Typed asynchronous signal for Python. A few lines of code will do the trick, no need to install another aiosignals.

signals.py

import asyncio
from typing import Callable, Coroutine, MutableSequence, ParamSpec

P = ParamSpec("P")
R = Coroutine[None, None, None]


class AsyncSignal(MutableSequence[Callable[P, R]]):
    def __init__(self, *iterable: Callable[P, R]) -> None:
        self.callbacks = list(iterable)

    def __len__(self) -> int:
        return len(self.callbacks)

    def __getitem__(self, index: int) -> Callable[P, R]:
        return self.callbacks[index]

    def __setitem__(self, index: int, value: Callable[P, R]) -> None:
        self.callbacks[index] = value

    def __delitem__(self, index: int) -> None:
        del self.callbacks[index]

    def insert(self, index: int, value: Callable[P, R]) -> None:
        self.callbacks.insert(index, value)

    def connect(self, callback: Callable[P, R]) -> None:
        self.callbacks.append(callback)

    def disconnect(self, callback: Callable[P, R]) -> None:
        self.callbacks.remove(callback)

    async def send(self, *args: P.args, **kwargs: P.kwargs) -> None:
        async with asyncio.TaskGroup() as tg:
            for callback in self.callbacks:
                task = tg.create_task(callback(*args, **kwargs))
                task.add_done_callback(lambda _: task.result())  # raise exception