async-object 1.0.0rc0

async-object let you write classes with async def __init__.

async-object

async-object let you write classes with async def __init__

Usage

It is simple, with async-object you can do this :

from async_object import AsyncObject


class MyObject(AsyncObject):
    async def __new__(cls) -> "MyObject":
        self = await super().__new__(cls)

        # Do some async stuff

        return self

    async def __init__(self) -> None:
        await super().__init__()

        # Do some async stuff


if __name__ == "__main__":
    import asyncio

    async def main() -> None:
        instance = await MyObject()
        assert isinstance(instance, MyObject)

    asyncio.run(main())

Abstract base classes

import abc

from async_object import AsyncObject, AsyncABCMeta


class MyAbstractObject(AsyncObject, metaclass=AsyncABCMeta):
    @abc.abstractmethod
    def method(self) -> None:
        raise NotImplementedError

    @abc.abstractmethod
    async def async_method(self) -> None:
        raise NotImplementedError


class MyObject(MyAbstractObject):
    async def __init__(self, arg1: int, arg2: str) -> None:
        await super().__init__()

    def method(self) -> None:
        pass

    async def async_method(self) -> None:
        pass

Troubleshoots

Static type checking

Static type checker like mypy does not like having async def for __new__ and __init__. You can use # type: ignore[misc] comment to mask these errors when overriding these methods.

class MyObject(AsyncObject):
    async def __new__(cls) -> "MyObject":  # type: ignore[misc]
        return await super().__new__(cls)

    async def __init__(self) -> None:  # type: ignore[misc]
        await super().__init__()