python3.0，标准库里的异步网络模块：select(非常底层) ，第三方异步网络库：Tornado，gevent

python3.4，asyncio：支持 TCP ，子进程

现在的asyncio，有了很多的模块已经在支持：aiohttp,aiodns,aioredis等等 https://github.com/aio-libs 这里列出了已经支持的内容，并在持续更新。

asyncio的使用上，感觉和gevent有异曲同工之妙

1、基础概念：

event_loop 事件循环：理解为一个循环的池，里面存放一些async关键词定义的协程函数，只有放到循环池里才能执行
coroutine 协程：协程对象，指一个使用async关键字定义的函数，它的调用不会立即执行函数，而是会返回一个协程对象。协程对象需要注册到事件循环，由事件循环调用。
task 任务：一个协程对象就是一个原生可以挂起的函数，任务则是对协程进一步封装，其中包含任务的各种状态。
future：代表将来执行或没有执行的任务的结果。它和task上没有本质的区别
async/await 关键字：python3.5 用于定义协程的关键字，async定义一个协程，await用于挂起阻塞的异步调用接口。

来看一个简单是示例

import time
import asyncionow = lambda : time.time()
async def do_some_work(x):    # 使用async关键字定义协程，当然协程不能直接运行，需要将协程加入到事件循环loop中print('Waiting: ', x)
start = now()
coroutine = do_some_work(2)     # 这里是一个协程对象，这个时候do_some_work函数并没有执行
loop = asyncio.get_event_loop()       # 第一步：创建一个事件循环（池）
loop.run_until_complete(coroutine)    # 第二步：将协程加入到事件循环loop，并启动事件循环2
Waiting:  2
TIME:  0.0004658699035644531

创建task

协程对象不能直接运行，需要包装成任务才能运行，上面是通过run_until_complete()方法包装成task（隐式包装），还有下面两种方式进行显式包装：

import asyncio
import timenow = lambda : time.time()
async def do_some_work(x):print('Waiting: ', x)
start = now()
coroutine = do_some_work(2)loop = asyncio.get_event_loop()
# task = asyncio.ensure_future(coroutine)  # 方式一
task = loop.create_task(coroutine)         # 方式二
print(task)loop.run_until_complete(task)
print(task)
print('TIME: ', now() - start)# 以下为输出
2
3
4
<Task pending coro=<do_some_work() running at /Users/ghost/Rsj217/python3.6/async/async-main.py:17>>
Waiting:  2
<Task finished coro=<do_some_work() done, defined at /Users/ghost/Rsj217/python3.6/async/async-main.py:17> result=None>
TIME:  0.0003490447998046875

创建task后，task在加入事件循环之前是pending状态，加入loop后运行中是running状态，loop调用完是Done，运行完是finished状态，虽说本质上协程函数和task指的东西都一样，但是task有了协程函数的状态。

其中loop.run_until_complete()接受一个future参数，futurn具体指代一个协程函数，而task是future的子类，所以我们不声明一个task直接传入协程函数也能执行。

关于上面通过loop.create_task(coroutine)创建task,同样的可以通过 asyncio.ensure_future(coroutine)创建task

关于这两个命令的官网解释： https://docs.python.org/3/library/asyncio-task.html#asyncio.ensure_future

绑定回调函数

通过task的task.add_done_callback(callback)方法绑定回调函数，回调函数接收一个future对象参数如task，在内部通过future.result()获得协程函数的返回值。

import asyncioasync def test(x):return x+3
def callback(y):print(y.result())
coroutine = test(5)
loop = asyncio.get_event_loop()
task = loop.create_task(coroutine)
task.add_done_callback(callback)
loop.run_until_complete(task)

通过add_done_callback方法给task任务添加回调函数，当task（也可以说是coroutine）执行完成的时候,就会调用回调函数。并通过参数future获取协程执行的结果。这里我们创建的task和回调里的future对象实际上是同一个对象

await（挂起耗时操作）

多任务声明了协程函数，也同时在loop中注册了，他的执行也是顺序执行的，因为在异步函数中没有声明那些操作是耗时操作，所以会顺序执行。await的作用就是告诉控制器这个步骤是耗时的，async可以定义协程对象，使用await可以针对耗时的操作进行挂起

import asyncio
import timeasync def test(1):time.sleep(1)print(time.time())
tasks = [asyncio.ensure_future(test()) for _ in range(3)]
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))1547187398.7611663
1547187399.7611988
1547187400.7632194Out[8]: 
({<Task finished coro=<test() done, defined at <ipython-input-5-1534f9ca2d8e>:4> result=None>,<Task finished coro=<test() done, defined at <ipython-input-5-1534f9ca2d8e>:4> result=None>,<Task finished coro=<test() done, defined at <ipython-input-5-1534f9ca2d8e>:4> result=None>},set())

