Tkinter toplevel class contains toplevel window which is a child window other than the main window. Whenever we create a toplevel window, it just appears above the main window along with the widgets defined in it.
To keep the window toplevel window focused, we can use grab_set() method. It always keeps the toplevel window above all the other windows.
Example
#Import the tkinter library
from tkinter import *
#Create an instance of tkinter frame
win = Tk()
win.geometry("700x350")
def open_win():
top = Toplevel(win)
top.geometry("700x250")
Label(top, text= "Hey Folks!", font= ('Helvetica 14 bold')).pack()
top.grab_set()
#Create a Label to print the Name
label= Label(win, text="Click the below Button to open the Popup", font= ('Helvetica 18 bold'))
label.pack(pady= 30)
#Create a Button
button= Button(win, text= "Click Me", command= open_win, font= ('Helvetica 14 bold'), foreground= 'OrangeRed3', background= "white")
button.pack(pady=50)
win.mainloop()Output
Running the above code will display a window that contains a button to open the Popup window.
Now, click the button to open a Popup window.
