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Python Flask基础到登录功能的实现代码

作者：Scr1pt_kid　　发布时间：2022-01-04 14:29:57　

标签：Python,Flask,登录

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

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

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

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

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

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">


<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">×</span></button>
<p>{{message}}</p>
</div>
{％ endfor ％}
</body>
</html>

#login.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>login</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">


<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">×</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

7.3.2登录成功跳转到index页面

账户密码：admin/888888

7.3.2登录失败效果

来源：https://blog.csdn.net/weixin_54430466/article/details/116651409

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