Скачать или смотреть Create Blinking Tkinter Windows in Python

Learn how to create two Tkinter windows in Python, where one window blinks open and closed at a set interval using effective coding practices.
---
This video is based on the question https://stackoverflow.com/q/65170922/ asked by the user 'Evan' ( https://stackoverflow.com/u/14775222/ ) and on the answer https://stackoverflow.com/a/65175468/ provided by the user 'acw1668' ( https://stackoverflow.com/u/5317403/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Create 2 tkinter windows one of which 'blinks' open and closed

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Create Blinking Tkinter Windows in Python

If you're diving into GUI programming with Python and Tkinter, you may want to create dynamic interfaces. A common fun challenge is to create two Tkinter windows, where one window blinks — opening and closing at set intervals — while the other remains open. This guide will guide you through addressing this challenge, share a solution, and explain the why behind it, ensuring you have a strong grasp of the concepts used.

The Problem

You want to create two Tkinter windows:

Win1: This window stays open constantly.

Win2: This window ‘blinks’, meaning it opens and closes repeatedly at a defined interval.

You started with some code, but encountered errors due to improper handling of window instances. Specifically, you were trying to reuse the same variable to reference multiple windows, which led to errors when attempting to destroy already closed windows.

Understanding the Previous Error

The error you faced is as follows:

[[See Video to Reveal this Text or Code Snippet]]

This occurred because you were using the win2 variable to hold references for all instances of the second window. When you destroyed the first instance of win2, the subsequent calls tried to destroy a window that no longer existed, leading to the exception.

Key Concepts:

Tk vs Toplevel: You can only have one instance of Tk in a single program. It's best practice to use Toplevel for additional windows.

Variable Scope: When using loops, ensure that variable references (like win2) are unique for each iteration or use function parameters to manage state.

The Solution

To achieve the desired blinking effect with correct management of window instances, we'll utilize the after() method correctly along with recursive function calls. Here's how you can do it:

Step-by-Step Code Explanation

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Code

Import the Tkinter Module: We import the module to use Tkinter functionalities.

Creating Win1: We create the first window instance using tk.Tk().

Creating the Blink Function:

The blink_window function takes two parameters:

win2 - the window to be created/destroyed,

n - the number of blinks remaining.

If a win2 exists, it is destroyed.

If n is still greater than 0, we create a new Toplevel window, and schedule the next call to blink_window after 300 milliseconds.

Starting the Process: We call blink_window() to initiate the blinking effect and win1.mainloop() to keep the first window open.

Conclusion

Creating a Microsoft Windows-like blinking effect with Tkinter might seem daunting, but with proper handling of window instances and a deep understanding of the interacting components, it's quite straightforward. By following the above steps, you've learned how to manage multiple window instances using Python’s Tkinter framework effectively.

Now it’s your turn! Try integrating additional features or modifying the blink interval to further customize your application. Happy coding!