Python flask-login 模块：初学者必读

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

app = Flask(__name__)
app.secret_key = 'mysecret'  # 设置密钥用于会话加密
login_manager = LoginManager()
login_manager.init_app(app)

# 模拟用户数据库
users = {'user': {'password': 'password123'}}

class User(UserMixin):
    pass

# 用户加载回调函数
@login_manager.user_loader
def load_user(username):
    user = User()
    user.id = username
    return user if username in users else None

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':  # 检查请求方法是否为POST
        username = request.form['username']  # 获取用户名
        password = request.form['password']  # 获取密码
        if username in users and users[username]['password'] == password:  # 验证用户名和密码
            user = User()
            user.id = username
            login_user(user)  # 登录用户
            return redirect(url_for('protected'))  # 登录成功后重定向
    return render_template('login.html')  # 渲染登录页面

@app.route('/protected')
@login_required  # 保护的路由，需要登录才能访问
def protected():
    return f'Logged in as: {current_user.id}'  # 返回当前登录的用户

@app.route('/logout')
@login_required
def logout():
    logout_user()  # 登出用户
    return redirect(url_for('login'))  # 重定向到登录页面

if __name__ == '__main__':
    app.run(debug=True)  # 启动 Flask 应用

from flask import Flask, abort
from flask_login import LoginManager, login_required

app = Flask(__name__)
login_manager = LoginManager()
login_manager.init_app(app)

# 假设已存在用户管理轮廓

@app.route('/admin')
@login_required  # 只有登录用户可以访问
def admin():
    return 'Welcome to the admin panel!'  # 返回管理面板

@app.route('/not_authenticated')
def not_authenticated():
    abort(403)  # 如果用户未登录则返回403状态码

if __name__ == '__main__':
    app.run(debug=True)  # 启动 Flask 应用

from flask import Flask, session
from flask_login import LoginManager, login_user, logout_user

app = Flask(__name__)
app.secret_key = 'mysecret'  # 设置密钥用于会话加密
login_manager = LoginManager()
login_manager.init_app(app)

@app.route('/login', methods=['POST'])
def login():
    username = request.form['username']  # 获取用户名
    # 登录逻辑在此
    login_user(user)  # 登录用户
    session['original'] = request.url  # 记录原始请求URL

@app.route('/redirect_after_login')
def redirect_after_login():
    return redirect(session.pop('original', '/'))  # 登录后重定向用户

if __name__ == '__main__':
    app.run(debug=True)  # 启动 Flask 应用