flask 模拟简单的登录功能(1)

模拟简单的登录功能

首先，在app.py中定义路由，用户访问根路径时，渲染 login.html 页面。输入用户名密码点击提交后，判断用户名密码是否正确，正确则提示登录成功，否则将报错信息显示在页面上

from flask import Flask,redirect,url_for,request,render_template
app = Flask(__name__)

# 根路径
@app.route('/')
def index():
    return render_template('login.html')

# 登录成功
@app.route('/success/<name>')
def success(name):
    return f'welcome {name}!<a href = "/">点击重新登录</a>'

# 直接访问 http://localhost:5000/login ，或者点击提交登录信息后的处理逻辑
@app.route('/login',methods=['POST','GET'])
def login():
    error = None
    if request.method == 'POST':
        user = request.form['username']
        if request.form['username'] != 'admin' or request.form['password'] != 'admin':
            error = '用户名或密码错误，请重试！'
        else:
            print(user)
            return redirect(url_for('success',name = user))
    return render_template('login.html',error = error)

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

login.html 页面入下：

<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Login</title>
</head>
<body>
    <form action="http://localhost:5000/login" method="post">
        <table>
            <tr>
                <td>Username</td>
                <td><input type="username" name="username"></td>
            </tr>
            <tr>
                <td>Password</td>
                <td><input type="password" name="password"></td>
            </tr>
            <tr>
                <td><input type="submit" value="Submit"></td>
            </tr>
        </table>
    </form>
    {% if error %}
    <p><strong>Error</strong>:{{error}}</p>
    {% endif %}
</body>
</html>