运行时错误：await 未与 python3.8 中的 future - 异步字典理解一起使用

Question

我已经完成了关于异步列表理解的本教程。现在我想尝试异步字典理解。这是要复制的代码：

import asyncio


async def div7_tuple(x):
    return x, x/7


async def main():
    lost = [4, 8, 15, 16, 23, 42]
    awaitables = asyncio.gather(*[div7_tuple(x) for x in lost])
    print({k: v for k, v in awaitables})


if __name__ == '__main__':
    asyncio.run(main())

但是，这会导致异常：

> RuntimeError: await wasn't used with future 
> sys:1: RuntimeWarning:coroutine 'div7_tuple' was never awaited

如何用

asyncio.gather()

做到这一点？

奇怪的是，这对于构造未排序的对象来说不能以未排序的方式工作，因为如果我尝试以排序的方式它就可以工作：

async def div7(x):
    return x/7


async def main2():
    lost = [4, 8, 15, 16, 23, 42]
    print({k: await v for k, v in [(x, div7(x)) for x in lost]})

Answer 1

gather()

给你一个 Future 对象。如果您需要对象的结果（以便迭代它），您需要首先

await

：

async def main():
    lost = [4, 8, 15, 16, 23, 42]
    awaitables = asyncio.gather(*[div7_tuple(x) for x in lost])
    print({k: v for k, v in await awaitables})

或：

async def main():
    lost = [4, 8, 15, 16, 23, 42]
    awaitables = await asyncio.gather(*[div7_tuple(x) for x in lost])
    print({k: v for k, v in awaitables})