Asyncio + python-telegram-bot 无限线程循环问题

Question

我正在使用 python-telegram-bot 库创建一个 Telegram 机器人，它能够应答消息，同时每 X 秒运行一次后台任务，如果满足条件，则发送 Telegram 消息。

我面临一个问题，每次满足条件并且代码发送消息时，都会创建一个新线程。我尝试隔离所有内容并提供了以下示例代码：

import asyncio
import logging
import threading
from telegram.ext import Application

TELEGRAM_TOKEN = "bot_token_here"
TELEGRAM_CHAT_ID = "telegram_chat_id_here"

async def work(application):
    while True:
        logging.info(f"=== There are: {threading.active_count()} threads. 1 ===")
        await application.bot.send_message(chat_id=TELEGRAM_CHAT_ID, text="test")
        logging.info(f"=== There are: {threading.active_count()} threads. 2 ===")
        await asyncio.sleep(5)

        threads = threading.enumerate()
        for thread in threads:
            try:
                logging.info(f"Thread name: {thread.name} - alive: {thread.is_alive()} - daemon: {thread.daemon}")
            except Exception as e:
                logging.error(f"Error: {e}")

def main()->None:
    application = Application.builder().get_updates_http_version('1.1').http_version('1.1').token(TELEGRAM_TOKEN).build()
    
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    loop.run_until_complete(work(application))
    loop.close()

if __name__ == "__main__":
    main()

输出如下：

2023-08-11 09:41:55,328 - root - INFO -  === There are: 1 threads. 1 ===
2023-08-11 09:41:55,804 - root - INFO -  === There are: 2 threads. 2 ===
2023-08-11 09:42:00,811 - root - INFO -  Thread name: MainThread - alive: True - daemon: False
2023-08-11 09:42:00,812 - root - INFO -  Thread name: ThreadPoolExecutor-0_0 - alive: True - daemon: True
2023-08-11 09:42:00,812 - root - INFO -  === There are: 2 threads. 1 ===
2023-08-11 09:42:01,057 - root - INFO -  === There are: 3 threads. 2 ===
2023-08-11 09:42:06,063 - root - INFO -  Thread name: MainThread - alive: True - daemon: False
2023-08-11 09:42:06,063 - root - INFO -  Thread name: ThreadPoolExecutor-0_0 - alive: True - daemon: True
2023-08-11 09:42:06,063 - root - INFO -  Thread name: ThreadPoolExecutor-0_1 - alive: True - daemon: True
2023-08-11 09:42:06,063 - root - INFO -  === There are: 3 threads. 1 ===
2023-08-11 09:42:06,286 - root - INFO -  === There are: 4 threads. 2 ===
...

等等...

如果我删除

await asyncio.sleep(5)

行，我会得到：

2023-08-11 09:32:50,957 - root - INFO -  === There are: 1 threads. 1 ===
2023-08-11 09:32:51,268 - root - INFO -  === There are: 2 threads. 2 ===
2023-08-11 09:32:51,268 - root - INFO -  Thread name: MainThread - alive: True - daemon: False
2023-08-11 09:32:51,268 - root - INFO -  Thread name: ThreadPoolExecutor-0_0 - alive: True - daemon: True
2023-08-11 09:32:51,268 - root - INFO -  === There are: 2 threads. 1 ===
2023-08-11 09:32:51,403 - root - INFO -  === There are: 2 threads. 2 ===
2023-08-11 09:32:51,403 - root - INFO -  Thread name: MainThread - alive: True - daemon: False
2023-08-11 09:32:51,403 - root - INFO -  Thread name: ThreadPoolExecutor-0_0 - alive: True - daemon: True
2023-08-11 09:32:51,403 - root - INFO -  === There are: 2 threads. 1 ===
2023-08-11 09:32:51,502 - root - INFO -  === There are: 2 threads. 2 ===

所以这次总是 2 个线程。

我需要我的

work

函数在下一次执行之前等待，但随后我得到了这个无限线程生成器...

我还测试了删除

send_message

行，并单独保留

asyncio.sleep(5)

，但它不会创建新线程，仅结合两个函数。

任何人都可以帮助我理解我做错了什么或者这是否是预期的？

Answer 1

回答我自己的问题...

经过进一步测试，问题似乎出在使用的Python版本（3.7）上。我升级到 3.11，问题现在消失了，它现在只创建了一个线程。