Description#
The previous article Flask: Loading Different Configuration Files Based on the Current Environment was somewhat cumbersome. Here, I will introduce a method that loads configuration files (.env) into environment variables and then reads the configuration from the environment variables, which is more flexible:
Install Dependencies#
First, you need to install the python-dotenv library:
pip install python-dotenv
Its purpose is to read key-value pairs from the .env file and set them as environment variables.
Create settings.py#
# settings.py
import os
from dotenv import load_dotenv
# Read key-value pairs from the .env file and set them as environment variables
# By default, it reads the .env file, but you can also specify the file path, see: https://stackoverflow.com/a/41547163/7712266
load_dotenv()
class Settings:
SERVICE_NAME: str = os.getenv('SERVICE_NAME', 'service a')
DB_HOST: str = os.getenv('DB_HOST', 'localhost')
# Instantiate a singleton for easy access in other places
settings = Settings()
Create .env#
Next, create a .env file to override the property values inside the Settings.py class:
DB_HOST=dev://
The python-dotenv library looks for the environment variable file named .env by default, but you can also manually specify the file path when calling load_dotenv().
Usage#
The usage is as follows:
from .settings import settings
# Method 1: Access configuration through the instance of the Settings class
settings.DB_HOST
# Method 2: Directly read the environment variable
os.getenv('DB_HOST', 'localhost')