基于python3.5+的web框架sanic中文入门教程

简介

sanic是一款用python3.5+写的web framework，用法和flask类似，sanic的特点是非常快
github官网：https://github.com/channelcat...

速度比较

框架	实现基础	每秒请求数	平均时间
Sanic	Python 3.5 + uvloop	30,601	3.23ms
Wheezy	gunicorn + meinheld	20,244	4.94ms
Falcon	gunicorn + meinheld	18,972	5.27ms
Bottle	gunicorn + meinheld	13,596	7.36ms
Flask	gunicorn + meinheld	4,988	20.08ms
Kyoukai	Python 3.5 + uvloop	3,889	27.44ms
Aiohttp	Python 3.5 + uvloop	2,979	33.42ms

安装

环境：python3.5+
python -m pip install sanic

Hello World

创建文件main.py，写入下面的内容

from sanic import Sanic
from sanic.response import json

app = Sanic(__name__)

@app.route("/")
async def test(request):
    return json({ "hello": "world" })

app.run(host="0.0.0.0", port=8000)

运行python3 main.py
sanic是不是看起来和flask一样

　Request

属性
request.files (dictionary of File objects) - 上传文件列表
request.json (any) - json数据
request.args (dict) - get数据
request.form (dict) - post表单数据

例子

from sanic import Sanic
from sanic.response import json

@app.route("/json")
def post_json(request):
    return json({ "received": True, "message": request.json })

@app.route("/form")
def post_json(request):
    return json({ "received": True, "form_data": request.form, "test": request.form.get('test') })

@app.route("/files")
def post_json(request):
    test_file = request.files.get('test')

    file_parameters = {
        'body': test_file.body,
        'name': test_file.name,
        'type': test_file.type,
    }

    return json({ "received": True, "file_names": request.files.keys(), "test_file_parameters": file_parameters })

@app.route("/query_string")
def query_string(request):
    return json({ "parsed": True, "args": request.args, "url": request.url, "query_string": request.query_string })

　路由

和flask差不多，一看就懂

from sanic import Sanic
from sanic.response import text

@app.route('/tag/<tag>')
async def person_handler(request, tag):
    return text('Tag - {}'.format(tag))

@app.route('/number/<integer_arg:int>')
async def person_handler(request, integer_arg):
    return text('Integer - {}'.format(integer_arg))

@app.route('/number/<number_arg:number>')
async def person_handler(request, number_arg):
    return text('Number - {}'.format(number))

@app.route('/person/<name:[A-z]>')
async def person_handler(request, name):
    return text('Person - {}'.format(name))

@app.route('/folder/<folder_id:[A-z0-9]{0,4}>')
async def folder_handler(request, folder_id):
    return text('Folder - {}'.format(folder_id))

注册中间件

app = Sanic(__name__)

@app.middleware
async def halt_request(request):
    print("I am a spy")

@app.middleware('request')
async def halt_request(request):
    return text('I halted the request')

@app.middleware('response')
async def halt_response(request, response):
    return text('I halted the response')

@app.route('/')
async def handler(request):
    return text('I would like to speak now please')

app.run(host="0.0.0.0", port=8000)

异常处理

抛出异常

from sanic import Sanic
from sanic.exceptions import ServerError

@app.route('/killme')
def i_am_ready_to_die(request):
    raise ServerError("Something bad happened")

处理异常

from sanic import Sanic
from sanic.response import text
from sanic.exceptions import NotFound
@app.exception(NotFound)
def ignore_404s(request, exception):
    return text("Yep, I totally found the page: {}".format(request.url))

蓝图

和flask中的蓝图一样，用于组织项目结构
创建一个蓝图，相当于创建一个sanic app,上面的用法和上面相同，把app改成蓝图名称bp

from sanic.response import json
from sanic import Blueprint

bp = Blueprint('my_blueprint')

@bp.route('/')
async def bp_root():
    return json({'my': 'blueprint'})

蓝图注册到主app

from sanic import Sanic
from my_blueprint import bp

app = Sanic(__name__)
app.register_blueprint(bp)

app.run(host='0.0.0.0', port=8000, debug=True)

总结

sanic将是一个非常流行的框架．因为它基于python3.5+，使用了许多新的特性，这些特性让程序速度更快．