asyncio-paho 0.2.1

A Paho MQTT client supporting asyncio loop without additional setup.

Asynchronous I/O (asyncio) Paho MQTT client

A Paho MQTT client supporting asyncio loop without additional setup. Forget about configuring the Paho network-loop. The client can almost be used as a drop-in replacement for Paho Client. The asyncio loop is automatically configured when you connect.

Features

• Drop-in replacement of Paho Client (inherits from Paho Client)
• Automatic configuration of asyncio loop.
• Reconnect on connection loss.
• Type hinted.
• Async callbacks.
• Non blocking connect (await client.asyncio_connect()).
• Python Asynchronous Context Manager handles cleanup.
• No threading, only asyncio.

Installation

pip install asyncio-paho

Usage

You should use Paho connect_async() or extension asyncio_connect() when connecting to avoid blocking.

Drop-in replacement

Remove all you calls to Paho looping like loop_forever() etc.

client = AsyncioPahoClient()
client.connect_async("mqtt.eclipseprojects.io")

# remove your current looping (loop_forever() etc)
# do mqtt stuff

client.Disconnect()

Asynchronous Context Manager

The client is an Asynchronous Context Manager and can be used with the Python with statement to atomatically disconnect and clean up.

async with AsyncioPahoClient() as client:
    client.connect_async("mqtt.eclipseprojects.io")

    # do mqtt stuff - client.Disconnect() is called when exiting context.

Extensions

The client has some additional async features (functions prefixed with asyncio_).

asyncio_connect

The classic Paho connect() is blocking. Paho connect_async() is not blocking, but returns before the connect is complete. Use asyncio_connect() to wait for connect to complete without blocking. This function also throws exception on connect failure. Please not that asyncio_connect() cannot be used together with on_connect /on_connect_fail (use asyncio_add_on_connect_listener and asyncio_add_on_connect_fail_listener instead of on_connect and on_connect_fail).

async with AsyncioPahoClient() as client:
    await client.asyncio_connect("mqtt.eclipseprojects.io")

Callbacks

Paho has a lot of callbacks. Async alternatives have been added for some of them, but they are mutally exclusive (you have to pick sync or async for eatch callback type). Multiple async listeners can be added to the same event, and a function handle to unsubscribe is returned when adding.

Classic Paho	Extension alternative	Called when
on_connect	asyncio_add_on_connect_listener()	the broker responds to our connection
on_connect_fail	asyncio_add_on_connect_fail_listener()	the client failed to connect to the broker
on_message	asyncio_add_on_message_listener()	a message has been received on a topic that the client subscribes to
on_subscribe	asyncio_add_on_subscribe_listener()	the broker responds to a subscribe request

async def on_connect_async(client, userdata, message) -> None:
    client.subscribe("mytopic")

async with AsyncioPahoClient() as client:
    client.asyncio_add_on_connect_listener(on_connect_async)
    await client.asyncio_connect("mqtt.eclipseprojects.io")

Dependencies

• Python 3.8 or later.
• Paho MQTT

The client uses asyncio event loop add_reader() and add_writer() methods. These methods are not supported on Windows by ProactorEventLoop (default from Python 3.8). You should be able to use another event loop like SelectorEventLoop.