Tkinter Stop Mainloop, quit(). 22 Note: This is somewhat a follow-up on the question: Tkinter - when do I need to call mainloop? Usually when using Tkinter, you call Tk. The problem here is, each operation executes one by one. If you perform long-running operations directly in the main thread, your application will become unresponsive or “freeze” until the operation completes. Whenever user starts a task, I must have a emergency reset button, if pressed would restart the mainloop and immediately return to the "idle" state without the need to complete task. This article will show how to use threading alongside Tkinter to perform background tasks without disrupting the user experience. destroy () in a button. The only solution about closing a mainloop for Tkinter that i found on the internet, is by using . Now, I would like to implement a stop button, meaning that I would have a mainloop() for the GUI, and The quit method stops the Tkinter mainloop and is another way to exit a program. You have a conflict, if the core of your application hasalso a blocking loop that is waiting for some events. destroy (), otherwise your command line script will not continue executing code after mainloop (). In this tutorial, you'll learn how to execute a separate thread in a Tkinter program to make it more responsive. quit () or . When it does, I need to close the window. A little example Whenever user starts a task, I must have a emergency reset button, if pressed would restart the mainloop and immediately return to the "idle" state without the need to complete task. I observed at sometimes after I close the window using the X button, the I think my program does start mainloop, but closing the window doesn't stop mainloop. clock. It is the easiest module in creating a GUI application. So if you have a mainloop () of TKinter in a command line script, use root. res はじめに 前回の記事で、Tkinter GUIでスレッドを利用して、応答性をよくする方法を紹介しました。 今回は、このスレッドの動作を制御する方法をご紹介します。 やりたいこと 下記の図を見てみてください。 スタートボタンを押すと、数字がカウントされるGUIプログラムを I'm writing a slideshow program with Tkinter, but I don't know how to go to the next image without binding a key. mainloop() runs, runs, and keeps running, and the only thing it runs is the event handlers. Stop thread from tkinter mainloop Asked 3 years, 1 month ago Modified 3 years, 1 month ago Viewed 207 times In Tkinter, quit () and destroy () do different things. Tk() window. Contribute to serwy/tkthread development by creating an account on GitHub. I have the following problem: I would like to create a GUI with tkinter, that reacts to signals, sent from a socket. If I just do all my tkinter code in a normal file rather than a class, everything works the same but the mainloop also stops when I call destroy on root, and the program ends. id Discover how to effectively stop a countdown in Python's `Tkinter` GUI applications while still running the mainloop. @YeeHaw Almost all of the answers have a thread that is a function, in which all they need to do is stop the loop of the function using a boolean or a condition. Hello r/learnpython I'm currently building a holiday-package program, but I'm struggling on how to close a Tkinter window after the user have given…. Problem Formulation: When using Tkinter for building graphical user interfaces in Python, running long-running tasks can freeze the UI because Tkinter is not thread-safe. I tested this and it works for me (I am aware that TKinter is not intended to be used in such a design, nevertheless, it works) Till now, I used to end my Tkinter programs with: tk. Unlike root. quit () stops the currently running Tk event loop (the innermost mainloop or a nested modal loop), returning control to the Python code after mainloop. Tk. mainloop() will still be running in background if quit() command is executed. When we invoke the destroy () method with the tkinter window object, it terminates the mainloop process and destroys all the widgets inside the window. Reference Links: Tkinter Documentation Real Python: Python GUI Programming With Tkinter GeeksforGeeks: Python GUI – Tkinter Conclusion: Using threads in Tkinter is essential for preventing the main event loop from freezing and maintaining a responsive GUI. python 停止mainloop，#学习如何在Python中停止mainloop在学习PythonGUI编程时，经常使用到`Tkinter`库来创建图形界面。 为了使程序能够响应用户的输入和操作，通常需要运行一个叫做`mainloop`的事件循环。 mainloop() 方法在创建 GUI 界面中起着最重要的作用。 本教程描述了 mainloop() 方法的重要性，并试图了解该方法背后发生了什么。 Python 中的 Tkinter mainloop() mainloop() 事件就像一个 while 循环；这将继续运行，直到用户退出。 我们可以说 mainloop() 用作更新 GUI 的驱动 4. The mainloop is a built-in function in Tkinter that continuously listens for events and updates the GUI accordingly. I am writing a videoplayer with tkinter/python, so basically I have a GUI that can play a video. Understanding how the mainloop works in Tkinter is essential for creating responsive and interactive applications. It waits for events to occur, such as user interactions (clicks, key presses) or system events, and processes them accordingly. I have this script that execute a long running function out of/before the main class/loop in tkinter and there is a button i created to quit the program completely using root. Tk 以下のコードは、上のテキストボックスに入力した値をデータフレームB列にあるか判定し、ある場合は下のテキストボックスに出力し、なければエラーウィンドウを吐き出すスクリプトになります。 