安裝Flask-Login

pip install Flask-Login

app.py

from flask import Flask, jsonify, request, abort, redirect, url_for
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager, UserMixin, login_user, logout_user, login_required, current_user

app = Flask(__name__)
app.config['SECRET_KEY'] = 'your_secret_key_here'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///users.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

db = SQLAlchemy(app)
login_manager = LoginManager(app)
login_manager.login_view = 'login'

# 用戶模型
class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(150), unique=True, nullable=False)
    password = db.Column(db.String(150), nullable=False)

@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        user = User.query.filter_by(username=username).first()
        if user and user.password == password:
            login_user(user)
            return redirect(url_for('dashboard'))
        else:
            return 'Invalid credentials', 401
    return '''
        <form method="POST">
            <input type="text" name="username" placeholder="Username" required><br>
            <input type="password" name="password" placeholder="Password" required><br>
            <input type="submit" value="Login">
        </form>
    '''

@app.route('/logout')
@login_required
def logout():
    logout_user()
    return redirect(url_for('login'))

@app.route('/dashboard')
@login_required
def dashboard():
    return f'Hello, {current_user.username}! Welcome to your dashboard.'

@app.route('/protected')
@login_required
def protected():
    return 'This is a protected route. You are logged in.'

if __name__ == '__main__':
    db.create_all()  # 創建數據庫
    app.run(debug=True)

使用 SQLAlchemy 的交互式 shell 來創建用戶：

>>> from app import db, User
>>> user = User(username='admin', password='admin')
>>> db.session.add(user)
>>> db.session.commit()

確保安裝所有必要的依賴

pip install Flask Flask-Login Flask-SQLAlchemy

設置 FLASK_APP 環境變量
Windows 上（命令提示符）

set FLASK_APP=app.py

啟動 Flask 應用

flask run