It there any default asynchronious null context manager in python3.7+?

Question

I would like to create optional asynchronious semaphore.
In case of asyncio.Semaphore does not support None values, i decided to create asyncio.Semaphore, if connections limit is specified, else - some kind of dummy object
There is a contextlib.nullcontext, but it supports only synchorious with
I`ve created my own dummy:

@contextlib.asynccontextmanager
async def asyncnullcontext():
    yield None

It there any default asynchronious null context manager?

Answer 1

It there any default asynchronious null context manager?

You can use contextlib.AsyncExitStack().

ExitStack() was similarly the way to create a quick-and-dirty null context manager before the introduction of nullcontext.

Answer 2

Starting from Python 3.10+, contextlib.nullcontext() can be used as both a synchronous and asynchronous context manager.

from contextlib import nullcontext

def works():
    with nullcontext():
        pass

async def works_too():
    async with nullcontext():
        pass

(This question explicitly mentions Python 3.7 but I guess more and more people may find it without specifically needing that version, hence this answer)