Python中如何使用Flask-Login？

pip install flask-login

from flask import Flask, redirect, url_for, request, render_template
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user

app = Flask(__name__)
app.config['SECRET_KEY'] = 'your-secret-key'  # 用于会话加密

# 初始化LoginManager
login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'  # 如果用户未登录，将重定向到login视图

# 定义一个用户类，继承自UserMixin
class User(UserMixin):
    def __init__(self, id):
        self.id = id

# 模拟用户数据库
users = {'testuser': User(1)}

# 加载用户的回调函数
@login_manager.user_loader
def load_user(user_id):
    for user in users.values():
        if user.id == int(user_id):
            return user
    return None

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form['username']
        if username in users:
            user = users[username]
            login_user(user)
            return redirect(url_for('protected'))
    return render_template('login.html')

@app.route('/protected')
@login_required
def protected():
    return f'Logged in as: {current_user.id}'

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

if __name__ == '__main__':
    app.run(debug=True)