How do you refresh a window in Tkinter

If I created Tkinter window with some text that filled the whole window and now wanted to replace the window with a new text, is there a way to refresh the window?

For Example:

    a= 100
    win= Tk() 
    win.geometry("500x300")
    while a > 0:
       if a%2 == 0:
           lbl = Label (win, bg = "purple")
           lbl.pack()
       else:
           lbl = Label (win, bg = "blue")
           lbl.pack()
       a= x-1

The problem with this code is that the Tkinter window does not refresh and just provides the end result instead of showing the开发者_如何学C windows changing colors. Thanks for the help!

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That is not the way to change UI states, because even if you refreshed the window it would be so quick you won't notice, instead change the state, wait some time and change the state again e.g. here I show how to animate color

from Tkinter import *

index = 0
def changeColor():
    global index
    if index%2==0:
        label.configure(bg = "purple")
    else:
        label.configure(bg = "blue")
    index+=1
    label.after(1000, changeColor)

root = Tk()
mainContainer = Frame(root)
label = Label(mainContainer, text="")
label.configure(text="msg will change every sec")
label.pack(side=LEFT, ipadx=5, ipady=5)
mainContainer.pack()
label.after(1000, changeColor)
root.title("Timed event")
root.mainloop()

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This Is How I Do To Update Data From Sql Server in tkinter GUI python3

from tkinter import *
import os
window=Tk()
window.geometry('300x300')

def update():
 window.destroy()
 os.system('test.py')
Button(window,text="Refresh",command=update)
window.mainloop()