Python Web框架Flask下网站开发入门实例
2018-09-22 15:32
一、Flask简介
Flask 是一个 Python 实现的 Web 开发微框架。官网:
二、Demo
1、代码结构
复制代码 代码如下:
.
├── 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
复制代码 代码如下:
#!/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():
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():
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)
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
复制代码 代码如下:
<!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
复制代码 代码如下:
<!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
复制代码 代码如下:
<!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
复制代码 代码如下:
<!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