上面执行并不是异步执行，而是顺序执行，但是改成下面形式那就是异步执行：

import asyncio
import time
async def test(t):await asyncio.sleep(1)   #  asyncio 的sleepprint(time.time())
tasks = [asyncio.ensure_future(test()) for _ in range(3)]
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))1547187398.7611663
1547187399.7611988
1547187400.7632194
Out[11]: 
({<Task finished coro=<test() done, defined at <ipython-input-9-3a874803716b>:4> result=None>,<Task finished coro=<test() done, defined at <ipython-input-9-3a874803716b>:4> result=None>,<Task finished coro=<test() done, defined at <ipython-input-9-3a874803716b>:4> result=None>},set())

可见三个任务的间隔时间几乎忽略不计，这里要注意可以使用await成功挂起的对应应该是下面三种：

原生异步函数（coroutine ）
由 types.coroutine() 修饰的生成器，这个生成器可以返回 coroutine 对象。
包含 __await 方法的对象返回的一个迭代器

所以即使使用saync修饰requests的方法也不支持异步，而是需要专门的异步网络请求库aiohttp，aiodns,aioredis。

aiohttp

aiohttp需要单独安装，然后和asyncio库一起使用，看一下案例

async def get(url):async with aiohttp.ClientSession() as session:async with session.get(url) as response:print(response)print(time.time())import time
async def request():url = "http://www.baidu.com"resulit = await get(url)tasks = [asyncio.ensure_future(request()) for _ in range(10)]
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0x94343a8f0000d2ac', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+fcb1f5fc4ea50a8475457d9dba4ffb75', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:19:54 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD4059F7858332E63E4CA:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD4059F7858332E63E4CA; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=26525_1426_21079_28132_28266; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.4161415
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0xb19b30e80000e08d', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+6035b8e98737e4cc11dcc73ec79566cc', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:19:48 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD405C594443631339D6D:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD405C594443631339D6D; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=26522_1423_21104_28132_28267_22158; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.417142
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0xfdf776e30000dfb4', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+0810232ebbebf660004801978cbc7056', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:20:15 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD40584DF85554050AB79:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD40584DF85554050AB79; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=1465_21118_28131_28267_20718; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.4221385
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0x879158430000a46a', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+acdef638e6acee7494d7fce1008c87ca', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:20:03 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD40593C8E085477DD125:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD40593C8E085477DD125; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=1448_21109_28131_28267; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.424138
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0xe5c481900000cd70', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+fb1596a42119b92bcb6a321cfd1bde58', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:19:51 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD405BD554041F5821AB7:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD405BD554041F5821AB7; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=1448_21105_18560_28132_28266_20719; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.4261389
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0x85ab35690000c4fd', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+15e5fc3bd83c4ffcdf9698e3264f7621', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:20:00 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD405C594443631339D6D:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD405C594443631339D6D; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=26522_1423_21104_28132_28267_22158; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.428144
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0x9620ed6b0000f26c', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+a2bfd2645e7c3d7514192a060f9644f5', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:20:12 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD4055EFEDF62083FAFD3:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD4055EFEDF62083FAFD3; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=1427_21127_28132_28267; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.4291408
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0x912a1be40000e841', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+599a770e18be144be77bd13c371daf0a', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:20:35 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD405106191D066098188:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD405106191D066098188; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=1424_21111_28132_28266; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.4311435
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0x943943940000b92b', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+17014bf10c56f72b235b529f8f9c177b', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:20:31 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD40504EF38ED596AEC59:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD40504EF38ED596AEC59; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=1446_21118_28131_26350_28267_22158; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.4331403
<ClientResponse(http://www.baidu.com) [200 OK]>
<CIMultiDictProxy('Bdpagetype': '1', 'Bdqid': '0xfd3e1b1f0000d880', 'Cache-Control': 'private', 'Connection': 'Keep-Alive', 'Content-Encoding': 'gzip', 'Content-Type': 'text/html', 'Cxy_all': 'baidu+39d965c50587bb578c5714a0d732b2e4', 'Date': 'Fri, 11 Jan 2019 07:20:37 GMT', 'Expires': 'Fri, 11 Jan 2019 07:20:25 GMT', 'P3p': 'CP=" OTI DSP COR IVA OUR IND COM "', 'Server': 'BWS/1.1', 'Set-Cookie': 'BAIDUID=76DA9E559DEFD4059A93CF4E300A8EEB:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'BIDUPSID=76DA9E559DEFD4059A93CF4E300A8EEB; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'PSTM=1547191237; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com', 'Set-Cookie': 'delPer=0; path=/; domain=.baidu.com', 'Set-Cookie': 'BDSVRTM=0; path=/', 'Set-Cookie': 'BD_HOME=0; path=/', 'Set-Cookie': 'H_PS_PSSID=1445_21113_28131_28267_22158; path=/; domain=.baidu.com', 'Vary': 'Accept-Encoding', 'X-Ua-Compatible': 'IE=Edge,chrome=1', 'Transfer-Encoding': 'chunked')>
1547191237.4341416

