from greenlet import greenlet
def func1():
 print(1)  # 第1步：輸出 1
 gr2.switch() # 第3步：切換到 func2 函數(shù)
 print(2)  # 第6步：輸出 2
 gr2.switch() # 第7步：切換到 func2 函數(shù)，從上一次執(zhí)行的位置繼續(xù)向后執(zhí)行
def func2():
 print(3)  # 第4步：輸出 3
 gr1.switch() # 第5步：切換到 func1 函數(shù)，從上一次執(zhí)行的位置繼續(xù)向后執(zhí)行
 print(4)  # 第8步：輸出 4
gr1 = greenlet(func1)
gr2 = greenlet(func2)
gr1.switch() # 第1步：去執(zhí)行 func1 函數(shù)

def func1():
 yield 1#第一步執(zhí)行這里會生成1
 yield from func2() #這里會跳到func2，然后執(zhí)行里面的代碼，執(zhí)行完func2函數(shù)后會繼續(xù)以跳轉之前的狀態(tài)繼續(xù)執(zhí)行以下代碼
 yield 2
def func2():
 yield 3
 yield 4 
# 這里是一個生成器對象
f1 = func1()
# 遍歷執(zhí)行生成器
for item in f1:
 print(item)

import asyncio
#這就是一個用協(xié)程實現(xiàn)的函數(shù)
@asyncio.coroutine
def func1():
 print(1)
 yield from asyncio.sleep(2)  # 遇到IO耗時操作，自動化切換到tasks中的其他任務
 print(2)
loop = asyncio.get_event_loop()
#執(zhí)行
loop.run_until_complete(func1())

import asyncio
@asyncio.coroutine
def func1():
 print(1)
 yield from asyncio.sleep(2)  # 遇到IO耗時操作，自動化切換到tasks中的其他任務
 print(2)
@asyncio.coroutine
def func2():
 print(3)
 yield from asyncio.sleep(2) # 遇到IO耗時操作，自動化切換到tasks中的其他任務
 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)
 print(2)
async def func2():
 print(3)
 await asyncio.sleep(2)
 print(4)
tasks = [
 asyncio.ensure_future(func1()),
 asyncio.ensure_future(func2())
]
loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))

import requests
def download_image(url):
 print("開始下載:",url)
 # 發(fā)送網(wǎng)絡請求，下載圖片
 response = requests.get(url)
 print("下載完成")
 # 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)
if __name__ == '__main__':
 url_list = [
  'https://www3.autoimg.cn/newsdfs/g26/M02/35/A9/120x90_0_autohomecar__ChsEe12AXQ6AOOH_AAFocMs8nzU621.jpg',
  'https://www2.autoimg.cn/newsdfs/g30/M01/3C/E2/120x90_0_autohomecar__ChcCSV2BBICAUntfAADjJFd6800429.jpg',
  'https://www3.autoimg.cn/newsdfs/g26/M0B/3C/65/120x90_0_autohomecar__ChcCP12BFCmAIO83AAGq7vK0sGY193.jpg'
 ]
 for item in url_list:
  download_image(item)

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://www3.autoimg.cn/newsdfs/g26/M02/35/A9/120x90_0_autohomecar__ChsEe12AXQ6AOOH_AAFocMs8nzU621.jpg',
'https://www2.autoimg.cn/newsdfs/g30/M01/3C/E2/120x90_0_autohomecar__ChcCSV2BBICAUntfAADjJFd6800429.jpg',
'https://www3.autoimg.cn/newsdfs/g26/M0B/3C/65/120x90_0_autohomecar__ChcCP12BFCmAIO83AAGq7vK0sGY193.jpg'
  ]
  tasks = [asyncio.create_task(fetch(session, url)) for url in url_list]
  await asyncio.wait(tasks)
if __name__ == '__main__':
 asyncio.run(main())