I am trying to make a tkinter application which doesn't close everything (other windows) when the first window (root) is closed. I have tried to use Toplevel() which works perfectly for pop-up windows in other programs but not for making a base level.
from tkinter import *
top = Toplevel(bg='red')
top.mainloop()
I don't know if this is possible or I don't know if I can change the Tk()'s properties to make it so it doesn't shut all other windows down.
There are two windows getting displayed because when a tkinter widget is created, it forces a Tk instance to be created as well, and every widget, unless a parent is explicitly passed, is a child to that automatically created Tk instance. So your code essentially mimics the following code:
from tkinter import *
root = Tk()
top = Toplevel(root, bg='red')
root.mainloop()
Now there are some ways to work around that for the behavior you want, one is to hide the actual Tk instance:
import tkinter as tk
root = tk.Tk()
root.withdraw()
top = tk.Toplevel(root, bg='red')
#to display root window again
#root.iconify()
#root.deiconify()
root.mainloop()
Another way would be to overrule the deletion of the root itself, but I doubt that's actually what you want:
import tkinter as tk
def callback():
print("Won't close")
root = tk.Tk()
root.protocol("WM_DELETE_WINDOW", callback)
root.mainloop()