snacks 0.3.5

Wrapper to pika for an easy to use RabbitMQ interface.

Snacks

Snacks is a wrapper around pika to provide a convenient interface for RabbitMQ.

Installation

Snacks is available on PyPI and can be installed with:

pip install snacks

Configuration

from snacks.rabbit import RabbitClient

# These are all the default values if none are provided.
rabbit = RabbitClient(
    host='localhost',
    port=5672,
    default_exchange='',
    virtual_host='/',
    username='guest',
    password='guest'
)

Consume From Queues

To decorate a function as a consumer for a queue use the consumer decorator.

@rabbit.consumer('queue.name')
def listen(event: str) -> None:
    print(f'Received request: {event}')

Consume From Generated Queues

To decorate a function as a consumer for a generated queue using given routing keys use the listener decorator.

@rabbit.listener('routing_key')
def listen(event: str) -> None:
    print(f'Received request: {event}')

RPC

To make a decorated function a remote procedure add a return.

@rabbit.listener('routing_key')
def listen(event: str) -> str:
    print(f'Received request: {event}')
    return 'Remote response.'

Type Hint Based Deserialization

If the request body in a decorated function has type hints, snacks will try to map the received data to that type. This has added support for Dataclasses JSON or any other class with a from_json method.

@dataclass_json
@dataclass
class Event:
    type: str
    data: Any


@rabbit.listener('routing_key')
def user_event(event: Event) -> None:
    print(f'Received {event.type} with data {event.data}')

Full Example

from snacks.rabbit import RabbitClient

# Setup
rabbit = RabbitClient(default_exchange='snacks')
queue = 'snacks'
key = 'snackey'
rabbit.exchange_declare(exchange_type='topic', durable=True)
rabbit.queue_declare(queue=queue, durable=True)
rabbit.queue_bind(queue=queue, routing_key=key)


@rabbit.consumer([queue])
def listen(event: str) -> str:
    print(f'Received request: {event}')
    return 'Rabbits and pikas are snacks.'


if __name__ == '__main__':
    r = rabbit.publish_and_receive(
        'To a python.', key, deserialize=bytes.decode
    )
    print(f'Received response: {r}')

Output:

Received request: To a python.
Received response: Rabbits and pikas are snacks.