Python YAML (PyYAML) with environment file support (python-dotenv)

.env

POSTGRES_DB=postgres
POSTGRES_USER=postgres
POSTGRES_PASSWORD=p@ssw0rd
POSTGRES_HOST=localhost
POSTGRES_PORT=5432

JWT_SECRET=very secret
JWT_ACCESS_EXP=1800
JWT_REFRESH_EXP=864000
JWT_ALGORITHM=HS256

config.py

import os
import pathlib
import re

import yaml
from dotenv import load_dotenv

BASE_DIR = pathlib.Path(__file__)
config_path = BASE_DIR / 'main.yaml'

load_dotenv(dotenv_path=BASE_DIR / '.env')

FROM_ENV_RE = re.compile(r'\${{.+}}')


def parse_env_placeholders(content: str) -> str:
    def replace(match: re.Match):
        value = match.group().strip('${}').strip()
        return os.getenv(value)

    return FROM_ENV_RE.sub(replace, content)


def get_config(path) -> dict:
    with open(path) as f:
        content = f.read()
        parsed = parse_env_placeholders(content)
        cfg = yaml.safe_load(parsed)
    return cfg


config = get_config(config_path)

main.yml

postgres:
  database: ${{ POSTGRES_DB }}
  user: ${{ POSTGRES_USER }}
  password: ${{ POSTGRES_PASSWORD }}
  host: ${{ POSTGRES_HOST }}
  port: ${{ POSTGRES_PORT }}
  minsize: 1
  maxsize: 5
jwt:
  secret: ${{ JWT_SECRET }}
  access_exp: ${{ JWT_ACCESS_EXP }}
  refresh_exp: ${{ JWT_REFRESH_EXP }}
  algorithm: ${{ JWT_ALGORITHM }}
  request_property: jwt_payload

PyYAML https://github.com/yaml/pyyaml
python-dotenv https://github.com/theskumar/python-dotenv