Flask 框架基础知识笔记

2022-12-28 14:50:28 浏览数 (1)

Flask 基础

◆CheckBox 复选框◆

HTML index.html

代码语言:javascript复制
<body>
    <form action="/" method="post">
        <div class="MyDiv">
            <label>
                <input type="checkbox" name="s_option" value="basketball" > 篮球
            </label>
            <label>
                <input type="checkbox" name="s_option" value="football" > 足球
            </label>
            <label>
                <input type="checkbox" name="s_option" value="badminton" > 羽毛球
            </label>
        </div>
        <input type="submit" value="发送"/>
    </form>
</body>
</html>

后台 app.py

代码语言:javascript复制
from flask import Flask,render_template,request

app = Flask(__name__)

@app.route("/",methods=['POST','GET'])
def index():
    if request.method == "POST":
        data = request.values.getlist("s_option")
        print("您的选择内容是: %s" �ta)
    return render_template("index.html")

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

◆Select 选择框◆

HTML index.html

代码语言:javascript复制
<body>
    <form action="/" method="post">
        <select name="MySelect">
                 <option selected="selected">--请选择厂家--</option>
                 <option >惠普</option>
                 <option >华为</option>
                 <option >戴尔</option>
        </select>
        <input type="submit" value="发送"/>
    </form>
</body>

后台 app.py

代码语言:javascript复制
from flask import Flask,render_template,request

app = Flask(__name__)

@app.route("/",methods=['POST','GET'])
def index():
    if request.method == "POST":
        data = request.values.get("MySelect")
        print("您的选择内容是: %s" �ta)
    return render_template("index.html")

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

Ajax 发送数据◆

HTML页面发送数据,后端接收并返回数据

HTML index.html

代码语言:javascript复制
<body>
    <input type="button" class="MyButton" value="发送数据" onclick="SendAjax()">

    <script src="https://code.jquery.com/jquery-3.4.1.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        function SendAjax(){
            $.ajax({
                url:"/dataFromAjax",
                contentType: "POST",
                data:{"MyData": "hello lyshark"},
                success:function(data){
                    alert("返回数据:"   data);
                },
                error:function(){
                    alert("执行失败了...")
                }
            });
        }
    </script>
</body>

后台 app.py

代码语言:javascript复制
from flask import Flask,render_template,request
from flask import jsonify

app = Flask(__name__)

@app.route("/")
def index():
    return render_template("index.html")

@app.route("/dataFromAjax")
def recv():
    data = request.args.get("MyData")
    print("收到客户端数据: %s"�ta)
    return "通信成功..."

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

Ajax 获取数据◆

后端发送JSON数据,HTML页面接收数据并显示出来.

HTML index.html

代码语言:javascript复制
<body>
    <input type="button" class="MyButton" value="接收数据" onclick="GetAjax()">

    <script src="https://code.jquery.com/jquery-3.4.1.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        function GetAjax(){
            $.ajax({
                url:"/dataFromAjax",
                contentType: "GET",
                success:function(data){
                    alert("姓名: "   data.name   "年龄: "   data.age);
                },
                error:function(){
                    alert("执行失败了...")
                }
            });
        }
    </script>
</body>

后台 app.py

代码语言:javascript复制
from flask import Flask,render_template,request
from flask import jsonify

app = Flask(__name__)

@app.route("/")
def index():
    return render_template("index.html")

@app.route("/dataFromAjax",methods=["GET","POST"])
def set():
    data = {"name":"lyshark","age":"23"}
    return jsonify(data)

	# info = dict()    //另一种组装发送数据的方法
	# info['name'] = "lyshark"
	# info['age'] = 22
	# return jsonify(info)

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

Flask 过滤器

字符串操作:

代码语言:javascript复制
{# 当变量未定义时,显示默认字符串,可以缩写为d #}
<p>{{ name | default('No name', true) }}</p>
 
