Why Sanic Beats Flask: Speed Benchmarks, Setup, and Advanced Features

Speed Comparison

Sanic      Python 3.5 + uvloop   30,601 req/s   3.23 ms
Wheezy     gunicorn + meinheld   20,244 req/s   4.94 ms
Falcon     gunicorn + meinheld   18,972 req/s   5.27 ms
Bottle     gunicorn + meinheld   13,596 req/s   7.36 ms
Flask      gunicorn + meinheld    4,988 req/s  20.08 ms
Kyoukai    Python 3.5 + uvloop    3,889 req/s  27.44 ms
Aiohttp    Python 3.5 + uvloop    2,979 req/s  33.42 ms

Installation

python -m pip install sanic

Hello World

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)

Running

python3 main.py

Request Object

Attributes

request.files – dictionary of uploaded File objects

request.json – JSON payload

request.args – query string parameters

request.form – POST form data

Request Handling Examples

from sanic import Sanic
from sanic.response import json

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

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

@app.route("/files")
async def upload_file(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": list(request.files.keys()), "test_file_parameters": file_parameters})

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

Routing

from sanic import Sanic
from sanic.response import text

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

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

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

Middleware Registration

app = Sanic(__name__)

@app.middleware('request')
async def request_middleware(request):
    print("I am a spy")
    # optionally return a response to halt the request
    # return text('I halted the request')

@app.middleware('response')
async def response_middleware(request, response):
    # modify response if needed
    return response

Exception Handling

from sanic import Sanic
from sanic.exceptions import ServerError, NotFound
from sanic.response import text

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

@app.exception(NotFound)
def ignore_404s(request, exception):
    return text(f"Yep, I totally found the page: {request.url}")

Blueprints

from sanic import Blueprint, Sanic
from sanic.response import json

bp = Blueprint('my_blueprint')

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

app = Sanic(__name__)
app.register_blueprint(bp)
app.run(host='0.0.0.0', port=8000, debug=True)

Conclusion

Sanic is expected to become a popular framework because it leverages Python 3.5+ features that make applications run faster.