Environment-Based Configuration for Python Projects

env_setup_for_production.md

🌐 Environment-Based Configuration for Python Projects

This guide explains how to manage different environments (development, staging, production) using .env files and Python's dotenv.

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✅ Project Structure

project-root/
├── .env                 # Optional: base ENV loader
├── .env.dev             # Development environment variables
├── .env.stage           # Staging environment variables
├── .env.prod            # Production environment variables
├── load\_env.py          # Environment loader script
└── main.py              # Your app entry point

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📜 load_env.py

import os
from dotenv import load_dotenv

# Load base .env (optional) to fetch ENV variable
load_dotenv(".env")

# Get current ENV type
env_type = os.getenv("ENV", "development")
print("ENV from system:", env_type)

# Map ENV to corresponding .env file
env_file = {
    "development": ".env.dev",
    "stage": ".env.stage",
    "production": ".env.prod",
}.get(env_type)

if env_file is None:
    raise ValueError("Unknown ENV value. Must be one of: development, stage, production.")

print(f"Using environment file: {env_file}")

# Load the appropriate environment file
load_dotenv(dotenv_path=env_file, override=True)

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📄 Environment Files

.env.dev

ENV=development
DB_NAME=dev_ai_db
DB_USERNAME=dev_ai_user
DB_PASSWORD=dev_password
DB_HOST=localhost
DB_PORT=5432

.env.stage

ENV=stage
DB_NAME=stage_ai_db
DB_USERNAME=stage_ai_user
DB_PASSWORD=stage_password
DB_HOST=staging-db.example.com
DB_PORT=5432

.env.prod

ENV=production
DB_NAME=ai_db
DB_USERNAME=ai_user
DB_PASSWORD=prod_password
DB_HOST=prod-db.example.com
DB_PORT=5432

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🚀 How to Run

PowerShell / VSCode Terminal (Windows)

$env:ENV="stage"; python main.py

CMD (Classic Command Prompt)

set ENV=stage && python main.py

Alternative: Use .env for ENV value

Set ENV=stage in a .env file:

ENV=stage

Then run:

python main.py

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🛡 Best Practices

• ❌ Never commit .env.prod to version control.
• ✅ Use .env + load_env.py for safer config switching.
• ✅ Use override=True in load_dotenv to avoid conflict.
• ✅ Confirm loaded file with a print() for debugging.

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Happy coding! 🧠⚙️