请问下面异步嵌套的 await 为什么会导致 Task <Task pending coro=<fetch() running at xxxx.py:45> cb=[gather.<locals>._done_callback() 回调失败 ？

加入了异步插入 mongo 后导致的，去掉入库那一段就没问题。

 mongo_client = AsyncIOMotorClient(connect_uri) collection = mongo_client['db_stock']['new_stock_ttjj']  def parse_json(content):    # 解析     content += ';function getV(){return hsEnHLwG;}'     ctx = execjs.compile(content)     result = ctx.call('getV')     return result  async def update_data(data):    # 异步 mongo 入库      code = data['securitycode']     found =  await collection.find_one({'securitycode':code})     if not found:         await collection.insert_one(data)   async def fetch(session,page):      async with session.get(home_url.format(page),headers=headers) as resp:         content = await resp.text()          try:             js_content = parse_json(content)             for stock_info in js_content['data']:                 securityshortname = stock_info['securityshortname']                  print(securityshortname)                 await update_data(stock_info)         except Exception as e:             print(e)   async def main():     async with aiohttp.ClientSession() as session:         async with session.get(home_url.format(1), headers=headers) as resp:              content = await resp.text()             js_data = parse_json(content)             pages = js_data['pages']             tasks =[]             for page in range(1,pages+1):                 task = asyncio.ensure_future(fetch(session,page))                 tasks.append(task)              await asyncio.gather(*tasks)  asyncio.run(main())