python - 有没有办法让 asyncio.create_task 返回异步函数之外的值？

Question

我需要从异步函数之外的 asyncio.create_task(function()) 返回一个值。

import asyncio

async def hello():
    return("hello")

response = asyncio.get_event_loop().create_task(hello())
print(response)

这是输出的内容:

<Task pending coro=<hello() running at C:\Users\\PycharmProjects\PCWebsite\fjdfjd.py:3>>

当我想收到:

"Hello"

请注意，我不能使用 .run()

RuntimeError: asyncio.run() cannot be called from a running event loop

或 run_until_complete 当我收到错误时

RuntimeError: This event loop is already running

Answer 1

根据asyncio.create_task记录函数返回 Task目的。

asyncio.create_task(coro, *, name=None)

Wrap the coro coroutine into a Task and schedule its execution. Return the Task object.

您可以使用 Task通过调用函数 task.result() 从任务本身提取结果(和一些其他信息)的函数当结果准备好时(任务完成)。

例子:

import asyncio

async def func1():
    return 1233

loop = asyncio.get_event_loop()
task = loop.create_task(func1())
# The following line is needed so the loop will run and complete the task in the first place.
loop.run_until_complete(task)

结果与:

>>> task.done()
True
>>> task.result()
1233