Python Flask基础到登录功能的实现代码_Python

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

Python Flask基础到登录功能的实现代码

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

Python Flask基础到登录功能的实现代码

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

Python Flask基础到登录功能的实现代码

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

Python Flask基础到登录功能的实现代码

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

Python Flask基础到登录功能的实现代码

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>