I’m trying to close the first window as the second window opens. Both windows close, or the first window closes and the second window never opens.

This question has a similar problem but was solved by addressing the imported libraries: Tkinter is opening a second windows when the first one is closing

This question also has a similar problem, but the solution keeps all windows active/open all the time, but withdraws the windows from view/user interaction when they are not being used. I want a solution without keeping 23 windows open at the same time. Python tkinter cloase first window while opening second window

I don’t want to keep multiple windows open at the same time. What I am asking in this question is a MWE. So I’ve included only two windows in this question. My actual application has 23 windows in a tree-like structure.

quit and destroy both close the mainloop. Ideally, I’d use one mainloop and open and close windows as I need them rather than close one mainloop and sequentially open 22 other mainloops.

Here’s my code, which was taken from here https://www.pythontutorial.net/tkinter/tkinter-toplevel/

from tkinter import *
from tkinter import ttk


class Window(Toplevel):
    def __init__(self, parent):
        super().__init__(parent)


        self.geometry('300x100')
        self.title('Toplevel Window')

        ttk.Button(self,
                text='Close',
                command=self.destroy).pack(expand=True)


class App():
    def __init__(self, root):
        super().__init__()
        self.root = root

        root.geometry('300x200')
        root.title('Main Window')

        # place a button on the root window
        ttk.Button(root,
                text='Open a window',
                command=self.open_window).pack(expand=True)

    def open_window(self):
        window = Window(self.root)
        window.grab_set()
        self.root.quit()


if __name__ == "__main__":
    root = Tk()
    App(root)
    root.mainloop()

I added in self.destroy() in the function def open_window(self). I also tried root.quit(). Both will close both windows.

I adapted this script so that class App takes root as an argument, rather than being a subclass of tk.Tk.