{# 单词首字母大写 #}
<p>{{ 'hello' | capitalize }}</p>
 
{# 单词全小写 #}
<p>{{ 'XML' | lower }}</p>
 
{# 去除字符串前后的空白字符 #}
<p>{{ '  hello  ' | trim }}</p>
 
{# 字符串反转,返回"olleh" #}
<p>{{ 'hello' | reverse }}</p>
 
{# 格式化输出,返回"Number is 2" #}
<p>{{ '%s is %d' | format("Number", 2) }}</p>
 
{# 关闭HTML自动转义 #}
<p>{{ '<em>name</em>' | safe }}</p>
 
{% autoescape false %}
{# HTML转义,即使autoescape关了也转义,可以缩写为e #}
<p>{{ '<em>name</em>' | escape }}</p>
{% endautoescape %}
#用管道的形式,如果avatar(后端传过来的变量)的值不存在,则用default的值
{{ avatar|default('xxx') }}    
#这里的意思为获取avatar的长度,avatar为后端传过来的变量,可以是列表,也可以是字典
{{ avatar|length }}

数值操作:

代码语言:javascript复制
{# 四舍五入取整,返回13.0 #}
<p>{{ 12.8888 | round }}</p>

{# 向下截取到小数点后2位,返回12.88 #}
<p>{{ 12.8888 | round(2, 'floor') }}</p>

{# 绝对值,返回12 #}
<p>{{ -12 | abs }}</p>

列表操作:

代码语言:javascript复制
{# 取第一个元素 #}
<p>{{ [1,2,3,4,5] | first }}</p>
 
{# 取最后一个元素 #}
<p>{{ [1,2,3,4,5] | last }}</p>
 
{# 返回列表长度,可以写为count #}
<p>{{ [1,2,3,4,5] | length }}</p>
 
{# 列表求和 #}
<p>{{ [1,2,3,4,5] | sum }}</p>
 
{# 列表排序,默认为升序 #}
<p>{{ [3,2,1,5,4] | sort }}</p>
 
{# 合并为字符串,返回"1 | 2 | 3 | 4 | 5" #}
<p>{{ [1,2,3,4,5] | join(' | ') }}</p>
 
{# 列表中所有元素都全大写。这里可以用upper,lower,但capitalize无效 #}
<p>{{ ['tom','bob','ada'] | upper }}</p>

字典列表操作:

代码语言:javascript复制
{% set users=[{'name':'Tom','gender':'M','age':20},
              {'name':'John','gender':'M','age':18},
              {'name':'Mary','gender':'F','age':24},
              {'name':'Bob','gender':'M','age':31},
              {'name':'Lisa','gender':'F','age':19}]
%}
 
 
 
{# 按指定字段排序,这里设reverse为true使其按降序排 #}
<ul>
{% for user in users | sort(attribute='age', reverse=true) %}
     <li>{{ user.name }}, {{ user.age }}</li>
{% endfor %}
</ul>
 
{# 列表分组,每组是一个子列表,组名就是分组项的值 #}
<ul>
{% for group in users|groupby('gender') %}
    <li>{{ group.grouper }}<ul>
    {% for user in group.list %}
        <li>{{ user.name }}</li>
    {% endfor %}</ul></li>
{% endfor %}
</ul>
 
{# 取字典中的某一项组成列表,再将其连接起来 #}
<p>{{ users | map(attribute='name') | join(', ') }}</p>

内置过滤器: tojson配合js使用,注意这里要避免HTML自动转义,所以加上safe过滤器

代码语言:javascript复制
<script type="text/javascript">
var users = {{ users | tojson | safe }};
console.log(users[0].name);
</script>

自定义过滤器: 自定义过滤器其实就是一个函数,自己写即可

代码语言:javascript复制
def mylen(arg):#实现一个可以求长度的函数
    return len(arg)

# 该函数实现给定一个区间返回区间的内容
def interval(test_str, start, end):#过滤器中传递多个参数,第一个参数为被过滤的内容,第二第三个参数需要自己传入
    return test_str[int(start):int(end)]

env = app.jinja_env
env.filters['mylen'] = mylen      #注册自定义过滤器
env.filters['interval'] = interval   #注册自定义过滤器

@app.route("/") 
def index(): 
  test_str = "hello" 
  return render_template("index.html", test_str=test_str)
#--------------------------------------------------------------------
jinja2模板
<body>
    <h1>len: {{test_str|mylen}}</h1>
    <h1>interval: {{test_str|interval(0,2)}}</h1>    #test_str作为参数传到interval函数里
</body>

Flask 简单应用

简单的参数传递: 通过配置不同的路由路径,接受不同的参数,最后返回给用户.

