Flask 实现用户登录功能的完整示例：前端与后端整合（附Demo）

前言

对于python用户的登录，以下只是提供一个Demo用于学习

更多的python知识点可从我的专栏中进行学习

python专栏
详细分析Flask中的蓝图Blueprint（附Demo）
详细分析Flask部署云服务器（图文介绍）
构建Flask前后端不分离项目（附Python Demo）

Demo

项目结构：

/project-directory/templateslogin.htmlapp.py

前端登录页面：

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Login</title><style>body {font-family: Arial, sans-serif;background-color: #f4f4f4;}.container {width: 300px;margin: 100px auto;padding: 20px;background-color: white;box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);}h2 {text-align: center;}.form-group {margin-bottom: 15px;}.form-group label {display: block;}.form-group input {width: 100%;padding: 8px;box-sizing: border-box;}.form-group button {width: 100%;padding: 10px;background-color: #5cb85c;color: white;border: none;cursor: pointer;}.error {color: red;text-align: center;}</style>
</head>
<body><div class="container"><h2>Login</h2><form method="POST" action="/login"><div class="form-group"><label for="username">Username</label><input type="text" id="username" name="username" required></div><div class="form-group"><label for="password">Password</label><input type="password" id="password" name="password" required></div>{% if error %}<p class="error">{{ error }}</p>{% endif %}<div class="form-group"><button type="submit">Login</button></div></form></div>
</body>
</html>

后端应用：

from flask import Flask, render_template, request, redirect, url_for, flash, sessionapp = Flask(__name__)
app.secret_key = 'your_secret_key'  # 用于会话加密，可以换成自己的密钥# 假设的用户数据，实际应用应从数据库中获取
users = {'admin': '123456','ma': 'nong'
}@app.route('/')
def index():if 'username' in session:return f'Logged in as {session["username"]}. <a href="/logout">Logout</a>'return redirect(url_for('login'))@app.route('/login', methods=['GET', 'POST'])
def login():if request.method == 'POST':username = request.form['username']password = request.form['password']# 检查用户名和密码if username in users and users[username] == password:session['username'] = usernamereturn redirect(url_for('index'))else:error = 'Invalid username or password.'return render_template('login.html', error=error)return render_template('login.html')@app.route('/logout')
def logout():session.pop('username', None)return redirect(url_for('login'))if __name__ == '__main__':app.run(debug=True)