1、asyncio aiohttp aiofile 异步爬取图片

时间：2019-03-04 22:26:32 阅读：378 评论：0 收藏：0 [点我收藏+]

前后折腾了好多天，不废话，先直接上代码，再分析：

 1 import aiohttp
 2 import asyncio
 3 import aiofiles
 4 
 5 header = {‘User-Agent‘: ‘Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/22.0.1207.1 Safari/537.1‘,
 6                   ‘Referer‘: ‘https://www.mzitu.com/‘,
 7                    ‘Accept‘: "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
 8                    ‘Accept-Encoding‘: ‘gzip‘,
 9                    }
10 
11 async def fetch(session, url):
12     async with session.get(url, proxy=‘http://59.62.164.252:9999‘) as response:
13         return await response.read()
14 
15 async def main():
16     async with aiohttp.ClientSession(headers=header) as session:
17         content = await fetch(session, ‘https://i.meizitu.net/thumbs/2019/03/174061_01e35_236.jpg‘)
18         print(content)
19         async with aiofiles.open(‘D:/a.jpg‘, ‘wb‘) as f:
20             f.write(content)
21 
22 loop = asyncio.get_event_loop()
23 loop.run_until_complete(main())
24 loop.close()

开始心路历程：

1、看了廖雪峰老师python教程中协程一章节、《流畅的python》中协程一章节，以及前前后后网上查询的资料，不管怎么改均报错，人接近暴走状态。

最后Google查询ClientSession：Client Reference，复制源码做尝试：

 1 import aiohttp
 2 import asyncio
 3 
 4 async def fetch(client):
 5     async with client.get(‘http://python.org‘) as resp:
 6         assert resp.status == 200
 7         return await resp.text()
 8 
 9 async def main():
10     async with aiohttp.ClientSession() as client:
11         html = await fetch(client)
12         print(html)
13 
14 loop = asyncio.get_event_loop()
15 loop.run_until_complete(main())

运行成功

2、改为下载图片，并想fetch函数能不能直接返回response？

 1 import aiohttp
 2 import asyncio
 3 import aiofiles
 4 
 5 header = {‘User-Agent‘: ‘Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/22.0.1207.1 Safari/537.1‘,
 6                   ‘Referer‘: ‘https://www.mzitu.com/‘,
 7                    ‘Accept‘: "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
 8                    ‘Accept-Encoding‘: ‘gzip‘,
 9                    }
10 
11 async def fetch(session, url):
12     async with session.get(url) as response:
13         return response
14 
15 async def main():
16     async with aiohttp.ClientSession() as session:
17         response = await fetch(session, ‘https://i.meizitu.net/thumbs/2019/03/174061_01e35_236.jpg‘)
18         print(response.read())
19         with open(‘D:/a.jpg‘, ‘wb‘) as f:
20             f.write(response.read())
21 
22 loop = asyncio.get_event_loop()
23 loop.run_until_complete(main())
24 loop.close()