Python 3.4+Async programmingfunction

asyncio.iscoroutine()

introspection

Checks whether an object is a coroutine object, i.e. the result of calling an async function rather than the function itself.

Syntax

asyncio.iscoroutine(obj)

A common mix-up: iscoroutine(fetch) is False while iscoroutine(fetch()) is True. Calling fetch() runs nothing, it only creates the object; if you neither await nor close it, Python emits RuntimeWarning "coroutine was never awaited". To test a function use inspect.iscoroutinefunction, and for "can I await this" use inspect.isawaitable: a Task or a Future is not a coroutine.

Examples

import asyncio
async def fetch():
    return 1
coro = fetch()
print(asyncio.iscoroutine(fetch))  # → False — это функция
print(asyncio.iscoroutine(coro))  # → True
coro.close()  # иначе RuntimeWarning: coroutine was never awaited

import asyncio
async def main():
    task = asyncio.create_task(asyncio.sleep(0.01))
    print(asyncio.iscoroutine(task))  # → False — задача awaitable, но не корутина
    await task
asyncio.run(main())

asyncio.iscoroutine()

Syntax

Examples

See also