Puka is yet-another Python client library for RabbitMQ. But as opposed to similar libraries, it does not try to expose a generic AMQP API. Instead, it takes an opinionated view on how the user should interact with RabbitMQ.
Puka exposes a simple, easy to understand API. Take a look at the
import puka client = puka.Client("amqp://localhost/") promise = client.connect() client.wait(promise) promise = client.queue_declare(queue='test') client.wait(promise) promise = client.basic_publish(exchange='', routing_key='test', body='Hello world!') client.wait(promise)
Puka is fully asynchronous. Although, as you can see in example above, it can behave synchronously. That's especially useful for simple tasks when you don't want to introduce callbacks.
Here's the same code written in an asynchronous way:
import puka def on_connection(promise, result): client.queue_declare(queue='test', callback=on_queue_declare) def on_queue_declare(promise, result): client.basic_publish(exchange='', routing_key='test', body="Hello world!", callback=on_basic_publish) def on_basic_publish(promise, result): print " [*] Message sent" client.loop_break() client = puka.Client("amqp://localhost/") client.connect(callback=on_connection) client.loop()
You can mix synchronous and asynchronous programming styles if you want to.
In the pure asynchronous programming style Puka never blocks your
program waiting for network. However it is your responsibility to
notify when new data is available on the network socket. To allow that
Puka allows you to access the raw socket descriptor. With that in hand
you can construct your own event loop. Here's an the event loop that
wait_for_any from previous example:
fd = client.fileno() while True: client.run_any_callbacks() r, w, e = select.select([fd], [fd] if client.needs_write() else , [fd]) if r or e: client.on_read() if w: client.on_write()
Puka is asynchronous and has no trouble in handling many requests at a time. This can be exploited to achieve a degree of parallelism. For example, this snippet creates 1000 queues in parallel:
promises = [client.queue_declare(queue='a%04i' % i) for i in range(1000)] for promise in promises: client.wait(promise)
Puka also has a nicely optimized AMQP codec, but don't expect miracles
- it can't go faster than Python.
Puka does expose only a sensible subset of AMQP, as judged by the author.
The major differences between Puka and normal AMQP libraries include:
- Puka doesn't expose AMQP channels to the users.
- Puka treats
basic_publishas a synchronous method. You can wait on it and make sure that your data is delivered. Alternatively, you may ignore the promise and treat it as an asynchronous command.
- Puka tries to cope with the AMQP exceptions and expose them to the user in a predictable way. Unlike other libraries it's possible (and recommended!) to recover from AMQP errors.
Puka is a side project, written mostly to prove if it is possible to create a reasonable API on top of the AMQP protocol.
The best examples to start with are in the rabbitmq-tutorials repo.
More code can be found in the
./examples directory. Some
./examples/send.py: sends one message
./examples/receive_one.py: receives one message
./examples/stress_amqp_consume.py: a script used to benchmark the throughput of the server
There is also a bunch of fairly complicated examples hidden in the
tests (see the
Puka works with Python 2.6 and 2.7.
You can install Puka system-wide using pip:
sudo pip install puka
Alternatively to install it in the
virtualenv local environment:
virtualenv my_venv pip -E my_venv install puka
Or if you need the code from trunk:
sudo pip install -e git+http://github.com/majek/puka.git#egg=puka
Great. Make sure you have
rabbitmq server installed and follow this
git clone https://github.com/majek/puka.git cd puka make cd examples
Now you're ready to run the examples, start with:
The easiest way to get started is to take a look at the examples and tweak them to your needs. Detailed documentation doesn't exist now. If it existed it would live here: