def func():    pass
async def coro_func():    pass
print(func.__class__)  # <class 'function'>print(coro_func.__class__)  # <class 'function'>
# 兩者都是 <class 'function'> 類型print(func.__code__.co_flags & 0x80)  # 0print(coro_func.__code__.co_flags & 0x80)  # 128
# 但如果是協(xié)程函數(shù)，那么 co_flags & 0x80 為真

def gen_func():    yield    return "gen result"
async def coro_func():    return f"coroutine result"

# 先來(lái)看看生成器gen = gen_func()gen.__next__()try:    gen.__next__()except StopIteration as e:    print(e.value)  # gen result# 當(dāng)生成器 return 時(shí),，會(huì)拋出一個(gè) StopIteration# 并將返回值設(shè)置在里面,，因此 return 只是一個(gè)語(yǔ)法糖# 對(duì)于協(xié)程亦是如此coro = coro_func()try:    coro.__await__().__next__()except StopIteration as e:    print(e.value)  # coroutine result

async def coro_func():    return f"coroutine result"
async def main():    result = await coro_func()    return f"來(lái)自 coro_func 的返回值: {result}"
try:    main().__await__().__next__()except StopIteration as e:    print(e)# 來(lái)自 coro_func 的返回值: coroutine result

def gen_func():    yield 123    return "result"
def middle():    res = yield (yield from gen_func())    print(res)
# 我們說(shuō)委托生成器有一個(gè)重要的作用# 它會(huì)在子生成器和調(diào)用方之間建立一個(gè)雙向通道g = middle()# 此時(shí)是調(diào)用方和子生成器之間直接通信print(g.__next__())  # 123# 顯然此時(shí)要拋異常了，那么委托生成器要負(fù)責(zé)兜底# 會(huì)拿到子生成器的返回值,，在自身內(nèi)部尋找下一個(gè) yieldprint(g.__next__())  # result

async def coro_func():    return f"coroutine result"
async def main():    result = await coro_func()    return f"來(lái)自 coro_func 的返回值: {result}"
# main() 里面 await 一個(gè)子協(xié)程# 此時(shí) await 同樣會(huì)建立一個(gè)雙向通道# 子協(xié)程會(huì)和調(diào)用方直接通信# 另外這里的調(diào)用方可以是我們手動(dòng)調(diào)用,，也可以是事件循環(huán)try:    # 子協(xié)程要拋異常了,，那么 main() 要兜底    # await 會(huì)捕獲異常，然后將返回值取出來(lái)    main().__await__().__next__()except StopIteration as e:    print(e.value)# 來(lái)自 coro_func 的返回值: coroutine result

async def coro_func():    return f"coroutine result"
async def main():    try:        coro_func().__await__().__next__()    except StopIteration as e:        return f"來(lái)自 coro_func 的返回值: {e.value}"
try:    main().__await__().__next__()except StopIteration as e:    print(e.value)# 來(lái)自 coro_func 的返回值: coroutine result

s = """async def coro_func():    return f"coroutine result"
async def main():    result = await coro_func()    return f"來(lái)自 coro_func 的返回值: {result}""""if __name__ == '__main__':    import dis    dis.dis(compile(s, "<file>", "exec"))

case TARGET(GET_AWAITABLE): {    PREDICTED(GET_AWAITABLE);    //上一步的 CALL_FUNCTION 指令會(huì)構(gòu)建一個(gè)協(xié)程    //并且將協(xié)程壓入到棧頂,，也就是這里的iterable    PyObject *iterable = TOP();    //調(diào)用協(xié)程的 __await__    PyObject *iter = _PyCoro_GetAwaitableIter(iterable);
    //...    //將 iter 設(shè)置為新的棧頂元素    SET_TOP(iter); /* Even if it's NULL */
    if (iter == NULL) {        goto error;    }
    PREDICT(LOAD_CONST);    DISPATCH();}

