Telegram Message Listener - RuntimeError: Event Loop is closed

Question

I want to receive new messages from Telegram via a python script. I filter the message and then put out the result. But there is something wrong with the loop so I can't use this script in another because it always ends with this error. This is my Code:

import asyncio
import configparser
from telethon import TelegramClient, events

#Reading Config
config = configparser.ConfigParser()
config.read("config.ini")

#Setting configuration values
api_id = config["Telegram"]["api_id"]
api_hash = config["Telegram"]["api_hash"]

api_id = int(api_id)
api_hash = str(api_hash)

phone = config["Telegram"]["phone"]
username = config["Telegram"]["username"]


async def get_msg_async():
    client = TelegramClient("session_read", api_id, api_hash)
    user_input_channel = "https://t.me/+boLhJxP8JDU1NmVi"
    message_filter = "Coin is:"

    found = asyncio.get_event_loop().create_future()

    @client.on(events.NewMessage())
    async def new_message_listener(event):
        new_message = event.message.message
        channel = event.message.peer_id.channel_id
        if new_message.find(message_filter) != -1 and channel == 1717661228:
            search_index_coin = new_message.find("Coin is: ")
            coin = new_message[search_index_coin + 9 : search_index_coin + 14]
            if coin.find("\n") != -1:
                blank_index = coin.find("\n")
                coin = coin[:blank_index]
            if new_message.find("Projected Gain: ") != -1:
                search_index_gain = new_message.find("Projected Gain: ")
                gain = new_message[search_index_gain + 16 : search_index_gain + 20]
                if gain.find("-") != -1:
                    dash_index = gain.find("-")
                    gain = gain[:dash_index]
                elif gain.find("%") != -1:
                    percent_index = gain.find("%")
                    gain = gain[:percent_index]
                found.set_result({"coin": coin, "gain": gain})
            else:
                found.set_result({"coin": coin})
        else:
            print("Not found!")

    # start the client
    await client.start()
    # allow the client to run in the background and wait for
    # newMessageListener to provide the message
    return await found


def get_msg():
    asyncio.run(get_msg_async())


if __name__ == "__main__":
    msg = get_msg()
    print(msg)

When I get a new message I get a output with the right result but also the Error. How to fix this?

{'coin': 'BTC', 'gain': '600'}
Exception ignored in: <function _ProactorBasePipeTransport.__del__ at 0x000002640CC73E20>
Traceback (most recent call last):
  File "C:\Users\xamre\AppData\Local\Programs\Python\Python310\lib\asyncio\proactor_events.py", line 116, in __del__
    self.close()
  File "C:\Users\xamre\AppData\Local\Programs\Python\Python310\lib\asyncio\proactor_events.py", line 108, in close
    self._loop.call_soon(self._call_connection_lost, None)
  File "C:\Users\xamre\AppData\Local\Programs\Python\Python310\lib\asyncio\base_events.py", line 750, in call_soon
    self._check_closed()
  File "C:\Users\xamre\AppData\Local\Programs\Python\Python310\lib\asyncio\base_events.py", line 515, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed

Answer 1

This is actually a bug in asyncio on windows.

You can read about the details here if interested.

This was the code I was using at the top of all my projects:

# Windows Development Fix
# Big thanks to https://github.com/paaksing for this snippet!
# https://github.com/aio-libs/aiohttp/issues/4324
# http://www.apache.org/licenses/LICENSE-2.0
import platform
from functools import wraps
# Protected member is being patched as a bug fix.
# noinspection PyProtectedMember
from asyncio.proactor_events import _ProactorBasePipeTransport


def silence_event_loop_closed(func):
    """ This code serves to fix a crash that specifically happens on windows due to the aiohttp
    library using a different underlying mechanism on windows. See issue 4324 for more information."""

    @wraps(func)
    def wrapper(self, *args, **kwargs):
        """Wraps the incoming function with an exception handler"""

        try:
            return func(self, *args, **kwargs)
        except RuntimeError as e:
            if str(e) != 'Event loop is closed':
                raise

    return wrapper


if platform.system() == 'Windows':
    # Silence the exception here.
    _ProactorBasePipeTransport.__del__ = silence_event_loop_closed(_ProactorBasePipeTransport.__del__)


# End Windows Development Fix