python3.6
使用了aiohttp, aiofiles库，异步操作
服务端代码如下，启动服务后，默认监听0.0.0.0:8080
没有做任何异常处理，适用于小文件，仅供参考

file_server.py:

import aiofilesimport asyncioimport osfrom aiohttp.web import Responsefrom aiohttp import webdef query_parse(req): obj = req.query_string queryitem = [] if obj: query = req.query.items() for item in query: queryitem.append(item) return dict(queryitem) else: return Noneasync def download(request): query = query_parse(request) filename = query.get('file') # 没有作任何异常处理，只有服务器上存在/tmp/files目录，并且请求的文件在该目录下，才能正常下载 file_dir = '/tmp/files' file_path = os.path.join(file_dir, filename) if os.path.exists(file_path): async with aiofiles.open(file_path, 'rb') as f: content = await f.read() if content: response = Response( content_type='application/octet-stream', headers={'Content-Disposition': 'attachment;filename={}'.format(filename)}, body=content ) return response else: return else: returnloop = asyncio.get_event_loop()app = web.Application(loop=loop)app.router.add_route(method='get', path='/download', handler=download)web.run_app(app)loop.close()

python3 file_server.py 运行服务端

客户端代码如下：
download.py:

import aiohttpimport asyncioimport aiofiles# 访问服务端download接口函数，下载服务器上指定目录（/tmp/files/）下的文件l5u.jpgurl = 'http://localhost:8080/download'params = {'file': 'l5u.jpg'}async def download(): async with aiohttp.ClientSession() as session: async with session.get(url, params=params) as resp: content = await resp.content.read() async with aiofiles.open('/tmp/test.jpg', 'wb') as f: await f.write(content)loop = asyncio.get_event_loop()loop.run_until_complete(download())

执行python3 download.py，查看/tmp/test.jpg是否存在，打开是否正常
或者直接使用浏览器访问http://localhost:8080/download?file=l5u.jpg， 下载下来的文件名称与请求发送的文件名称（服务器上存在的文件名称）一致