代码语言:javascript复制
from flask import Flask,render_template,request

app = Flask(__name__)

@app.route("/post/id=<id>")                       # 参数需要放在"<>"中,并且要与函数中传入的参数同名
def post(id):                                     # 加入参数,函数名称要与上面的路由名称相同
    return "请求的参数是 %s" %id

@app.route("/post/user=<name>&pass=<pasd>")       # 可同时传递多个参数,中间的&可有可无
def user(name,pasd):
    return "用户名: %s 密码: %s" %(name,pasd)

if __name__ == '__main__':
    app.run(host="0.0.0.0",port="80",debug=True)

URL地址跳转 当输入正确用户名密码后,自动跳转到成功的页面上.

代码语言:javascript复制
from flask import Flask,render_template,request
from flask import url_for,redirect

app = Flask(__name__)
@app.route("/")
def index():
    return "<b> 这是首页,请先登录.. </b>"

@app.route("/post/id=<username>")
def Check(username):
    if username == "admim":
        return "用户%s登录完成了.." %username
    else:
        return redirect(url_for("login"))    #失败,跳转到登陆函数(界面)

@app.route("/login/")
def login():
    return "<b> 请登陆... </b>"

if __name__ == '__main__':
    app.run(host="0.0.0.0",port="80",debug=True)

◆URL反向解析◆

反转url主要用于模版和页面的重定向(从视图函数到url的转换)

代码语言:javascript复制
from flask import Flask,render_template,request
from flask import url_for

app = Flask(__name__)

@app.route("/")
def index():
    print(url_for("post",id="lyshark"))
    return "/"

@app.route("/post/<id>")
def post(id):
    return "<h1> hello %s </h1>" %id

if __name__ == '__main__':
    app.run(host="0.0.0.0",port="80",debug=True)

◆简单的参数传递◆

HTML index.html

代码语言:javascript复制
<body>
    <p>第一个flask页面</p>
    <p>姓名:{{ username }}</p>
    <p>height:{{ height }}</p>
</body>

后台 app.py

代码语言:javascript复制
from flask import Flask,url_for,redirect,render_template

app = Flask(__name__)

@app.route("/")
def index():
    info = {
        "username":"lyshark",
        "gender":"man",
        "height":"165"
    }

    #如果有多个参数,可以将所有的参数放到字典中,然后以**kwargs的方式传递进去,info为上面定义的字典
    #这里直接写模版文件名称,如果在模版文件在temlate/html目录下,则这里需要写'html/index.html'
    return render_template("index.html",**info)  

    #渲染模版,传参数,如果参数较少,可以直接写关键字参数及值,如下:
  #return render_template('index.html',username='name',gender="man",height="178")

if __name__ == '__main__':
    app.run(host="0.0.0.0",port="80",debug=True)

◆复杂的参数传递◆

HTML index.html

代码语言:javascript复制
<body>
    <p>第一个flask页面</p>
    <p>姓名:{{ username }}</p>
    <p>height:{{ height }}</p>
    <hr>
    <p>{{ person.name }}---{{ person.age }}</p>  //此处对应上面py中定义的Person类
    <p>{{ city.bj }}</p>               //第一种取值方式
    <p>{{ city['tj'] }}</p>                       //第二种取值方式
</body>

后台 app.py

代码语言:javascript复制
from flask import Flask,url_for,redirect,render_template
 
app = Flask(__name__)
 
@app.route('/')
def index():
    class Person(object):
        name='tttt'
        age=18
 
    p = Person()
    info = {
        'username' :'name',
        'gender':"man",
        'height' : "178",
        'person':p,
        'city':{
            'bj':"bj",
            'tj':'tj'
        }
 
    }
    return render_template('index.html',**info)
    #return render_template('index.html',username='name',gender="man",height="178")
 
if __name__ == '__main__':
    app.run(debug=True)

