trio-future

概述

trio-future 允许您捕获并发执行的三io函数的返回值。它是一种与使用三io通道进行通信相比，更像使用常规函数进行编程的替代方案。

考虑以下简单的回声函数示例

async def echo(a: str) -> str:
    await trio.sleep(0.5)
    return a

我们可以调用我们的函数，并在我们准备好时返回其结果

async with trio.open_nursery() as nursery:
    # Call trio_future.run to synchronously get back a Future
    future = trio_future.run(nursery, echo, "hello")
    # When we call `await` and yield to scheduler, our function begins executing
    await trio.sleep(0.1)
    # We can `await` the function when we are ready
    hello = await future.get() 
    # hello == "hello"

一个常见的用例是并发运行多个任务，并等待它们全部完成。 trio-future 有一个类似于 asyncio.gather 的 gather 函数来完成此操作

async with trio.open_nursery() as nursery:
    fut_1 = run(nursery, echo, "hello")
    fut_2 = run(nursery, echo, "world")
    # Call `gather` to package the two Futures into a single Future object.
    # Note that this is again a synchronous function.
    joined_future = gather(nursery, [fut_1, fut_2])
    # Again, when we `await` the result, we yield to the scheduler. This time, both
    # of our futures will execute concurrently.
    hello_world = await join_future.get()
    # hello_world = ["hello", "world"]