如何创建带验证的计时器（python + telegram）

Question

I am creating a telegram bot. There is a need to create a timer when you click on the button. In the example, this is the button: "Hero". How to make sure that the timer is not re-created when the same button is clicked.

@bot.message_handler(content_types=['text'])
def buttons(message):
    if message.chat.type == 'private':
        if message.text == 'Hero':
            def hello():
                print ('hello')

            t = threading.Timer(4, hello)

            if t.is_alive():
                print('wait to end')
            else: 
                t.start()
                print('timer is up')
        else:
            bot.send_message(message.chat.id, 'default1')
    else:
        bot.send_message(message.chat.id, 'default2')

#RUN
bot.polling(none_stop=True)

If I create a timer before processing the button, I get:

threads can only be started once

Answer 1

One of the idea is to use a global list

Initialize a list globally on top of the file.

CACHE=[]

Create a timer free function.

def free_user(t: Timer, user_id): # here t is Timer
    t.is_alive ... wait for the timer to end
    if user_id in CACHE:
         CACHE.remove(user_id)

On the handler, check if the user id is in the CACHE list

-> on button click

if user_id in CACHE:
    # already clicked user
    callback.answer("dude please wait")
else:
    # new user going to click for the first time
    global CACHE
    CACHE.append(user_id)
    free_user(timer....., user_id)