◆自定义错误页◆

代码语言:javascript复制
@app.errorhandler(404)
def page_noe_found(error):
    return render_template('home/404.html'),404

@app.errorhandler(500)
def page_noe_found(error):
    return render_template('home/500.html'),500

◆IF语句的使用◆

HTML: index.html

代码语言:javascript复制
<body>
    {% if users and users.age >10 %}        #这里的users为py文件里传递的user字典,users.age为py文件user字典里的age
        <a href="#">{{ users.aa }}</a>
        <a href="#">{{  users.bbb}}</a>
    {% else %}
        <a href="#">登陆</a>
        <a href="#">注册</a>
    {% endif %}
</body>

后台: app.py

代码语言:javascript复制
from flask import Flask,url_for,redirect,render_template

app = Flask(__name__)

@app.route('/<is_login>')
def index(is_login):

    if is_login == "1":        #模拟1为登陆成功
        user = {
            "aa":"test",
            'bbb':'注销',
            'age':"11"
        }
        return render_template('index.html',users=user)
    else:
        return render_template('index.html')


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

◆FOR语句的使用◆

HTML: index.html

代码语言:javascript复制
<body>
    {% for k,v in user.items() %}        #for语句
        <p>{{ k }}----{{ v }}</p>
    {% endfor %}
</body>

后台: app.py

代码语言:javascript复制
from flask import Flask,url_for,redirect,render_template

app = Flask(__name__)

@app.route('/')
def index():
    users = {
        'username':'tsdf',
        'age':11
    }
    return render_template('index.html',user=users)

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

◆钩子函数的使用◆

before_request函数,就是一个装饰器,他可以把需要设置为钩子函数的代码放到视图函数执行之前执行.

代码语言:javascript复制
from flask import Flask,url_for,redirect,render_template,request
app = Flask(__name__)

@app.route('/')
def index():
    print ('index')
    return 'index'

@app.before_request
def mybefore_request():
    print ('before_request')

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

Flask 常用开发片段

实现记住密码功能: 在不使用框架的情况下,手撸登录验证功能.

前端HTML页面

代码语言:javascript复制
<script src="http://libs.baidu.com/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
  $(document).ready(function(){
        var strName = localStorage.getItem('keyName');
        var strPass = localStorage.getItem('keyPass');
        if(strName){
            $('#user').val(strName);
        }if(strPass){
            $('#pass').val(strPass);
        }
        if(strName!=null && strPass!=null)
            $('#remember').attr("checked",true);
    });
    function login_click(){
            var strName = $('#user').val();
            var strPass = $('#pass').val();
            if($('#remember').is(':checked')){
                localStorage.setItem('keyName',strName);
                localStorage.setItem('keyPass',strPass);
            }else{
                localStorage.removeItem('keyName',strName);
                localStorage.removeItem('keyPass');
            }
            window.location.reload();
        }
</script>

<body>
    <form action="/" method="post" onsubmit="return login_click();">
        账号: <input type="text" id="user" placeholder="用户名" name="username" /><br><br>
        密码: <input type="password" id="pass" placeholder="密码" name="password" /><br><br>
        记住密码: <input type="checkbox" id="remember">
        <input type="submit" value="用户登录"/>
    </form>
    <div>
        {% if flag == 1 %}
            <p>当前登录用户: {{ user }} 该用户密码是: {{ pasd }}</p>
        {% elif flag == 0 %}
            <p>登录失败了,你输入的密码有误.</p>
        {% endif %}
    </div>
</body>

