Essential for Beginners: Configuring Flask Files and Environment Variables

This article introduces methods for Flask application configuration management, with the core being the use of configuration files and environment variables to enhance flexibility and security. Configuration files (e.g., config.py) are used to centrally manage non-sensitive configurations. They distinguish different environments (development/production) through classes like BaseConfig, DevelopmentConfig, and ProductionConfig. In app.py, the corresponding configuration is loaded based on the FLASK_ENV environment variable: for example, enabling DEBUG and using SQLite in development, while disabling DEBUG and configuring PostgreSQL in production. Environment variables are used to manage sensitive information (such as SECRET_KEY and database passwords). After setting them at the system level, they are read via os.environ.get to avoid exposing code. During development, the .env file and python-dotenv library can simplify operations: define variables in .env, and load_dotenv() in the code automatically loads them. Additionally, .env should be added to .gitignore. Best practices include: environment variables taking precedence over configuration files, separating configurations for different environments (SQLite and DEBUG for development, environment-variable-based database connections for production), and ensuring sensitive information is always stored in environment variables. By reasonably combining these three methods, the application becomes more flexible, secure, and easy to deploy.