当前位置 博文首页 > Python Flask基础到登录功能的实现代码

    Python Flask基础到登录功能的实现代码

    作者:Scr1pt_kid 时间:2021-06-08 18:16

    视频教程教学地址:https://www.bilibili.com/video/BV18441117Hd?p=1

    0x01路由

    from flask import Flask
    
    app = Flask(__name__)  # flask对象实例化
     
    @app.route('/index')    #定义首页
    @app.route('/')       #设置默认index
    def index():
        return 'hello world!'
    
    @app.route('/home/<string:username>')   # 生成home路由,单一传参
    def home(username):
        print(username)
        return '<h1>欢迎回家</h1>'
    
    @app.route('/main/<string:username>/<string:password>') #多个参数传递
    def main(username,password):
        print(username)
        print(password)
        return '<h1>welcome</h1>'
    
    def about():
        return  'about page'
    app.add_url_rule(rule='/about',view_func=about)  #另一种添加路由的方式
    
    if __name__ == '__main__':
        app.debug = True  #开启debug模式
        app.run()

    0x02 模版和静态文件

    2.1 文件结构

    在这里插入图片描述

    2.2代码

    #app.py
    #app.py
    from flask import Flask,render_template    #倒入模版
    
    app = Flask(__name__) #声明模版文件夹
    
    
    @app.route(('/index'))
    def index():
    
      return render_template('index.html') #返回模版
    
    if __name__ == '__main__':
        app.run(debug=True)
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
        <h1>hello hello</h1>
        <img src="/static/imgs/1.png">
    </body>
    </html>

    2.3 运行效果

    在这里插入图片描述

    0x03 json

    from flask import Flask,jsonify
    
    app = Flask(__name__)
    
    @app.route('/')
    def index():
        user = {'name':'李三','password':'123'}
        return jsonify(user)
    
    if __name__ == '__main__':
        app.run(debug=True)

    3.1运行效果

    在这里插入图片描述

    0x04 重定向

    4.1 访问跳转

    from flask import Flask, redirect  #导入跳转模块
    
    app = Flask(__name__)
    
    @app.route('/index')
    def index():
        return redirect('https://www.baidu.com') #指定跳转路径,访问/index目录即跳到百度首页
    
    @app.route('/home')
    def home():
        return 'home page'
    if __name__ == '__main__':
        app.run(debug=True)

    4.2 打印路由

    from flask import Flask,url_for #导入模块
    
    app = Flask(__name__)
    
    @app.route('/index')
    def index():
        return 'test'
    
    @app.route('/home')
    def home():
        print(url_for('index'))   打印 index路由
        return 'home page'
    
    if __name__ == '__main__':
        app.run(debug=True)
    

    4.3 跳转传参

    # 访问home,将name带入index并显示在页面
    from flask import Flask,url_for,redirect #导入模块
    
    app = Flask(__name__)
    
    @app.route('/index<string:name>')
    def index(name):
        return 'test %s' % name
    
    @app.route('/home')
    def home():
        return redirect(url_for('index',name='admin'))
    
    if __name__ == '__main__':
        app.run(debug=True)

    0x05 jinjia2模版

     5.1代码

    from flask import Flask,render_template    #倒入模版
    
    app = Flask(__name__) #声明模版文件夹
    
    
    @app.route(('/index'))
    def index():
        user = 'admin'
        data = ['111',2,'李三']
        userinfo = {'username':'lisan','password':'12333'}
        return render_template('index.html',user=user,data=data,userinfo=userinfo) #返回模版,传入数据
    
    if __name__ == '__main__':
        app.run(debug=True)
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
      <h1>11111</h1>
    
      {{user}}
      {{data}}   #直接传入
    
      {% if user == 'admin'%}   #简单逻辑判断
        <h1 style="color:red">管理员</h1>
      {% else %}
        <h1 style="color:green">普通用户</h1>
      {% endif %}
      <hr>
    