后台代码

代码语言:javascript复制
from flask import Flask,render_template,request
import re

app = Flask(__name__)
@app.route("/",methods=['GET','POST'])
def index():
    if request.method == "GET":
        return render_template("index.html")
    elif request.method == "POST":
        username = request.form.get("username")
        password =request.form.get("password")
        if username != "" and password != "":                            # 用户名密码不能为空
            if re.findall(r"[a-zA-Z0-9]{4,15}$", username):              # 用户名不能含有特殊字符
                if re.findall(r"[a-zA-Z0-9]{5,15}$", password):          # 密码必须符合安全要求
                    if username == "admin" and password == "admin123":
                        print("收到用户名: %s --->收到密码: %s" % (username, password))
                        return render_template("index.html", flag=1,user=username, pasd=password)
                    else:
                        return render_template("index.html", flag=0)
                else:
                    return '''<script type="text/javascript">alert('错误,密码开头必须为字母!');</script>'''
            else:
                return '''<script type="text/javascript">alert('错误,用户名存在特殊字符,或长度不符!');</script>'''
        else:
            return '''<script type="text/javascript">alert('您不能输入空的用户名或密码!');</script>'''

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

选择框使用技巧: 单选框,复选框,多选框等.

前端代码

代码语言:javascript复制
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
    <title>页面选择</title>

</head>
<body>
<form method="post">
    <p>{{ form.gender.label }} {{form.gender}} {{form.gender.errors[0] }}</p>
    <p>{{ form.city.label }} {{form.city}} {{form.city.errors[0] }} </p>
    <p>{{ form.hobby.label }} {{form.hobby}} {{form.hobby.errors[0] }}</p>
    <p>{{ form.favor.label }} {{form.favor}} {{form.favor.errors[0] }}</p>
    <input type="submit" value="提交表格">
</form>
</body>
</html>

后台代码

代码语言:javascript复制
from flask import Flask, render_template, request, redirect
from wtforms import Form,validators,widgets
from wtforms.fields import simple,html5,core

app = Flask(__name__,template_folder="templates")

class RegisterForm(Form):
    gender = core.RadioField(
        label="性别:",choices=((0,"男"),(1,"女"),(0,"两面派")),coerce=int  #限制是int类型的
    )
    city = core.SelectField(
        label="选择城市:",
        choices=(
            ("shandong","山东省"),("shanghai","上海市"),
            ("beijingshi","北京市"),("neimenggu","内蒙古")
        ),
        render_kw={'class': 'btn btn-primary dropdown-toggle'}
    )
    hobby = core.SelectMultipleField(
        label='爱好:',
        choices=((1, '唱'),(2, '跳'),(3,'rap'),(4,'篮球')),
        coerce=int,
        render_kw = {'class': 'form-control'}
    )
    favor = core.SelectMultipleField(
        label="特长:",
        choices=((1, 'Python把妹'),(2, '渗透把妹'),(3,"运维把妹"),(4,"科学把妹")),
        widget = widgets.ListWidget(prefix_label=False),
        option_widget = widgets.CheckboxInput(),
        coerce = int, default = [1, 2 , 4],
    )

@app.route('/submit',methods=["GET","POST"])
def submit():
    if request.method=="GET":
        form = RegisterForm(data={'gender': 1}) # 指定性别的默认值是1
        return render_template("submit.html",form=form)
    else:
        form = RegisterForm(formdata=request.form)
        if form.validate():
            print('提交的值为:', form.data)
            return '''<script type="text/javascript">alert('您的请求已提交!');</script>'''
        else:
            print("提交数据错误..")
        return render_template('submit.html', form=form)

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

◆实现文件上传◆

HTML: upload.html

代码语言:javascript复制
<script type="text/javascript">
    function CheckFileType(filename)
    {
        var flag = false;
        var arry = ["bmp","jpg"];
        var index = filename.lastIndexOf(".");
        var ext = filename.substr(index 1);
        for(var i=0;i<arry.length;i  )
        {
            if(ext == arry[i])
            {
                flag=true;
                break;
            }
        }
        if(!flag){alert('错误,文件名后缀不合法!');}
    }
</script>

<body>
    <form action="/upload" enctype="multipart/form-data" method="post">
        <input type="file" name="file" onchange="CheckFileType(this.value)">
        <input type="submit" value="上传文件">
    </form>
    <p style="color: green">状态: {{ file_flage }}</p>
</body>

后台: app.py

代码语言:javascript复制
from flask import Flask,render_template,request
import os,uuid

app = Flask(__name__)
app.config['MAX_CONTENT_LENGTH'] = 3000000   # 限制文件上传最大为3MB

