CODEWITHSUNDEEP
pythonpython-asyncio
Bob Fang
Bob Fang

Reputation: 7381

Is await just a syntatic sugar for create_task in Python Asyncio?

Hi given this example below:

enter image description here

My question is that if the await statement is just a syntactic sugar, for example

c = await <coro>()

is actually equivalent to

_c = asyncio.create_task(<coro>())
c = _c.result

under the hood?

Upvotes: 0

Views: 441

Answers (1)

alex_noname
alex_noname

Reputation: 32073

They are not equivalent.

await

result = await awaitable_object

suspends the coroutine until the awaitable_object is done, then returns it’s result, or raises an exception, which will be propagated. There are three main types of awaitable objects: coroutines, Tasks, and Futures. await expression are only valid within an async def and, simply put, runs a coroutine or task synchronously.

create_task

asyncio.create_task(coro, *, name=None) Wrap the coro coroutine into a Task and schedule its execution soon. Return the Task object. It does not suspend the execution of the current code and does not return the result of the task. create_task can be called both within async def coroutines and ordinary def functions.

Simply put, create_task does not execute the task immediately, does not wait its result, but only schedules its execution in the near future.

Task.result()

Return the result of the Task. If the Task is done, the result of the wrapped coroutine is returned (or if the coroutine raised an exception, that exception is re-raised.) If the Task’s result isn’t yet available, this method raises a InvalidStateError exception.

Upvotes: 2

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