python學習筆記十三：Flaskdemo

2019-11-14 17:25:59

字體：大中小

來源：轉載

供稿：網友

一、Flask簡介

Flask 是一個 Python 實現的 Web 開發微框架。官網：http://flask.pocoo.org/

二、Demo

1、代碼結構

.├── blog.py├── static│   ├── CSS│   │   └── index.css│   ├── images│   │   ├── cat.jpg│   │   └── sheying1229.jpg│   └── js└── templates    ├── index.html    ├── login.html    ├── regist.html    └── upload.html5 directories, 8 files

2、主程序blog.py

#!/usr/bin/python#coding:utf8from flask import Flask, render_template, url_for, request,redirect,make_response,sessionimport os,MySQLdbapp = Flask(__name__)app.secret_key='afjlsjfowflajflkajfkjfkaljf'user_list = ['jim','max','py']imagepath = os.path.join(os.getcwd(),"static/images")@app.route('/')def index():    username = request.cookies.get('username')    if not username:        username = u'請先登錄'    islogin = session.get('islogin')    nav_list = [u'首頁',u'經濟',u'文化',u'科技',u'娛樂']    blog = {'title':'welcome to my blog','content':'hello, welcome to my blog.'}    blogtag = {'javascript':10,"python":20,"shell":5}    img = url_for('static', filename="images/cat.jpg")    return render_template('index.html', nav_list=nav_list, username=username, blog = blog, blogtag = blogtag, img=img, islogin=islogin)@app.route('/reg', methods=['GET','POST'])def regist():    if request.method == 'POST':        username = request.form['username']        conn = MySQLdb.connect(user='root',passwd='admin',host='127.0.0.1')        conn.select_db('blog')        curr = conn.cursor()        sql = 'insert into `user` (`id`,`username`) values (%d,"%s")' % (1,username)        curr.execute(sql)        conn.commit()        curr.close()        conn.close()        return "user %s regist ok!" % request.form['username']    else:        #request.args['username']        return render_template('regist.html')@app.route('/upload', methods=['GET','POST'])def upload():    if request.method == 'POST':        username = request.form['username']        file = request.files['img']        filename = file.filename        file.save(os.path.join(imagepath,filename))        return "<img src='static/images/%s' alt=''/>" % filename    else:        return render_template('upload.html')@app.route('/login/', methods=['GET','POST'])def login():    if request.method == 'POST':        username = request.form.get('username')        if username in user_list:            response = make_response(redirect('/'))            response.set_cookie('username', value=username, max_age=300)            session['islogin'] = '1'            return response        else:            session['islogin'] = '0'            return redirect('/login/')    else:        return render_template('login.html')if __name__ == '__main__':    app.run(debug=True,host='0.0.0.0',port=5000)

主要有首頁、注冊、登錄、上傳頁面。

blog.py主要是展示了Flask中常見功能用法：路由，數據庫操作，cookie，session，redirect，表單，文件上傳，調試，Web服務器的IP和端口，靜態文件讀取等。

3、首頁模板index.html

<!DOCTYPE html><html><head>    <meta charset="utf-8"/>    <title>Flask DEMO</title>    <link rel="stylesheet" type="text/css" href="static/css/index.css"/></head><body>    <div class="header">        {%if islogin == '1' %}        <h1>Welcome ,{{username}}!</h1>        {%else%}        <h1>{{username}}!</h1>        {%endif%}        <div class="nav">            <ul>                {%for nav in nav_list%}                <li><a href="{{nav}}">{{nav}}</a></li>                {%endfor%}            </ul>        </div>    </div>    <div class="container">        <div class="item">            <h1>{{blog['title']}}</h1>            <div class="content">                <img src="/static/images/cat.jpg" alt="cat" />                <p>{{blog['content']}}</p>                <img src="{{img}}" alt="cat" />            </div>        </div>        <div class="side">            <ul>                {%for key,value in blogtag.items()%}                    <li>{{key}}({{value}})</li>                {%endfor%}            </ul>        </div>    </div></body></html>

這個模板主要展示了在Flask模板中如何讀取各種類型的變量。

4、登錄頁面login.html

<!DOCTYPE html><html><head>    <meta charset="utf-8"/>    <title>Login</title>    <link rel="stylesheet" type="text/css" href="static/css/index.css"/></head><body>    <div class="header">        <h1>Login</h1>    </div>    <div class="container">        <div class="item">            <form action="" method="post">                <input type="text" placeholder="please input username" name="username" /><br/>                <input type="submit" value="Login"/>            </form>        </div>    </div></body></html>

結合blog.py主要展示表單如何提交取值，cookie和session應用。

5、注冊頁面regist.html

<!DOCTYPE html><html><head>    <meta charset="utf-8"/>    <title>Regist</title>    <link rel="stylesheet" type="text/css" href="static/css/index.css"/></head><body>    <div class="header">        <h1>Regist</h1>    </div>    <div class="container">        <div class="item">            <form action="" method="post">                <input type="text" placeholder="please input username" name="username" /><br/>                <input type="submit" value="Regist"/>            </form>        </div>    </div></body></html>

結合blog.py主要展示了數據庫操作。

6、上傳頁面upload.html

<!DOCTYPE html><html><head>    <meta charset="utf-8"/>    <title>Upload</title>    <link rel="stylesheet" type="text/css" href="static/css/index.css"/></head><body>    <div class="header">        <h1>Upload</h1>    </div>    <div class="container">        <div class="item">            <form action="" method="post" enctype="multipart/form-data">                <input type="text" name="username" /><br/>                <input type="file" name="img" /><br/>                <input type="submit" value="Upload"/>            </form>        </div>    </div></body></html>