基於python3.5+的web框架sanic中文入門教程

Prasanta發表於2016-10-17
PythonWeb框架

簡介

sanic是一款用python3.5+寫的web framework，用法和flask類似，sanic的特點是非常快
github官網：https://github.com/channelcat...

速度比較

框架 實現基礎 每秒請求數 平均時間
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

安裝

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

Hello World

建立檔案main.py，寫入下面的內容

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)

執行python3 main.py
sanic是不是看起來和flask一樣

　Request

屬性
request.files (dictionary of File objects) - 上傳檔案列表
request.json (any) - json資料
request.args (dict) - get資料
request.form (dict) - post表單資料

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))

註冊中介軟體

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)

異常處理

丟擲異常

from sanic import Sanic
from sanic.exceptions import ServerError

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

處理異常

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))

藍圖

和flask中的藍圖一樣，用於組織專案結構
建立一個藍圖，相當於建立一個sanic app,上面的用法和上面相同，把app改成藍圖名稱bp

from sanic.response import json
from sanic import Blueprint

bp = Blueprint('my_blueprint')

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

藍圖註冊到主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)

總結

sanic將是一個非常流行的框架．因為它基於python3.5+，使用了許多新的特性，這些特性讓程式速度更快．

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