LearnPython/python_coroutine.py

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# _*_ coding: utf-8 _*_
"""
python_coroutine.py by xianhu
"""
import asyncio
import aiohttp
import threading
# 生产者、消费者例子
def consumer(): # 定义消费者由于有yeild关键词此消费者为一个生成器
print("[Consumer] Init Consumer ......")
r = "init ok" # 初始化返回结果,并在启动消费者时,返回给生产者
while True:
n = yield r # 消费者通过yield关键词接收生产者产生的消息同时返回结果给生产者
print("[Consumer] conusme n = %s, r = %s" % (n, r))
r = "consume %s OK" % n # 消费者消费结果,下个循环返回给生产者
def produce(c): # 定义生产者,此时的 c 为一个生成器
print("[Producer] Init Producer ......")
r = c.send(None) # 启动消费者生成器,同时第一次接收返回结果
print("[Producer] Start Consumer, return %s" % r)
n = 0
while n < 5:
n += 1
print("[Producer] While, Producing %s ......" % n)
r = c.send(n) # 向消费者发送消息,同时准备接收结果。此时会切换到消费者执行
print("[Producer] Consumer return: %s" % r)
c.close() # 关闭消费者生成器
print("[Producer] Close Producer ......")
# produce(consumer())
# 异步IO例子适配Python3.4使用asyncio库
@asyncio.coroutine
def hello(index): # 通过装饰器asyncio.coroutine定义协程
print('Hello world! index=%s, thread=%s' % (index, threading.currentThread()))
yield from asyncio.sleep(1) # 模拟IO任务
print('Hello again! index=%s, thread=%s' % (index, threading.currentThread()))@asyncio.coroutine
loop = asyncio.get_event_loop() # 得到一个事件循环模型
tasks = [hello(1), hello(2)] # 初始化任务列表
loop.run_until_complete(asyncio.wait(tasks)) # 执行任务
loop.close() # 关闭事件循环列表
# 异步IO例子适配Python3.5使用async和await关键字
async def hello1(index): # 通过关键字async定义协程
print('Hello world! index=%s, thread=%s' % (index, threading.currentThread()))
await asyncio.sleep(1) # 模拟IO任务
print('Hello again! index=%s, thread=%s' % (index, threading.currentThread()))
loop = asyncio.get_event_loop() # 得到一个事件循环模型
tasks = [hello1(1), hello1(2)] # 初始化任务列表
loop.run_until_complete(asyncio.wait(tasks)) # 执行任务
loop.close() # 关闭事件循环列表
# aiohttp 实例
async def get(url):
async with aiohttp.ClientSession() as session:
async with session.get(url) as resp:
print(url, resp.status)
print(url, await resp.text())
loop = asyncio.get_event_loop() # 得到一个事件循环模型
tasks = [ # 初始化任务列表
get("http://zhushou.360.cn/detail/index/soft_id/3283370"),
get("http://zhushou.360.cn/detail/index/soft_id/3264775"),
get("http://zhushou.360.cn/detail/index/soft_id/705490")
]
loop.run_until_complete(asyncio.wait(tasks)) # 执行任务
loop.close() # 关闭事件循环列表