aio_pydispatch

Asyncio pydispatch (Signal Manager)

This is based on pyDispatcher reference Django Signals and reference scrapy SignalManager implementation on Asyncio

Event or Signal (not python bif signal)

You can bind multiple listeners (called sender) to listening multiple handlers (called receiver) on one event (called signal).

Default, the listener is None, so when the event is fire with no listener, all handlers will be executed that was bind default listener.

Usage

Most of the program has start and stop events, we can register some handler to events, we can also specify a sender.

import asyncio

from aio_pydispatch import Signal

server_start = Signal()
server_stop = Signal()


def ppp(value: str, **kwargs) -> None:
    print(value, kwargs)


async def main():
    server_start.connect(ppp, sender='loading config')
    server_stop.connect(ppp)
    await server_start.send(sender='loading config', value='foo')
    await asyncio.sleep(1)
    await server_stop.send(value='foo')


if __name__ == '__main__':
    asyncio.run(main())

Similar design

sync:

• pyDispatcher
• Django.dispatch
• scrapy SignalManager
• blinker

async:

• Aiohttp tracing

Others

Event system in Python