A messagebox is a little popup showing a message. Sometimes it accompanied by an icon. Almost all the times, it interrupts what the user is doing.
The examples below show you how to create and use a messagebox with tkinter. The code shown here is for Python 3.x and newer. Older versions of Python import and use tkinter differently.
Python Desktop Apps with Tkinter
The messagebox comes in many variations. You can have an info message, warning message or an error message. All these message boxes have a title and message.
The example below shows a messagebox only if a button is clicked. This is similar to a real world scenario where a message box is shown when something goes wrong.