如何调试异步python代码？

Question

I was playing around async code lately, when I tried to debug the code in PyCharm I saw some really strange behaviour I think it's because of the underlying architectureimport asyncio. This is the code I'm talking about.

async def compute(x, y):
    print("Compute %s + %s ..." % (x, y))
    await asyncio.sleep(1.0)
    return x + y

tasks = [compute(x,x) for x in range(10)]
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))
loop.close()

It's strange because when I set breakpoint inside the coroutine execution is never breaked and whole code completes running easily besides this I don't get much details of event loop(except some mess in the stack).

So here are my questions

1. Is there any standards or some good practice on debugging async code?
2. How to peek into execution flow of event loop?
3. Why isn't it breaking inside the async function?

Answer 1

Just to add here as sample here:

async def compute(x, y):
    print("Compute %s + %s ..." % (x, y))
    await asyncio.sleep(1.0) # add breakpoint here and then run it in debug mode
    return x + y

tasks = [compute(x,x) for x in range(10)]
loop = asyncio.get_event_loop()
loop.set_debug(True)
loop.run_until_complete(asyncio.wait(tasks))
loop.close()