Generator based coroutines were long deprecated and removed andasyncio doesn't not supports it. There is some left over code for supporting it which can be removed now.

The first thing is this behavior ofasyncio.iscoroutine which makes no sense now. I propose to remove this first.

importasynciodefgen():yield1assertnotasyncio.iscoroutine(gen())# fails

Linked PRs

• GH-102748: remove legacy support for generator based coroutines fromasyncio.iscoroutine #102749