def func1():
    print(1)
    ...   # 協(xié)程介入
    print(2)
    
def func2():
    print(3)
    ...   # 協(xié)程介入
    print(4)

func1()
func2()

import asyncio

@asyncio.coroutine
def func1():
    print(1)
    yield from asyncio.sleep(2)  # 遇到IO耗時(shí)操作，自動化切換到tasks中的其他任務(wù)
    print(2)

@asyncio.coroutine
def func2():
    print(3)
    yield from asyncio.sleep(2) # 遇到IO耗時(shí)操作，自動化切換到tasks中的其他任務(wù)
    print(4)

tasks = [
    asyncio.ensure_future( func1() ),
    asyncio.ensure_future( func2() )
]

loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))

import asyncio

async def func1():
    print(1)
    await asyncio.sleep(2)  # 耗時(shí)操作  
    print(2)

async def func2():
    print(3)
    await asyncio.sleep(2)   # 耗時(shí)操作
    print(4)

tasks = [
    asyncio.ensure_future(func1()),
    asyncio.ensure_future(func2())
]

loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))

# requests庫僅支持同步的http網(wǎng)絡(luò)請求
import requests

def download_image(url):
  print("開始下載:",url)
  # 發(fā)送網(wǎng)絡(luò)請求，下載圖片
  response = requests.get(url)
  # 圖片保存到本地文件
  file_name = url.rsplit('_')[-1]
  with open(file_name, mode='wb') as file_object:
      file_object.write(response.content)
print("下載完成")


if __name__ == '__main__':
  url_list = [
      'https://www.1.jpg',
      'https://www.2.jpg',
      'https://www.3.jpg'
  ]
  for item in url_list:
      download_image(item)

# aiohttp 為支持異步編程的http請求庫
import aiohttp
import asyncio

async def fetch(session, url):
  print("發(fā)送請求：", url)
  async with session.get(url, verify_ssl=False) as response:
      content = await response.content.read()
      file_name = url.rsplit('_')[-1]
      with open(file_name, mode='wb') as file_object:
          file_object.write(content)

async def main():
  async with aiohttp.ClientSession() as session:
      url_list = [
          'https://www.1.jpg',
          'https://www.2.jpg',
          'https://www.3.jpg'
      ]
      tasks = [asyncio.create_task(fetch(session, url)) for url in url_list]
      await asyncio.wait(tasks)


if __name__ == '__main__':
  asyncio.run(main())

　# 偽代碼
任務(wù)列表 = [ 任務(wù)1, 任務(wù)2, 任務(wù)3,... ]
while True:
    可執(zhí)行的任務(wù)列表，已完成的任務(wù)列表 = 去任務(wù)列表中檢查所有的任務(wù)，將'可執(zhí)行'和'已完成'的任務(wù)返回
    for 就緒任務(wù) in 已準(zhǔn)備就緒的任務(wù)列表:
        執(zhí)行已就緒的任務(wù)
         
    for 已完成的任務(wù) in 已完成的任務(wù)列表:
        在任務(wù)列表中移除 已完成的任
         
    如果 任務(wù)列表 中的任務(wù)都已完成，則終止循環(huán)　

# 方式一：
import asyncio
# 生成或獲取一個(gè)事件循環(huán)
loop = asyncio.get_event_loop()
# 將任務(wù)添加到事件循環(huán)中
loop.run_until_complete(任務(wù))

# 方式二（python3.7及以上版本支持）：
asyncio.run( 任務(wù) )

# 協(xié)程函數(shù)
async def func():
    pass
# 協(xié)程對象
result = func()

import asyncio 
async def func():
    print("執(zhí)行協(xié)程函數(shù)內(nèi)部代碼！")
result = func()

# 調(diào)用方法1：
# loop = asyncio.get_event_loop()
# loop.run_until_complete( result )

# 調(diào)用方法2：
asyncio.run( result )

import asyncio

async def others():
    print("start")
    await asyncio.sleep(2)
    print('end')
    return '返回值'

async def func():
    print("執(zhí)行協(xié)程函數(shù)內(nèi)部代碼")
    # await等待對象的值得到結(jié)果之后再繼續(xù)向下走
    response = await others()
    print("IO請求結(jié)束，結(jié)果為：", response)

asyncio.run( func() )

async def module_a():
    print("start module_a")
    await asyncio.sleep(2) # 模擬 module_a 的io操作
    print('end module_a')
    return 'module_a 完成'

async def module_b():
    print("start module_b")
    await asyncio.sleep(1) # 模擬 module_a 的io操作
    print('end module_b')
    return 'module_b 完成'  

task_list = [
    module_a(),
    module_b(), 
]

done,pending = asyncio.run( asyncio.wait(task_list) )
print(done)

import asyncio
import aiomysql
import os
import aiofiles as aiofiles
from aiohttp import ClientSession

async def get_app():

    url = "http://www.123.apk"
    async with ClientSession() as session:
        # 網(wǎng)絡(luò)IO請求，獲取響應(yīng)
        async with session.get(url)as res:
            if res.status == 200:
                print("下載成功", res)
                # 磁盤IO請求，讀取響應(yīng)數(shù)據(jù)
                apk = await res.content.read()
                async  with  aiofiles.open("demo2.apk", "wb") as f:
                    # 磁盤IO請求，數(shù)據(jù)寫入本地磁盤
                    await f.write(apk)
            else:
                print("下載失敗")

async def excute_sql(sql):
    # 網(wǎng)絡(luò)IO操作：連接MySQL
    conn = await aiomysql.connect(host='127.0.0.1', port=3306, user='root', password='123', db='mysql', )
    # 網(wǎng)絡(luò)IO操作：創(chuàng)建CURSOR
    cur = await conn.cursor()
    # 網(wǎng)絡(luò)IO操作：執(zhí)行SQL
    await cur.execute(sql)
    # 網(wǎng)絡(luò)IO操作：獲取SQL結(jié)果
    result = await cur.fetchall()
    print(result)
    # 網(wǎng)絡(luò)IO操作：關(guān)閉鏈接
    await cur.close()
    conn.close()

task_list = [get_app(), execute_sql(sql="SELECT Host,User FROM user")]
asyncio.run(asyncio.wait(task_list))

import requests
def send_request(url):
    response = requests.get(url)
    return response.text
# 向服務(wù)器1發(fā)送請求
response1 = send_request("http://server1.com")

# 向服務(wù)器2發(fā)送請求
response2 = send_request("http://server2.com")

# 向服務(wù)器3發(fā)送請求
response3 = send_request("http://server3.com")

import asyncio
import aiohttp
async def send_request(url):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as response:
            return await response.text()
# 向服務(wù)器1發(fā)送請求
response1 = asyncio.run(send_request("http://server1.com"))

# 向服務(wù)器2發(fā)送請求
response2 = asyncio.run(send_request("http://server2.com"))

# 向服務(wù)器3發(fā)送請求
response3 = asyncio.run(send_request("http://server3.com"))