@app.route("/upload",methods=['GET','POST'])
def upload_file():
    if request.method == "GET":
        return render_template("upload.html")
    elif request.method == "POST":
        file = request.files["file"]
        filename = str(file.filename)
        if len(filename) >= 20:          # 限制文件名的长度必须在20个字符以内
            return render_template("upload.html",file_flage="文件名长度超出了限制!")
        else:
            if filename.find(".") >= 0:  # 查找文件中是否包含点这个字符
                filetype = file.filename.split(".")[1]     # 取出文件类型,后期做判断
                if filetype != None and filetype == "bmp": # 后缀格式必须是bmp结尾
                    uid = uuid.uuid4()                     # 生成随机名称
                    save_file_name = str(uid)   "."   filetype  # 拼接名称
                    file.save(save_file_name)                   # 保存文件
                    return render_template("upload.html",file_flage="文件上传成功 {}".format(save_file_name))
            else:
                return render_template("upload.html",file_flage="没有选择文件,或不是图片格式,上传失败!")
    return render_template("upload.html",file_flage="文件上传失败,未知错误!")

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

实现文件下载

代码语言:javascript复制
<script type="text/javascript">
    function Download(filename)
    {
        if(filename){window.location.href='/download/?path='   filename}
    }
</script>
<body>
    <form action="/download" enctype="multipart/form-data" method="get">
        <input type="text" name="down" onchange="Download(this.value)"/>
        <input type="submit" value="下载文件" >
    </form>
</body>
代码语言:javascript复制
from flask import Flask, render_template, request, Response
app = Flask(__name__)

@app.route('/download/', methods=['GET', 'POST'])
def download_file():
    if request.method == 'GET':
        args = request.args.get("path").replace("/","").replace("\","")
        args = args.replace("<>","").replace("<!--","")
        args = "./templates/"   args
        print("下载的文件: {}".format(args))
        def send_file():
            store_path = args
            with open(store_path, 'rb') as targetfile:
                while 1:
                    data = targetfile.read(10 * 1024 * 1024)   # 每次读取10M
                    if not data:
                        break
                    yield data
        response = Response(send_file(), content_type='application/octet-stream')
        response.headers["Content-disposition"] = 'attachment; filename=%s'%args.split("/")[2]  # 取出下载的名字
        return response

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

实现前端组合数据,后端接受

代码语言:javascript复制
<body>
    <script src="https://code.jquery.com/jquery-3.4.1.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        function SendAjax(){
            var username = $('input[name="username"]').val();
            var password = $('input[name="password"]').val();
            var json = {"username":username,"password":password};
            $.ajax({
                url:"/dataFromAjax",
                contentType: "POST",
                data:json,
                success:function(data){
                    if(data=="1"){alert("请求已经提交.");}
                },
                error:function(){
                     //alert("执行失败了...")
                }
            });
        }
    </script>

    <form action="/dataFromAjax" method="post">
        用户账号: <input type="text" placeholder="用户账号" name="username" /><br><br>
        用户密码: <input type="text" placeholder="用户密码" name="password" /><br><br>
        <input type="button" value="发送数据" onclick="SendAjax()">
    </form>
</body>
代码语言:javascript复制
from flask import Flask,render_template,request
from flask import jsonify

app = Flask(__name__)

@app.route("/")
def index():
    return render_template("index.html")

@app.route("/dataFromAjax",methods=['GET'])
def recv():
    username = request.args.get("username")
    password = request.args.get("password")
    if(username=="" or password ==""):
        return "0"
    else:
        print("收到客户{} 密码 {} ".format(username,password))
        return "1"

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

◆实现Session◆

代码语言:javascript复制
from flask import Flask,render_template,request
from flask import session,url_for,escape,redirect
import os

app = Flask(__name__)

@app.route('/')
def index():                               #自动验证session
    if 'username' in session:
        return '用户 %s 已经登陆成功...' % escape(session['username'])
    return '您还没有登陆呢...'


