twingly-pyamqp 0.1.2

A Python implementation for subscribing and publishing messages via RabbitMQ.

Twingly::PYAMQP

A Python implementation of the twingly-amqp gem for subscribing and publishing messages via RabbitMQ.

Usage

Environment variables:

• RABBITMQ_N_HOST - Defaults to localhost
• AMQP_USERNAME - Defaults to guest
• AMQP_PASSWORD - Defaults to guest

Docs

AMQPconfig

Used to configure RabbitMQ host, port, user, and password. Arguments take precedence over environment variables and should only be used to override environment or default values, since env variables and default values are used if no AMQPconfig is provided.

Arguments

• rabbitmq_host
• rabbitmq_port
• amqp_user
• amqp_password

AMQP Connection

Exchange options match Kombu Exchange Arguments, similarly, queue options match those defined in Kombu Queue Arguments.

Arguments

Constructor

Argument	Type	Default	Description
config	AMQPconfig | None	None	Optional AMQPconfig to override RabbitMQ connection. Defaults to using environment variables.

Methods

declare_queue

Argument	Type	Default	Description
queue_name	str	No	The name of the queue to declare.
exchange_name	str | None	None	The name of the exchange the queue is bound to. If None, uses the default exchange.
routing_key	str | None	None	The routing key for the queue. If None, defaults to queue_name.
exchange_opts	dict | None	None	Optional dictionary of options to configure the exchange.
queue_opts	dict | None	None	Optional dictionary of options to configure the queue.

Raises ValueError if a routing key is set without specifying an exchange.

declare_exchange

Argument	Type	Default	Description
exchange_name	str	No	The name of the exchange to declare.
exchange_opts	dict | None	None	Optional dictionary of options for the exchange.

Example Usage

# Establish an AMQP connection
connection = AmqpConnection()

# Declare an exchange
connection.declare_exchange("logs")

# Declare an exchange with optional options
connection.declare_exchange("logs", exchange_opts={"type": "topic", "durable": False})

# Declare a queue on default exchange
connection.declare_queue(queue_name="task_queue")

# Declare a queue and bind to exchange and routing key
connection.declare_queue(
    queue_name="task_queue",
    exchange_name="logs",
    routing_key="task_key",
    queue_opts={"max_length": 1000}
)

---

Publisher

Arguments

Constructor

Argument	Type	Default	Description
exchange_name	str | None	None	The name of the exchange to route the messages to. Leave empty to publish to default exchange.
routing_key	str | None	None	The routing key used for directing the message.
config	AMQPconfig | None	None	Optional override configuration for AMQP connection settings.
publish_args	dict | None	None	Additional arguments that match the publish method arguments of Kombu's Producer.

Methods

publish

Argument	Type	Default	Description
payload	object	No	The message to publish to the exchange.
routing_key	str | None	None	Optionally override the default routing key.

Raises ValueError if no routing key is provided at instantiation or publication time.

Example Usage

# Create an instance of Publisher with default values
publisher = Publisher()

# Create an instance of Publisher with a specific routing key
publisher = Publisher(exchange_name="custom_exchange", routing_key="custom_routing_key")

# Publish messages
publisher.publish({"message": "hello, RabbitMQ"})  # Uses the routing key specified at instantiation
publisher.publish({"message": "hello, RabbitMQ"}, routing_key="override_routing_key") # Overrides routing key

# Publish message with additional arguments
publisher.publish({"message": "hello, RabbitMQ"}, publish_args={"priority": 7})

---

Subscription

Arguments

Constructor

Argument	Type	Default	Description
queue_names	str | list[str]	No	The name of the queue(s) to subscribe to. Accepts a single name or a list.
config	AMQPconfig | None	None	Optional override configuration for AMQP connection settings.

Methods

subscribe

Argument	Type	Default	Description
callbacks	Callable[[str, object], None] | list[Callable[[str, object], None]]	No	The function(s) to process incoming messages.
blocking	bool	True	If True, blocks the main thread while consuming messages.
timeout	int | None	None	Maximum time (in seconds) to wait for messages. Required if blocking=False.
max_connect_attempt	int	3	Maximum number of retries for establishing a connection.
consumer_args	dict | None	None	Additional arguments that match Kombu's Consumer arguments.

Raises ValueError if blocking=False and no timeout is provided. Raises ValueError if a subscription is already active.

cancel

Argument	Type	Default	Description
None	-	-	Cancels the active subscription and stops consuming messages.

Example Usage

# Create an instance of Subscription for a single queue
subscription = Subscription(queue_names="task_queue")

# Create an instance of Subscription for multiple queues
subscription = Subscription(queue_names=["queue1", "queue2"])

# Subscribe to messages in blocking mode
subscription.subscribe(callback=Callable[[str, object], None])

# Subscribe to messages in non-blocking mode with a timeout
subscription.subscribe(callback=Callable[[str, object], None], blocking=False, timeout=5,consumer_args={"no_ack": True, "prefetch_count": 5})

# Cancel the subscription
subscription.cancel()