最近一直在閱讀有關 python 并發的內容 realpython - python concurrency我的主要關注asyncio點是相當新的。執行異步活動的代碼塊使用asyncio并aiohttp在直接運行時運行良好。但是，當我將代碼添加到我的燒瓶藍圖時，它會引發此錯誤：RuntimeError: There is no current event loop in thread 'Thread-2'出于演示目的，我制作了一個演示燒瓶應用程序。萬一有人想測試一下。main.pyfrom flask import Flaskfrom my_blueprint import my_blueprint#Define flask appapp = Flask(__name__)#load blueprintsapp.register_blueprint(my_blueprint,url_prefix='/demo')#start flaskif __name__ == '__main__':    app.run(debug=True)my_blueprint.pyfrom flask import Blueprint,request, jsonify,abort,make_responsefrom flask import make_responseimport asyncioimport timeimport aiohttpmy_blueprint = Blueprint('my_blueprint', __name__)@my_blueprint.route('/',methods=['GET'])def home():    #code block    async def download_site(session, url):        async with session.get(url) as response:            print("Read {0} from {1}".format(response.content_length, url))    async def download_all_sites(sites):        async with aiohttp.ClientSession() as session:            tasks = []            for url in sites:                task = asyncio.ensure_future(download_site(session, url))                tasks.append(task)            await asyncio.gather(*tasks, return_exceptions=True)    sites = ["https://www.jython.org","http://olympus.realpython.org/dice"]*20    start_time = time.time()    asyncio.get_event_loop().run_until_complete(download_all_sites(sites))    duration = time.time() - start_time    return jsonify({"status":f"Downloaded {len(sites)} sites in {duration} seconds"})    #end of code block