_dotenv()  # loads variables from .env file

db_host = os.getenv('DB_HOST')
db_port = os.getenv('DB_PORT')
db_user = os.getenv('DB_USER')
db_password = os.getenv('DB_PASSWORD')

print(f"DB Host: {db_host}")
print(f"DB Port: {db_port}")
print(f"DB User: {db_user}")
print(f"DB Password: {db_password}")

Example Use Case: Database Connection¶

Here's an example of using python-dotenv to connect to a PostgreSQL database:

import os
import psycopg2
from dotenv import load_dotenv

load_dotenv()

db_host = os.getenv('DB_HOST')
db_port = os.getenv('DB_PORT')
db_user = os.getenv('DB_USER')
db_password = os.getenv('DB_PASSWORD')
db_name = os.getenv('DB_NAME')

try:
    conn = psycopg2.connect(
        host=db_host,
        port=db_port,
        user=db_user,
        password=db_password,
        database=db_name
    )
    print("Connected to database!")
except psycopg2.Error as e:
    print(f"Error connecting to database: {e}")

In this example, the database connection settings are stored in the .env file, and the python-dotenv package is used to load these settings into the Python script.

Best Practices¶

Keep your .env file out of version control by adding it to your .gitignore file.
Use meaningful variable names in your .env file.
Keep your .env file organized by grouping related variables together.

By following these best practices and using the python-dotenv package, you can keep your sensitive data secure and make it easy to switch between different environments.