usernames.py

#!/usr/bin/env python3
from requests import post
from itertools import permutations
from string import ascii_lowercase, digits
import sys
from telethon import TelegramClient
from telethon.tl.functions.users import GetFullUserRequest
import asyncio


async def check_uname(username, client):
    try:
        temp = await client(GetFullUserRequest(username))
        # print(f'Username "{username}" is already taken')
        return

    except Exception as e:  # Заменяем на общее исключение
        print(f'Username "{username}" is free!')
        return


async def main():
    api_id = ""  # замени на свой
    api_hash = ""  # замени на свой
    client = TelegramClient('bot', api_id, api_hash)
    await client.connect()
    data = ascii_lowercase
    for attempt in permutations(data, r=4):
        r = "c" + "".join(attempt)
        async with client:
            await check_uname(r, client)


if __name__ == '__main__':  # Исправляем условие на вход в точку входа
    asyncio.run(main())