@app.route('/login', methods=['GET', 'POST'])
def login():                                 #登陆session
    if request.method == 'POST':
        session['username'] = request.form['username']
        return redirect(url_for('index'))
    return '''
        <form action="" method="post">
            <p><input type=text name=username>
            <p><input type=submit value=登陆>
        </form>
    '''
@app.route('/get')
def get():                                   #获取session
    return "用户: %s" %session.get('username')

@app.route('/logout')
def logout():                                #注销session
    session.pop('username', None)
    # session.clear()                #清空session里的所有数据
    return redirect(url_for('index'))

app.secret_key = os.urandom(24)             #加盐,服务端每次重启都会变化
if __name__ == '__main__':
    app.run()

◆表格结构遍历◆

HTML index.html

代码语言:javascript复制
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<body>
    <form action="/" method="post">
        <input type="text" placeholder="姓名" name="username" />
        <input type="text" placeholder="性别" name="usersex" />
        <input type="text" placeholder="邮箱" name="email" />
        <input type="text" placeholder="手机号" name="phone" />
        <input type="text" placeholder="留言内容" name="usertext" />
        <input type="submit" value="点我提交表单"/>
    </form>
    <br>
     <table border="1" class="table table-hover">
            <thead>
            <th>用户IP</th> <th>用户姓名</th> <th>性别</th> <th>邮箱</th> <th>手机号</th><th>留言</th>
            </thead>
            <tbody>
                {% for temp in user %}
                    <tr>
                        <td>{{ temp.userip }}</td>
                        <td>{{ temp.username }}</td>
                        <td>{{ temp.usersex }}</td>
                        <td>{{ temp.email }}</td>
                        <td>{{ temp.phone }}</td>
                        <td>{{ temp.usertext }}</td>
                    </tr>
                {% endfor %}
            </tbody>
        </table>
</body>

后台: app.py

代码语言:javascript复制
from flask import Flask,render_template,request
import json

app = Flask(__name__)
temp = [ ]

@app.route("/",methods=['GET','POST'])
def index():
    if request.method == "GET":
        return render_template("index.html", user=temp)
    elif request.method == "POST":
        userip = str(request.remote_addr)
        username = request.form.get("username")
        usersex = request.form.get("usersex")
        email = request.form.get("email")
        phone = request.form.get("phone")
        usertext = request.form.get("usertext")
        if username != "" and usertext != "" and usersex != "" and email != "":
            data = {"userip":userip,"username":username,"usersex":usersex,"email":email,"phone":phone,"usertext":usertext}
            temp.append(data)                       #追加数据到列表
            with open("data.json", "w", encoding="UTF-8") as f:
                s = json.dump(temp, f, ensure_ascii=False)
            return render_template("index.html",user=temp)
        return  render_template("index.html",user=temp)

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

模态对话框的使用: 后台接收参数,与上方相同,区别在于使用BootCSS弹框.

代码语言:javascript复制
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>弹出式编辑框</title>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
    <script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
</head>
<body>
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal" data-whatever="@mdo">编辑主机</button>
    <div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
      <div class="modal-dialog" role="document">
        <div class="modal-content">
          <div class="modal-header">
            <h5 class="modal-title" id="exampleModalLabel">编辑运维主机</h5>
            <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                <span aria-hidden="true">X</span>
            </button>
          </div>

          <!--主体框架,使用form表单提交-->
          <div class="modal-body" >
            <form action="/edit" method="post">
              <!--按钮主体框架-->
              <div class="form-group">
                <label class="form-inline" for="recipient-name" class="col-form-label">主机名称:</label>
                <input type="text" class="form-control" id="recipient-name" name="hostname">
              </div>
              <div class="form-group">
                <label class="form-inline" for="recipient-name" class="col-form-label">IP地址:</label>
                <input type="text" class="form-control" id="recipient-name" name="ipaddress">
              </div>
                <!--关闭事件,此处只有两个按钮-->
              <div style="display: block;text-align: center;" class="modal-footer">
                <button type="button" class="btn btn-secondary" data-dismiss="modal">关闭窗口</button>
                <button type="submit" class="btn btn-primary">提交数据</button>
              </div>
           </form>
        </div>
      </div>
    </div>
</div>
</body>
</html>

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