Responder

Responder – https://python-responder.org

Talk given at:

Django Friends – Vienna 20.11.2018.
https://www.meetup.com/Django-Vienna/events/246063480/

Transcript

1. Responder
   Dražen Lučanin
   
   @metakermit
   
   Django Friends – Vienna 20.11.2018.
   

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2. Hello, world!
   import responder
   api = responder.API()
   @api.route("/{greeting}")
   async def greet_world(req, resp, *, greeting):
   resp.text = f"{greeting}, world!"
   if __name__ == '__main__':
   api.run()
   

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3. Another Python web
   framework in 2018?
   • “A familiar HTTP Service Framework”
   
   • By Kenneth Reitz (Requests)
   
   • Kind of like an async Python web framework for humans
   
   • Not reinventing the wheel, but combining best practices
   
   • “Take Falcon, make it more like Flask & then give it some
   upgrades” – Kenneth Reitz @ Import This, Ep. 17
   

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4. • ASGI – async / await
   
   • f-string syntax routes
   
   • Built-in static file server
   
   • Single-page webapp support
   
   • Built-in Requests for tests
   
   • Meta-framework – mount any ASGI / WSGI app at a subroute
   
   • GraphQL support
   … some upgrades?
   

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5. Mostly built in one month
   • How?
   
   • #hacktoberfest2018
   
   • https://www.starlette.io/ by Tom Christie
   
   • Starlette is to Responder what Werkzeug is to Flask
   
   • So let’s go over Responder’s features…
   

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6. ASGI – async / await
   • Starlette – an ASGI implemented on top of uvicorn
   
   • async background tasks without Celery – no blocking
   import time
   @api.route("/incoming")
   async def receive_incoming(req, resp):
   @api.background.task
   def process_data(data):
   """Just sleeps for three seconds, as a demo."""
   time.sleep(3)
   # Parse the incoming data as form-encoded.
   # Note: 'json' and 'yaml' formats are also automatically supported.
   data = await req.media()
   # Process the data (in the background).
   process_data(data)
   # Immediately respond that upload was successful.
   resp.media = {'success': True}
   

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7. f-string syntax routes
   • The beloved Python 3 feature in action
   @api.route("/hello/{who}")
   def hello_to(req, resp, *, who):
   resp.text = f"hello, {who}!"
   

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8. Built-in static file server
   • Files from the static/ folder served using WhiteNoise
   
   • Single-page webapp support – all routes passed to index.html
   api.add_route("/", static=True)
   

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9. “What about an ORM?”
   – every Django developer
   • There are some solutions, but it’s still early days
   
   • GINO – https://github.com/fantix/gino
   
   • a lightweight asynchronous ORM built on top
   of SQLAlchemy core for Python asyncio
   
   • Peewee-async – https://peewee-async.readthedocs.io/
   
   • Responder comes with Marshmallow – https://
   marshmallow.readthedocs.io/ (a serialisation standard)
   

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10. Built-in Requests for tests
    import myapi
    @pytest.fixture
    def api():
    return myapi.api
    def test_response(api):
    hello = "hello, world!"
    @api.route('/some-url')
    def some_view(req, resp):
    resp.text = hello
    r = api.requests.get(url=api.url_for(some_view))
    assert r.text == hello
    

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11. How to start?
    • https://github.com/metakermit/responder-react
    
    • A simple Responder backend & React frontend starter kit
    
    • Using https://parceljs.org/ – a fast, 0-config web app bundler
    pip install -U cookiecutter
    cookiecutter gh:metakermit/responder-react
    cd helloresponderreact
    # local environment
    bin/install
    bin/start
    # docker environment
    docker-compose up
    

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12. Thanks!
    

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