python aiohttp里面用try except导致不异步?

Question

async def get_res(url,i):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as r:
            # json_body = await r.json()
            try:
                resp_data = await r.text()
            except UnicodeDecodeError:
                print('error')
                pass
                # resp_data = await r.read()
    print(f'{i} req done')
    return r.headers

async def main2():
    workers = [
        asyncio.create_task(get_res('http://img.alicdn.com/imgextra/i4/35034182/O1CN01dxL9pi1glOv3l5YW1_!!35034182.jpg?p={}'.format(i), i))
        for i in range(10)
    ]
    all_body=await asyncio.gather(*workers)

if __name__ == '__main__':
    #asyncio.run(main())
    loop = asyncio.get_event_loop()
    loop.run_until_complete(main2())

resp_data = await r.text()
这个代码会触发try except,这个时候10个请求是一个一个输出结果的.
改成resp_data = await r.read()
就会一起输出
是为什么呢