几个任务的时间之差基本忽略不计，那亲测发送一千个请求也就11秒完成，确实很给力。

多进程配合使用

asyncio、aiohttp需要配合aiomultiprocess库使用，版本要求至少3.6，贴上该库的github上的使用示例，目前还在验证：

Usage
Most of aiomultiprocess mimics the standard multiprocessing module whenever possible, while accounting for places that benefit from async functionality.

import asyncio
from aiohttp import request
from aiomultiprocess import Processasync def put(url, params):async with request("PUT", url, params=params) as response:passasync def main():p = Process(target=put, args=("https://jreese.sh", ))await pasyncio.run(main())# If you want to get results back from that coroutine, Worker makes that available:
import asyncio
from aiohttp import request
from aiomultiprocess import Workerasync def get(url):async with request("GET", url) as response:return await response.text("utf-8")async def main():p = Worker(target=get, args=("https://jreese.sh", ))response = await pasyncio.run(main())#If you want a managed pool of worker processes, then use Pool:
import asyncio
from aiohttp import request
from aiomultiprocess import Poolasync def get(url):async with request("GET", url) as response:return await response.text("utf-8")async def main():urls = ["https://jreese.sh", ...]async with Pool() as pool:result = await pool.map(get, urls)asyncio.run(main())

多协程并发

使用loop.run_until_complete(syncio.wait(tasks)) 也可以使用 loop.run_until_complete(asyncio.gather(*tasks)） ,前者传入task列表，会对task进行解包操作。

协程嵌套

顾名思义是一个协程中调用另一个协程，但是涉及到两个协程函数的结果处理和返回。

async def get(url):async with aiohttp.ClientSession() as session:async with session.get(url) as response:print(response)print(time.time())import time
async def request():url = "http://www.baidu.com"resulit = await get(url)tasks = [asyncio.ensure_future(request()) for _ in range(10000)]
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))

被调用协程返回结果有下列三种方式;

async def get(url):async with aiohttp.ClientSession() as session:async with session.get(url) as response:print(response)print(time.time())
async def request():url = "http://www.baidu.com"tasks = [asyncio.ensure_future(url) for _ in range（1000）]
方式一：dones, pendings = await asyncio.wait(tasks) # 返回future对象，不返回直接结果for task in dones:print('Task ret: ', task.result())
方式二：results = await asyncio.gather(*tasks) # 直接返回结果方式三：for task in asyncio.as_completed(tasks):result = await taskprint('Task ret: {}'.format(result)) # 迭代方式返回结果tasks = asyncio.ensure_future(request())
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))

停止协程任务

实现结束task有两种方式：关闭单个task、关闭loop，涉及主要函数：

asyncio.Task.all_tasks()获取事件循环任务列表
KeyboardInterrupt捕获停止异常（Ctrl+C）
loop.stop()停止任务循环
task.cancel()取消单个任务
loop.run_forever()
loop.close()关闭事件循环，不然会重启

重启

方式一：适用于内嵌协程函数，先取内嵌协程任务

async def get(url):
async with aiohttp.ClientSession() as session:
async with session.get(url) as response:
print(response)
print(time.time())
async def request():
url = "http://www.baidu.com"
tasks = [asyncio.ensure_future(url) for _ in range（1000）]
dones, pendings = await asyncio.wait(tasks)task = asyncio.ensure_future(request())
loop = asyncio.get_event_loop()
try:
loop.run_until_complete(task)
except KeyboardInterrupt as e:
asyncio.gather(*asyncio.Task.all_tasks()).cancel()
loop.stop()
loop.run_forever()
finally:
loop.close()

方式二：适用于无内嵌函数，直接遍历协程任务

loop = asyncio.get_event_loop()
try:
loop.run_until_complete(asyncio.wait(tasks))
except KeyboardInterrupt as e:
for task in asyncio.Task.all_tasks():
print(task.cancel())
loop.stop()
loop.run_forever()
finally:
loop.close()