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- """
- aiohttp - 异步HTTP网络访问
- 异步I/O（异步编程）- 只使用一个线程（单线程）来处理用户请求
- 用户请求一旦被接纳，剩下的都是I/O操作，通过多路I/O复用也可以达到并发的效果
- 这种做法与多线程相比可以让CPU利用率更高，因为没有线程切换的开销
- Redis/Node.js - 单线程 + 异步I/O
- Celery - 将要执行的耗时间的任务异步化处理
- 异步I/O事件循环 - uvloop
- """
- import asyncio
- import re
- import aiohttp
- async def fetch(session, url):
- async with session.get(url, ssl=False) as resp:
- return await resp.text()
- async def main():
- pattern = re.compile(r'\<title\>(?P<title>.*)\<\/title\>')
- urls = ('https://www.python.org/',
- 'https://git-scm.com/',
- 'https://www.jd.com/',
- 'https://www.taobao.com/',
- 'https://www.douban.com/')
- async with aiohttp.ClientSession() as session:
- for url in urls:
- html = await fetch(session, url)
- print(pattern.search(html).group('title'))
- if __name__ == '__main__':
- loop = asyncio.get_event_loop()
- loop.run_until_complete(main())
- loop.close()
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