如何使用python aiohttp库下载多个网页？

import asyncio
import aiohttp

async def download_page(url):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as response:
            return await response.text()

async def download_pages(urls):
    tasks = []
    async with aiohttp.ClientSession() as session:
        for url in urls:
            task = asyncio.ensure_future(download_page(url))
            tasks.append(task)
        return await asyncio.gather(*tasks)

urls = ['http://example.com/page1', 'http://example.com/page2', 'http://example.com/page3']
loop = asyncio.get_event_loop()
pages = loop.run_until_complete(download_pages(urls))

pip install aiohttp