python flask 入门 hello world

flask是小型的web 框架

flask 依赖于两个扩展库，Werkzeug和Jinja2。jinja2 渲染模版。Werkzeug是包含WSGI,标准的Python web应用程序的工具包。

hello world 程序

#!/usr/bin/Python
# -*- coding: utf-8 -*
from flask import Flask
from flask import request
from flask import make_response

# 创建flask对象
app = Flask(__name__)
# 定义路由使用app.route修饰期
@app.route('/')
def hello_world():
    return 'Hello World!'
# url中包含动态片段
@app.route('/user/<name>')
def user(name):
    return '<h1>Hello, %s!</h1>' % name
# flask 请求上下文request
@app.route('/useragent')
def index():
    user_agent = request.headers.get('User-Agent')
    return '<p>Your browser is %s</p>' % user_agent
# 响应的第二个参数是状态码，
@app.route('/badrequest')
def bad_request():
    return '<h1>Bad Request</h1>', 400
# response 设置cookie的值
@app.route('/response')
def response():
    response = make_response('<h1>This document carries a cookie!</h1>')
    response.set_cookie('answer', '42')
    return response

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