      {% for item in data %}   # for循环
        <li>{{item}}</li>
      {% endfor %}
    
      <hr>
      {{ userinfo['username'] }}   
      {{ userinfo['password'] }}
    
      <hr>
      {{ user | upper }}   #字母大写(更多可查阅jinjia2过滤器)
    </body>
    </html>

    5.2 运行效果

    在这里插入图片描述

    0x06 蓝图

    目的是为了更好的细分功能模块

    6.1代码结构

    ├── admin
    │   └── admin.py
    └── app.py

    6.2 代码

    #admin.py
    from flask import Blueprint  导入蓝图模块
    
    admin = Blueprint('admin',__name__,url_prefix='/admin') #对象实例化,url_prefix添加路由前缀,表示若想访问本页相关路由,只能通过形如 xxx/admin/login 访问,不能 xxx/login访问
    
    @admin.route('/register')
    def register():
        return '欢迎注册'
    
    @admin.route('/login')
    def login():
         return '欢迎登录'
    #app.py
    from flask import Flask
    from admin.admin import admin as admin_blueprint   # 导入蓝图
    
    
    app = Flask(__name__) #声明模版文件夹
    app.register_blueprint(admin_blueprint)  #注册蓝图
    
    @app.route(('/index'))
    def index():
        return 'index page'
    
    if __name__ == '__main__':
        app.run(debug=True)

    0x07 登录

     7.1结构

    在这里插入图片描述

    7.2代码

    #web.py
    from flask import Flask,render_template,request,redirect,flash,url_for,session
    from os import urandom
    app = Flask(__name__)
    app.config['SECRET_KEY'] = urandom(50)
    @app.route('/index')
    def index():
        if not session.get('user'):
                flash('请登录后操作','warning')
                return redirect(url_for('login'))
        return render_template('index.html')
    
    @app.route('/login',methods=['GET','POST'])
    def login():
        if request.method == 'GET':
            return  render_template('login.html')
        elif request.method == 'POST':
            username = request.form.get('username')
            password = request.form.get('password')
    
            if username == 'admin' and password == '888888':
                flash('登录成功','success')
                session['user'] = 'admin'
                return redirect(url_for('index'))
            else:
                flash('登录失败','danger')
                return  redirect(url_for('login'))
    
    if __name__ == '__main__':
        app.run(debug=True)
    # index.html
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css" rel="external nofollow"  rel="external nofollow"  integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
    
    <!-- 最新的 Bootstrap 核心 JavaScript 文件 -->
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js" integrity="sha384-aJ21OjlMXNL5UyIl/XNwTMqvzeRMZH2w8c5cRVpzpU8Y5bApTppSuUkhZXN0VxHd" crossorigin="anonymous"></script>
    
    </head>
    <body>
        <h1>欢迎你,管理员</h1>
         {% for color, message in get_flashed_messages(with_categories=True) %}
         <div class="alert alert-{{color}} alert-dismissible" role="alert">
      <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <p>{{message}}</p>
    </div>
      {% endfor %}
    </body>
    </html>
    #login.html
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>login</title>
      <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css" rel="external nofollow"  rel="external nofollow"  integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
    
    <!-- 最新的 Bootstrap 核心 JavaScript 文件 -->
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js" integrity="sha384-aJ21OjlMXNL5UyIl/XNwTMqvzeRMZH2w8c5cRVpzpU8Y5bApTppSuUkhZXN0VxHd" crossorigin="anonymous"></script>
    </head>
    <body>
      <form action="/login" method="post">
        <div class='form-group'>
          <input type="text" name="username" placeholder="请输入用户名" class="form-control">
        </div>
        <div class='form-group'>
          <input type="password" name="password" placeholder="请输入密码" class="form-control">
        </div>
        <div class="form-group">
          <input type="submit" value= "submit" class="btn btn-primary">
        </div>
    
      </form>
    
          {% for color, message in get_flashed_messages(with_categories=True) %}
         <div class="alert alert-{{color}} alert-dismissible" role="alert">
      <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <p>{{message}}</p>
    </div>
      {% endfor %}
    </body>
    </html>

    7.3实现效果

    7.3.1未登录默认跳转到登录页面

    在这里插入图片描述

    7.3.2登录成功跳转到index页面

    账户密码:admin/888888

    在这里插入图片描述

    7.3.2登录失败效果

    在这里插入图片描述

    js