Timer never updates when using `after`

Question

So I'm trying to make a countdown counter on tkinter that starts from 03:00 minutes and ends on 00:00, actively updated every second. At first I used a while loop with time.sleep() but it freezed my tkinter, so I tried to use tkinter after() method but without any success. What I'm trying to do is to start a timer from 03:00 minutes, goes down - 02:59, 02:58, 02:57,....,00:00 the timer is being represented using a tk.StringVar and should start just when the tkinter window open

This code I wrote raises a maximum recursion depth exception:

class BoggleGUI:
    def __init__(self):
        self.root = tk.Tk()
        self.root.title("Boggle Game")
        self.root.resizable(False, False)

        self.__sec = tk.StringVar()
        self.__sec_entry = tk.Entry(self.root, textvariable=self.__sec,
                                    width=2, font="Helvetica 14")
        self.__sec_entry.place(x=220, y=12.5)
        self.__sec.set("00")

        self.__mins = tk.StringVar()
        self.__mins_entry = tk.Entry(self.root, textvariable=self.__mins,
                                     width=2, font="Helvetica 14")
        self.__mins_entry.place(x=190, y=12.5)
        self.__mins.set("03")

        self.countdown_timer()

    def countdown_timer(self):
        times = int(self.__mins.get()) * 60 + int(self.__sec.get())
        if times > -1:
            minute, second = divmod(times, 60)
            self.__mins.set("{0:2d}".format(minute))
            self.__sec.set("{0:2d}".format(second))

            self.root.update()

            if times == 0:
                self.__sec.set('00')
                self.__mins.set('00')
            times -= 1
        self.root.after(1000, self.countdown_timer)

`self.root.after(1000, self.countdown_timer)`, don't call the method, you need to provide the method object — Matiiss, Jan 01 '22 at 21:38
I removed the parentheses from self.root.after(1000, self.countdown_timer()) and still doesn't work — PythonAddict, Jan 01 '22 at 21:43
I don't know what _doesn't work_ means, you btw haven't provided a [mre], does it still raise the same error? — Matiiss, Jan 01 '22 at 21:44
Does this answer your question? [Why is the command bound to a Button or event executed when declared?](https://stackoverflow.com/questions/5767228/why-is-the-command-bound-to-a-button-or-event-executed-when-declared) — Delrius Euphoria, Jan 01 '22 at 21:46
why do you have a `while` loop there? you yourself came to the conclusion that you can't use it — Matiiss, Jan 01 '22 at 21:47
I want the timer to start from 03:00 and go down 02:59, 02:58, 02:57,...,00:00 — PythonAddict, Jan 01 '22 at 21:47
I put a while loop to update the seconds and minutes every second — PythonAddict, Jan 01 '22 at 21:47
that is what the `after` "loop" is supposed to do, remove the `while` loop, also you should provide a [mre]. that `while` loop likely finishes in a few milliseconds — Matiiss, Jan 01 '22 at 21:47
Are you looking to make a timer? That goes from, say, 20 seconds to 0 every second? — Delrius Euphoria, Jan 01 '22 at 21:50
Yes, but not from 20 seconds to 0, but from 03:00 minutes to 00:00 — PythonAddict, Jan 01 '22 at 21:52
times is 180 at the beginning (3 minutes = 60*3 seconds), and every second i substract 1 from times untill it reaches 0 — PythonAddict, Jan 01 '22 at 21:54

Iliya · Accepted Answer · 2022-01-01T22:00:04.940

You need to move times =- 1 above:

            minute, second = divmod(times, 60)
            self.__mins.set("{0:2d}".format(minute))
            self.__sec.set("{0:2d}".format(second))

otherwise the update of the time does not happen and realign self.root.after(1000, self.countdown_timer)

Change the function to this and it will work:

    def countdown_timer(self):
        times = int(self.__mins.get()) * 60 + int(self.__sec.get())
        if times > 0:
            times -= 1

            minute, second = divmod(times, 60)
            self.__mins.set("{0:2d}".format(minute))
            self.__sec.set("{0:2d}".format(second))

            self.root.update()

            if times == 0:
                self.__sec.set('00')
                self.__mins.set('00')
            self.root.after(1000, self.countdown_timer)

I have edited the response, also change if times > -1: to if times > 0: for when it reaches zero, otherwise goes negative.

score 0 · Answer 2 · edited Jan 01 '22 at 21:55

0

You can also use the threading library. And create a timer function with the sleep method and after utilize

threading.Thread(target=timer).start()

You can read more in the library documentation.

edited Jan 01 '22 at 21:55

Delrius Euphoria

14,910
3
15
46

answered Jan 01 '22 at 21:51

Snap

36
3

it may not be clear to people reading this what exactly they are supposed to do, can you please add more explanation – Matiiss Jan 01 '22 at 21:52

score -3 · Answer 3 · answered Jan 01 '22 at 21:45

-3

Maybe try setting the recursion limit to an higer limit(default is set to 1000).

import sys
sys.setrecursionlimit(your_limit)

Let me know if this solve can halp.

answered Jan 01 '22 at 21:45

Angelo Ascione

1

2

This unfortunately doesn't answer the OP's question, and doesn't address their problem. Setting the recursion limit higher is just going to prolong the death of the program, and the error messages. – Sylvester Kruin Jan 01 '22 at 23:28

Timer never updates when using `after`

3 Answers3