Webservices

Build and consume web services (aka APIs) in Python.

Features

• Providers that work with Django, Flask and Twisted
• Everything is signed (using itsdangerous)
• Synchronous consumer (framework independant)
• Asynchronous consumer (powered by Twisted)

Installation

Django (provider/consumer)

pip install webservices[django]

Flask (provider/consumer)

pip install webservices[flask]

Twisted (provider/consumer)

pip install webservices[twisted]

Synchronous consumer only

pip install webservices[consumer]

Quickstart

We'll write an API that greets you with your name (or 'hello world' if not name is provided).

Provider

Django

We assume you have a setting API_KEYS which is a dictionary of public keys mapping to private keys.

myapi/urls.py:

from django.conf.urls import url, patterns
from webservices.sync import provider_for_django
from myapi.views import HelloProvider

urlpatterns = patterns('',
    url(r'hello/$', provider_for_django(HelloProvider())),
)

Your myapi/views.py:

from django.conf import settings
from webservices.models import Provider

class HelloProvider(Provider):
    def get_private_key(self, public_key):
        return settings.API_KEYS.get(public_key)

    def provide(self, data):
        name = data.get('name', 'world')
        return {'greeting': u'hello %s' % name}

Flask

app.py:

from flask import Flask
from webservices.sync import provider_for_flask
from webservices.models import Provider

app = Flask(__name__)

API_KEYS = {
    'publickey': 'privatekey', # your keys here
}

class HelloProvider(Provider):
    def get_private_key(self, public_key):
        return API_KEYS.get(public_key)

    def provide(self, data):
        name = data.get('name', 'world')
        return {'greeting': u'hello %s' % name}

provider_for_flask(app, '/hello/', HelloProvider())

Twisted

app.py:

from twisted.internet import reactor
from twisted.web.server import Site
from webservices.async import provider_for_twisted
from webservices.models import Provider

API_KEYS = {
    'publickey': 'privatekey', # your keys here
}

class HelloProvider(Provider):
    def get_private_key(self, public_key):
        return API_KEYS.get(public_key)

    def provide(self, data):
        name = data.get('name', 'world')
        return {'greeting': u'hello %s' % name}

resource = provider_for_twisted(HelloProvider())

site = Site(resource)
reactor.listenTCP(80, site)
reactor.run()

Noticed how the provider is basically the same for all three (other than get_private_key)? Neat, right?

Handling errors

To log errors (for example using raven) you can implement the report_exception method on Provider classes. This method is called whenever the provide method throws an exception. It takes no arguments.

Consumer

Synchronous

To consume that code (assuming it's hosted on 'https://api.example.org'):

from webservices.sync import SyncConsumer

consumer = SyncConsumer('https://api.example.org', 'mypublickey', 'myprivatekey')
result = consumer.consume('/hello/', {'name': 'webservices')
print result # prints 'hello webservices'

Asynchronous

Same as above, but async:

from webservices.async import TwistedConsumer
from twisted.internet import reactor

def callback(result):
    print result # prints 'hello webserivces'
    reactor.stop()

consumer = TwistedConsumer('https://api.example.org', 'mypublickey', 'myprivatekey')
deferred = consumer.consume('/hello/', {'name': 'webservices')
deferred.addCallback(callback)

reactor.run()

Data Source Name

You can create consumers from Data Source Names (eg 'http://public_key:private_key@api.example.org') using the from_dsn classmethod on consumers.

Example:

consumer = SyncConsumer.from_dsn('https://public_key:private_key@api.example.org')

License

This code is licensed under the 3-clause BSD license, see LICENSE.txt.