How to check the existence of chat_id when sending messages to a telegram bot?

Question

API

Hello! There is a telegram bot with n subscribers. The user's chat_id is written to the database when the bot is launched. It is required to send a message through the bot to all its subscribers. Sending is implemented through a loop in which the chat_id array is iterated over, sending is done through sendMessage(). If the array contains a chat_id whose user deleted this bot, then the loop is interrupted and the script stops working. Is it possible to check chat_id for binding to a bot, validity? Is it possible to intercept the event: bot deletion and delete the chat_id from the database accordingly?

Answer 1

When sending to such a chat, an exception occurs (the server returns an error), it must be caught and processed (delete this chat from the database, for example), then the script will not crash.

Answer 2

You can check the user for his presence in the bot only through the mailing list

count = 0
errors = 0

with sq.connect('base.db') as con:
    cur = con.cursor()
    cur.execute('''SELECT userid FROM users''')
    AllUser = cur.fetchall()
    
start_time = time.time()
for s in range(len(AllUser)):
    user_id = AllUser[count][0]
    try:
        bot.send_message(user_id, text='Текст для рассылки')
        count += 1
    except:
        count += 1
        errors += 1
        with sq.connect('base.db') as con:
            cur = con.cursor()
            cur.execute('''DELETE FROM users WHERE userid=?''', (user_id,)) # поймали ошибку на айди юзера и удалили его из базы
        
allusers = int(len(dataid))

goodresult = allusers - errors

goodresult = str(goodresult)

errors = str(errors)

times = "Время выполнения: %s сек." % round((time.time() - start_time))

sms = 'Рассылка завершена!'+'\n'+ 'Успешных результатов: '+goodresult+'\n'+'Ошибок: '+errors+'\n'+str(times)
bot.send_message(твой_айди, sms)# сюда придет уведомление о результатах рассылки

Answer 3

Thanks to all! I have a php bot.
Added an empty handler

function myCustomErrorHandler(int $errNo, string $errMsg, string $file, int $line) {}
set_error_handler('myCustomErrorHandler');

Then in the loop I used try catch

foreach($arUsers as $user) {
    try {
        $bot->send($user['chat_id']);
    } catch (Throwable $e) {
        $bot->run(
            "DELETE FROM `users` WHERE `chat_id` =  :chat_id",
            array('chat_id' => $user['chat_id']),
            PDO::FETCH_ASSOC
        );

        continue;
    }
}