【python】web开发

No1：

hello.py

def application(environ,start_response):
    start_response(\'200 OK\',[(\'Content-Type\',\'text/html\')])
    return [b\'<h1>Hello,web!<h1>\']

server.py

from wsgiref.simple_server import make_server
from hello import application

httpd = make_server(\'\',8000,application)
print(\'Serving HTTP on port 8000..\')
httpd.serve_forever()

执行server.py后打开浏览器

无论多么复杂的Web应用程序，入口都是一个WSGI处理函数。HTTP请求的所有输入信息都可以通过environ获得，HTTP响应的输出都可以通过start_response()加上函数返回值作为Body。

No2：

【Flask】web框架

另外

Django：全能型Web框架；
web.py：一个小巧的Web框架；
Bottle：和Flask类似的Web框架；
Tornado：Facebook的开源异步Web框架。

from flask import Flask
from flask import request

app=Flask(__name__)

@app.route(\'/\',methods=[\'GET\',\'POST\'])
def home():
    return \'<h1>Home</h1>\'
    
@app.route(\'/signin\',methods=[\'GET\'])
def signin_form():
    return \'\'\'<form action="/signin" method="post">
              <p><input name="username"></p>
              <p><input name="password" type="password"></p>
              <p><button type="submit">Sign In</button></p>
              </form>\'\'\'
            
@app.route(\'/signin\',methods=[\'POST\'])
def signin():
    if request.form[\'username\']==\'admin\' and request.form[\'password\']==\'password\':
        return \'<h3>Hello,admin!</h3>\'
    return \'<h3>Bad username or password.</h3>\'
    
if __name__== \'__main__\':
    app.run()

注意：py文件命名的时候不要和框架重名

运行结果

No3：

【MVC】

from flask import Flask,request,render_template

app=Flask(__name__)

@app.route(\'/\',methods=[\'GET\',\'POST\'])
def home():
    return render_template(\'home.html\')
    
@app.route(\'/signin\',methods=[\'GET\'])
def signin_form():
    return render_template(\'form.html\')

@app.route(\'/signin\',methods=[\'POST\'])
def signin():
    username=request.form[\'username\']
    password=request.form[\'password\']
    if username==\'admin\' and password==\'password\':
        return render_template(\'signin-ok.html\',username=username)
    return render_template(\'form.html\',message=\'Bad usesrname or password\',username=username)
    
if __name__ == \'__main__\':
    app.run()

<html>
<head>
    <title>Home</title>
</head>
<body>
    <h1 style="font-style:italic">Home</h1>
</body>
</html>

<html>
<head>
    <title>Please Sign In</title>
</head>
<body>
    {% if message %}
    <p style="color:red">{{message}}</p>
    {% endif %}
    <form action="/signin" method="post">
        <legend>Please sign in:</legend>
        <p><input name="username" placeholder="Username" value="{{username}}"></p>
        <p><input name="password" placeholder="Password" type="password"></p>
        <p><button type="submit">Sign In</button></p>
    </from>
</body>
</html>

<html>
<head>
    <title>Welcome,{{username}}</title>
</head>
<body>
    <p>Welcome,{{username}}!</p>
</body>
</html>

运行结果

有了MVC，我们就分离了Python代码和HTML代码