How to Load envrc Files in Python

import os
import tempfile
from pathlib import Path
from unittest.mock import patch


def load_envrc(envrc_path):
    """Parse an envrc-style file and apply it to the current environment."""
    env_changes = {}
    with open(envrc_path, "r") as f:
        for line in f:
            line = line.strip()
            if line and not line.startswith("#") and "=" in line:
                key, value = line.split("=", 1)
                env_changes[key.strip()] = value.strip().strip('"\'')
    return env_changes


def apply_env(env_changes):
    """Apply parsed env changes to os.environ."""
    for key, value in env_changes.items():
        os.environ[key] = value


def main():
    with tempfile.NamedTemporaryFile(mode="w", suffix=".envrc", delete=False) as tmp:
        tmp.write('export PROJECT_NAME="demo-app"\nexport DEBUG=true\n')
        envrc_path = tmp.name

    try:
        changes = load_envrc(envrc_path)
        apply_env(changes)
        assert os.environ["PROJECT_NAME"] == "demo-app"
        assert os.environ["DEBUG"] == "true"
        print("Environment loaded successfully:")
        print(f"PROJECT_NAME={os.environ['PROJECT_NAME']}")
        print(f"DEBUG={os.environ['DEBUG']}")
    finally:
        Path(envrc_path).unlink()


if __name__ == "__main__":
    main()