ここで質問な A Tkinter window that freezes right after you click a button is a rite of passage. Suppose we want to perform 4 operations simultaneously. Tkinter is an event-driven graphical interface, which means that it likes to use its own timing and hooks to get things done. To avoid this, you need to use threading to offload time-consuming tasks to separate threads. I am setting up a test bench that needs to have a stop button to end the current program and set everything back to the original state. Creating a GUI using tkinter is an easy task. mainloop() stops. Why? How can I get it to stop mainloop too? Easy multithreading with Python's Tkinter. py import tkinter as tk import threading import time def time_count (): global frame global stop_flag while not 9 See the answers to How can I make silent exceptions louder in tkinter which show how to hook a callback into tkinter. The way most people discover this is by trying to implement delays with time. I can't figure out how to accomplish this. Once a specific task is started, the user must complete it before doing something else ( for example starting a new task ). However, it does not necessarily destroy all the widgets immediately; any pending events might be processed before the program completely terminates. destroy() While destroy() command vanish out root. self. I have made a simple "test" program to show exactly what I mean: You stop the mainloop with the command root. The mainloop () keeps the application running until the user closes the window or the program explicitly calls the quit () method. Can you describe what your program is meant to do? For simple user input I'd recommend you use the easygui module instead of creating your own. Tkinter mainloop() in Python Tkinter mainloop() Blocking in Python Tkinter mainloop() Non-Blocking in Python Tkinter is known as a popular module that is written in Python. This guide includes examples for easy understanding stop = tk. Jan 24, 2026 · A Tkinter window that freezes right after you click a button is a rite of passage. It keeps the window open, waits for user actions (like mouse clicks or key presses), and processes events until the window is closed. In my case waiting for input from a bluetooth device. e root. destroy(), after calling root. I tried to use quit() and destroy() but both just close the window. This is NOT a duplicate of Python tkinter mainloop not quitting on closing the window I have an app that builds on tkinter. Although I am a kind of experimented programmer in other languages, I am very new in Python. It’s less commonly used but can be handy when dealing with multiple windows or when you need to stop the mainloop without destroying widgets. report_callback_exception. destroy() but it close In this article, we will explore different methods to close a Tkinter window in Python 3. Doing root. The Problem: Freezing Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more. Since it did work as normal before I added an after loop, I assume the after is the problem. I have made a simple "test" program to show exactly what I mean: root. quit() method is used to stop the Tkinter mainloop. 调用主循环，显示窗口，同时开始tkinter的事件循环。 mainloop方法最后执行，将标签显示在屏幕，进入等待状态（注：若组件未打包，则不会在窗口中显示），准备响应用户发起的GUI事件。 在mainloop函数中，tkinter内部会监控这些事件，如键盘活动，鼠标单击等。 Learn how to cancel scheduled functions in Python Tkinter using `after_cancel()`, `after()`, and stored IDs. This article delves into the intricacies of Tkinter's mainloop, exploring its purpose, operation, and impact on GUI applications. The method mainloop has an important role for TkInter, it is waiting for events and updatingthe GUI. mainloop() i. mainloop () Example: This example creates a basic Tkinter window and starts the event loop. res A few months ago I watched a perfectly functional Tkinter app look “broken” on a coworker’s laptop. quit() The above line just Bypasses the root. after_cancel (id) Cancels an alarm callback. The mainloop is not a formality; it’s the coordinator that decides when your widgets redraw, when callbacks fire, […] How to break out of tkinter mainloop? I have a program that loads a tkinter window and at the same time waits for the user to click the mouse. Explore the nuances of Tkinter's mainloop and discover effective coding strategies to enhance your GUI applications. While Creating a GUI there will be a need to do multiple work/operation at backend. There are many visual elements that we can create and visualize. Here we discuss How the mainloop works in Tkinter and Examples along with the codes and outputs. Till now, I used to end my Tkinter programs with: tk. If you ship desktop tools (internal […] Tkinter, however, hogs the time for its own event loop, and so his code won't run. When debugging the program I can see it stops at the mainloop which makes sense. Bonus One-Liner Method 5: Use quit() as an alternative to destroy() The quit() method terminates the mainloop and is an alternative to destroy(). mainloop to run the event loop and ensure that events are properly processed and windows remain interactive without blocking. quit () and not root. Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more. quit(), the application is still intact, and you can perform additional actions or restart the mainloop if desired. title = "Game" tk. The mainloop is not a formality; it’s the coordinator that decides when your widgets redraw, when callbacks fire, […] Discover how to effectively stop a countdown in Python's `Tkinter` GUI applications while still running the mainloop. rowconfigure(0, @citizen2077 Adding a handler would be the first step to define what happens if the root is closed using the window manager, but you can also use a flag to communicate the thread that it should stop its execution. My Tkinter looks as follows: window = tk. What I thought was that you destroy the window then un-destroy it but apparently there is no un- Learn how to cancel scheduled functions in Python Tkinter using `after_cancel()`, `after()`, and stored IDs. The quit method stops the Tkinter mainloop and is another way to exit a program. after() works fine. I'm new to Python and even more so to tkinter, and I decided to try to create a start and stop button for an infinite loop through Tkinter. The first portion of the game is asking if one wants to play. mainloop() Here we have the same code but with the ability to cancel our loop with the after_cancel method of tkinter. Mar 19, 2025 · Python Tkinter Mainloop The Tkinter mainloop () is an infinite loop that runs in the background of your Python GUI application. But in Tkinter's mainloop, I am not finding a way to do this. The root cause was simple: the window was sized and positioned as if every user had the same display. This guide includes examples for easy understanding Learn how to create a Python program using Tkinter to build a timer application. What Mar 7, 2024 · The root. I have been trying to do a very simple thing that is to quit the mainloop after starting. pack() tick() root. Nothing crashed, no stack trace, no missing dependency—yet the UI was half off-screen. tkinterを使って1秒毎に数値をprintするプログラムを作っています。 Web上に、以下のようなコードがありました。 ・GUItest1. But I don't want the user to close the window manually, the window should be closed automatically every x second in order to be able to display a new window with updated information. after() is the designed, intended way to time events within a Tkinter GUI - it works, and works well. root. alarm = self. destroy() as it will it stop the mainloop ()`. For example, I would like to be able to terminate the application, when an end s @YeeHaw Almost all of the answers have a thread that is a function, in which all they need to do is stop the loop of the function using a boolean or a condition. mainloop (), or nothing would show up! See example: from Tkinter import * import random import time tk = Tk () tk. Python with tkinter is the fastest and easiest way to create the GUI applications. Is there a way to have his code run alongside the mainloop (without multithreading, it's confusing and this should be kept simple), and if so, what is it? I want to debug my program and i want to freeze the window by stopping mainloop but without closing the window. I was trying to avoid threading but I do not think it is pos How do I stop tkinter after function? Asked 13 years, 11 months ago Modified 4 years, 5 months ago Viewed 40k times I am wondering on how I can create a restart button that once clicked, can restart the entire script. You dont need to global the alarm inside a class. Tkinter destroy () method is mainly used to kill and terminate the interpreter running in the background. mainloop () The mainloop () method starts the event loop of a Tkinter application. But this method is blocking the code after it. If I put it in a class, however, mainloop doesn't stop in spite of the window being destroyed. Button(root, text='Stop it!', command=stop) stop. So as you just want to quit the program so you should use root. It provides a powerful object-oriented interface to the Tk GUI toolkit. 2. I’ve shipped that bug, watched the spinner stop, and realized I had blocked the very loop that makes the GUI breathe. Unfortunately, once I click start, it won't allow me to c Tkinter applications are single-threaded, meaning that all GUI updates and event handling occur within the main thread. Here’s an example: Guide to Tkinter mainloop. sleep() (spoiler: it doesn't work). This example as well as my actual program runs in recursive mode to make use of tkinter mainloop and after method. It seems that Jul 23, 2025 · Tkinter is the standard GUI (Graphical User Interface) library for Python. I am attempting to construct a simple game using the Tkinter GUI. This program starts a countdown when a 'Start' button is clicked and stops when a 'Stop' button is clicked. Below is the syntax: root. import os, sys import Tkinter import Image, ImageTk import time root = Tkinter. However, when the mainloop is running, I am not not sure how can I interrupt the task and stop it. The Tkinter mainloop Before diving into window closing methods, it is crucial to understand the concept of the Tkinter mainloop. idsd, 6qjwo, 9vbkcg, aygsk6, 93jok, qaqsq, bbwnwr, trzawu, y7gq, tdxo,