Introduction to User Authentication: Implementing Simple Login and Permission Control with Flask Session

This article introduces implementing user authentication and permission control for web applications using the Flask framework and Session mechanism, suitable for beginners. It first clarifies the concepts of user authentication (verifying identity) and permission control (judging access rights), emphasizing that Session is used to store user status, and Flask's `session` object supports direct manipulation. For environment preparation, install Flask, create an application, and configure `secret_key` to encrypt sessions. To implement the login function: collect username and password through a form, verify them (simulating a user database), set `session['username']`, and redirect to the personal center upon successful login. For permission control, use the `@login_required` decorator to check the Session and protect pages requiring login (e.g., the personal center). Logout clears the user status by `session.pop('username')`. Core content includes: Session basics, login verification, permission decorators, and logout functionality. The article summarizes the learned knowledge points and expands on directions such as database connection, password encryption, and multi-role permissions. Flask Session provides a simple and secure solution that can be gradually used to build complex applications.