asyncio 的结果不如预期

Question

我正在学习asyncio 库来完成一些我想要完成的任务。我编写了以下代码来教自己如何在执行原始任务时切换到另一个任务。正如您在下面看到的，应该执行summation()，直到满足它应该跳转到secondaryTask() 的条件。在secondaryTask() 完成后，它应该返回到summation()，希望它在那里完成。潜在结果应该是sum=1225 和mul=24。

import asyncio, time


async def summation():
    print('Running summation from 0 to 50:')
    sum = 0
    for i in range(25):
        sum = sum + i
        if i != 25:
            time.sleep(0.1)
        else:
            await asyncio.sleep(0) # pretend to be non-blocking work (Jump to the next task)
    print('This message is shown because summation() is completed! sum= %d' % sum)


async def secondaryTask():
    print('Do some secondaryTask here while summation() is on progress')
    mul = 1
    for i in range(1, 5):
        mul = mul * i
        time.sleep(0.1)
    await asyncio.sleep(0)
    print('This message is shown because secondaryTask() is completed! Mul= %d' % mul)

t0 = time.time()
ioloop = asyncio.get_event_loop()
tasks = [ioloop.create_task(summation()), ioloop.create_task(secondaryTask())]
wait_tasks = asyncio.wait(tasks)
ioloop.run_until_complete(wait_tasks)
ioloop.close()
t1 = time.time()
print('Total time= %.3f' % (t1-t0))

此代码未按预期执行，因为 sum=300 与 sum=1225 相反。显然，summation() 在处理 secondaryTask() 时不会继续。如何修改summation() 才能在后台对剩余的 25 个值求和？

谢谢

Answer 1

这只是你的粗心。你想运行summation从0到50，你的summation函数应该是for i in range(50)