Environment Variables Not Loaded from .env

Why This Happens

Python does not read .env files by default. You need python-dotenv to load them. Common issues: forgetting load_dotenv(), wrong directory, or bad formatting.

The Problem

import os
secret = os.environ['SECRET_KEY']

The Fix

import os
from dotenv import load_dotenv
load_dotenv()
secret = os.environ.get('SECRET_KEY')

Step-by-Step Fix

1. 1

   Install python-dotenv

   pip install python-dotenv.

2. 2

   Call load_dotenv()

   Add at entry point before accessing env vars.

3. 3

   Check .env format

   Use KEY=value without spaces around =.