Description#
For example, database connection information usually corresponds to two different configurations in testing and production environments.
This article is based on the Python Flask framework.
If you want to use a .env file to configure different environments, refer to: Python: Configure environment variables in different environments through .env file
Create Configuration Files#
First, you need to create a base class that contains all the configurations used in the project:
# config/base.py
class Base:
SERVICE_NAME: str = 'service a'
DB_HOST: str = 'base://'
Then create configuration files for testing and production environments, both inheriting from the Base configuration class:
# config/dev.py
class Dev(Base):
DB_HOST: str = 'dev://'
# config/prod.py
class Prod(Base):
DB_HOST: str = 'prod://'
Create init.py#
Having created the configurations for the two environments, we will now create a utility function in the __init__.py file in the current directory that loads different configuration files based on the current environment. At the same time, we will directly declare an instance (singleton) so that other places can directly read the configuration through this instance:
# config/__init__.py
import os
from config.dev import Dev
from config.prod import Prod
def _get_config():
'''Create a Config instance based on the current environment'''
env = os.getenv('FLASK_ENV', 'development')
if env == 'development':
return Dev()
else:
return Prod()
current_config = _get_config()
Import Configuration into Flask Framework#
Finally, after instantiating Flask, import the current_config declared in the above __init__.py:
from config import current_config
app = Flask(__name__)
app.config.from_object(current_config)
Read Configuration#
We can use the following methods to get the configuration key values:
from config import current_config
app = Flask(__name__)
app.config.from_object(current_config)
# Method 1: Get from Flask
app.config.get('DB_HOST')
# Method 2: Get from the instance in config/__init__.py
current_config.DB_HOST