PyObject *_PyCoro_GetAwaitableIter(PyObject *o){    unaryfunc getter = NULL;    PyTypeObject *ot;    //如果是一個(gè)使用 async def 定義的協(xié)程    //或者是一個(gè)被 @asyncio.coroutine 裝飾的協(xié)程(不推薦)    //那么直接返回    if (PyCoro_CheckExact(o) || gen_is_coroutine(o)) {        /* 'o' is a coroutine. */        Py_INCREF(o);        return o;    }
    //如果不是一個(gè)協(xié)程,，那么它必須實(shí)現(xiàn) __await__    //對(duì)應(yīng) tp_as_async 的 am_await 成員    ot = Py_TYPE(o);    if (ot->tp_as_async != NULL) {        getter = ot->tp_as_async->am_await;    }    //如果實(shí)現(xiàn)了 __await__    if (getter != NULL) {        //那么進(jìn)行調(diào)用        PyObject *res = (*getter)(o);        if (res != NULL) {            //如果一個(gè)對(duì)象不是協(xié)程，但又實(shí)現(xiàn)了 __await__            //那么 __await__ 必須返回迭代器            if (PyCoro_CheckExact(res) || gen_is_coroutine(res)) {                /* __await__ must return an *iterator*, not                   a coroutine or another awaitable (see PEP 492) */                PyErr_SetString(PyExc_TypeError,                                "__await__() returned a coroutine");                Py_CLEAR(res);            } else if (!PyIter_Check(res)) {                PyErr_Format(PyExc_TypeError,                             "__await__() returned non-iterator "                             "of type '%.100s'",                             Py_TYPE(res)->tp_name);                Py_CLEAR(res);            }        }        return res;    }    //否則就說(shuō)明,，該對(duì)象不可以被 await    PyErr_Format(PyExc_TypeError,                 "object %.100s can't be used in 'await' expression",                 ot->tp_name);    return NULL;}

class A:
    def __await__(self):        return coro_func().__await__()
async def coro_func():    return f"coroutine result"
async def main():    # A() 不是一個(gè)協(xié)程，那么它必須實(shí)現(xiàn) __await__    # 并且 __await__ 里面必須返回一個(gè)迭代器    # 只有這樣,，才能調(diào)用 __next__ 方法    result = await A()    return f"來(lái)自 A().__await__ 的返回值: {result}"

try:    main().__await__().__next__()except StopIteration as e:    print(e.value)# 來(lái)自 A().__await__ 的返回值: coroutine result

import asyncio
async def coro_func(n):    await asyncio.sleep(n)    print(f"我睡了 {n} 秒")    return f"coroutine result"
async def main():    # 基于協(xié)程創(chuàng)建 asyncio.Task 對(duì)象    task1 = asyncio.create_task(coro_func(3))    task2 = asyncio.create_task(coro_func(1))        await task1

loop = asyncio.get_event_loop()loop.run_until_complete(main())"""我睡了 1 秒我睡了 3 秒"""

import asyncio
async def coro_func(n):    await asyncio.sleep(n)    print(f"我睡了 {n} 秒")    return f"coroutine result"
async def main():    task1 = asyncio.create_task(coro_func(3))    task2 = asyncio.create_task(coro_func(1))    task3 = coro_func(1)
    await task1

loop = asyncio.get_event_loop()loop.run_until_complete(main())"""我睡了 1 秒我睡了 3 秒"""

import asyncioimport time
async def coro_func(n):    await asyncio.sleep(n)    print(f"我睡了 {n} 秒")
async def main1():    task1 = asyncio.create_task(coro_func(3))    task2 = asyncio.create_task(coro_func(3))
    await task1    await task2
async def main2():    await coro_func(3)    await coro_func(3)

loop = asyncio.get_event_loop()start = time.perf_counter()loop.run_until_complete(main1())print(time.perf_counter() - start)"""我睡了 3 秒我睡了 3 秒3.0026131"""
start = time.perf_counter()loop.run_until_complete(main2())print(time.perf_counter() - start)"""我睡了 3 秒我睡了 3 秒6.0027813000000005"""