请问下面异步嵌套的 await 为什么会导致 mongo 入库失败

 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())

await

Async

content

resp

4 条回复 2020-11-25 17:25:26 +08:00

keepeye

2020 年 11 月 25 日

task = asyncio.ensure_future(fetch(session,page))
似乎可以改成
task = fetch(session,page)

yagamil

2020 年 11 月 25 日

@keepeye 问题不在这里。

yagamil

2020 年 11 月 25 日

找到原因：
def run(main, *, debug=False):
if events._get_running_loop() is not None:
raise RuntimeError(
"asyncio.run() cannot be called from a running event loop")

if not coroutines.iscoroutine(main):
raise ValueError("a coroutine was expected, got {!r}".format(main))

loop = events.new_event_loop()

asyncio.run 内部定义了一个 loop，
moto 初始化的时候内部也用了这个。

用 loop 定义，motor 的定义放在 loop 后面。

n37r09u3

2020 年 11 月 25 日

放后面是用同一个 loop 了吧？