How to start a background task?

Question

Python

Hello guys, who can explain on the fingers how to start a background task? There is a bot on aiogram, when commanded, it launches the parser:

@dp.message_handler(Text(equals='Запуск парсера '))
async def accounts(message:types.Message):
    await message.bot.send_message(message.from_user.id, "запускаю парсер")
    await applications_parser.main(message = message)

main

async def main(message)-> None:
    user_id = message.chat.id
    user_agent = FakeUserAgent().random
    data = BotDB.get_account(user_id=user_id)
    for row in data:
        login_n = row[2]
        password_n = row[3]
    parser = Parser( login = login_n ,user_id=user_id, password = password_n, user_agent=user_agent)
    parser.get_first_start_parser()
    await parser.get_update_aplications()

Then the bot starts troiting and can process commands for a long time, how to fix this? Since the parser works constantly updating information every 30 seconds. If possible, please write on your fingers. And I've been scratching my head for a day now

Answer 1

When you do an await, you are saying "stop this coroutine, wait until the operation after the await finishes, then continue". While one coroutine is stopped, others can run. In general, read about how an asynchronous program works.
If you need to run a coroutine without waiting for it to complete, asyncio.create_task() is the way to go .
It should be understood that the code that you run through asyncio.create_task() must also be asynchronous! If you wrap an ordinary synchronous call in a coroutine and run it via create_task(), there will be no miracle - the bot will still stand up until the call ends.
So take a good look at your parser - if it's based on a synchronous library like requests, rewrite it to aiohttp.