Python Web框架Flask下网站开发入门实例
一、Flask简介
Flask 是一个 Python 实现的 Web 开发微框架。官网：http://flask.pocoo.org/
二、Demo
1、代码结构
.
├── blog.py
├── static
│ ├── css
│ │ └── index.css
│ ├── images
│ │ ├── cat.jpg
│ │ └── sheying1229.jpg
│ └── js
└── templates
├── index.html
├── login.html
├── regist.html
└── upload.html
5 directories, 8 files
2、主程序blog.py
#!/usr/bin/python
#coding:utf8
from flask import Flask, render_template, url_for, request,redirect,make_response,session
import os,MySQLdb
app = 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'请先登录'
islogin = session.get('islogin')
nav_list = [u'首页',u'经济',u'文化',u'科技',u'娱乐']
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)
主要有首页、注册、登录、上传页面。
blog.py主要是展示了Flask中常见功能用法：路由，数据库操作，cookie，session，redirect，表单，文件上传，调试，Web服务器的IP和端口，静态文件读取等。
3、首页模板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>
这个模板主要展示了在Flask模板中如何读取各种类型的变量。
4、登录页面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>
结合blog.py主要展示表单如何提交取值，cookie和session应用。
5、注册页面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>
结合blog.py主要展示了数据库操作。
6、上传页面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>
结合blog.py主要展示了如何上传文件。
7、运行效果
