I was creating a Telegram Bot that takes care of scraping on Amazon after receiving a URL via chat. Although it performs this task very well, I cannot handle the case in which the bot received a text that does not fall within the “allowed commands”; in fact, what I wanted it to accept are /start, /stop and a properly formatted URL. I had tried to insert an additional Handler that filtered the messages, but without success. Ultimately I would like any text outside of start, stop, and a URL to be responded to with an error message, such as “SEND ME A URL PLEASE”.

A further problem is that having declared the global variable bot_is_running, the bot appears to be active even before clicking on /start. How can I solve it?

Finally, would it be possible to know how to actually shut down the bot (apart from CTRL+C) and then whether it is possible to restart it from the chat itself, taking into account that it is running on the console of a virtual machine running Ubuntu?

I leave the code I have written so far to understand the structure used.

load_dotenv()

bot_is_running = True

authorized_users = []


async def start(update: Update, context: ContextTypes.DEFAULT_TYPE):

    global bot_is_running

    user_id = update.effective_user.id

    if user_id not in authorized_users:

        await update.message.reply_text("ACCESS DENIED")

        return

    bot_is_running = True

    await context.bot.send_message(chat_id=update.effective_chat.id, text="WELCOME!")



async def stop(update: Update, context: ContextTypes.DEFAULT_TYPE):

    global bot_is_running

    user_id = update.effective_user.id

    if user_id not in authorized_users:

        await update.message.reply_text("ACCESS DENIED")

        return

    bot_is_running = False

    await update.message.reply_text("THE BOT HAS BEEN TURNED OFF..")

    await context.application.stop()



async def stopped_message(update: Update, context: ContextTypes.DEFAULT_TYPE):

    global bot_is_running

    if not bot_is_running:

        await update.message.reply_text("THE BOT IS OFF.")



def main():

    app = ApplicationBuilder() 

        .read_timeout(100) 

        .write_timeout(100) 

        .token(os.environ["TG_BOT_TOKEN"]) 

        .build()

    app.add_handler(CommandHandler("start", start))

    app.add_handler(CommandHandler("stop", stop))

    app.add_handler(MessageHandler(filters.TEXT & (filters.Entity("url") | filters.Entity("text_link")), url_received))

    app.add_handler(MessageHandler(filters.TEXT, stopped_message))

    app.run_polling()


if __name__ == '__main__':

    main()