inspectisawaitable

inspect.isawaitable is a function in Python’s standard library (the inspect module) that determines whether a given object can be used in an await expression. It was introduced as part of the asyncio integration in Python 3.5 and remains a common helper when writing dynamic or generic asynchronous code.

Behavior and semantics: isawaitable(obj) returns True if obj is a coroutine object or if it defines an __await__ method, which makes it compatible with the await expression. This includes coroutine objects created by async def functions, as well as objects like asyncio.Future or asyncio.Task that implement the asynchronous protocol. If no such protocol exists, the function returns False.

Usage: The function is used to probe an object before awaiting it, or to adapt code paths based on awaitability. Typical usage is: from inspect import isawaitable; if isawaitable(x): result = await x else: result = x. This helps in writing flexible APIs that can handle both synchronous and asynchronous inputs, though it should not replace proper flow control in all cases.

Limitations: isawaitable is a best-effort check and does not guarantee that awaiting the object will succeed, nor does it account for runtime state changes. Relying on the test to decide whether to await can introduce race conditions in some asynchronous scenarios. In general, it is better to structure code so that awaiting is the intended path when possible.

See also: Python asyncio, coroutine, Future, __await__ protocol, asyncio.isfuture, asyncio.iscoroutine.