Welcome to subpub

subpub provides a minimalistic, thread-safe, publish-subscribe API for single-process Python applications.

• The latest documentation is available on Read the Docs.

• The source code is available on GitHub.

Example

The example below demonstrates basic usage.

# Create an instance of the message broker
>>> from subpub import SubPub
>>> sp = SubPub()

# Subscribe to a topic (= any string or regular expression).
# The returned queue `q` is used to retrieve published data:
>>> q = sp.subscribe(r'/food/(\w+)/order-(\d+)')

# Publish any data to topic:
>>> sp.publish('/food/pizza/order-66', "beef pepperoni")
True

# Get the published data from the queue:
>>> match, data = q.get()
>>> data
'beef pepperoni'

# The queue always receives the regexp `match` object as well.
# It can be used to see how the topic matched and get groups:
>>> match.groups()
('pizza', '66')

# Get the published topic:
>>> match.string
'/food/pizza/order-66'

See test cases in test_subpub.py for more examples.

Key features

• SubPub’s methods subscribe, unsubscribe, unsubscribe_all and publish are thread-safe.

• Subscribers use regular experssions to filter on topic.

• Subscribers receive published data through queues. (There is no built-in mechanism to register callbacks.)

• When an queue is garbage collected, unsubscribe is executed automatically (because SubPub only keeps a weak reference to the subscribers’ queues).

• Publishers can post any Python object as message.

• Publishers can use retain=True to store a message (as in MQTT).

Installation

From PyPI:

$ python3 -m pip install subpub

Reference

See module reference at Read the Docs.