[Tkinter] Tk window not displaying until loop has completed

[Ganga]

Hi, I'm new to python and Tkinter (as in two days in!), so appreciate this may be a pretty obvious mistake I'm making. Why is it that if I have a loop(s) in my code that the Tk window doesn't display until the loop(s) has gone through all it's iterations. What I want is for the window to display at the start so that I can then view the result of each iteration in the window. Here's a small sample program to show what I mean. If you run it yourself you'll see the lag before the window opens.

from tkinter import *

root = Tk()

for column in range (0, 50):
    
    for row in range (0, 40):
        
        #calculate next number from row and column
        number = row+(column*40)
        #create label
        myLabel = Label(root, text=str(number))
        #display label
        myLabel.grid(row=row, column=column)
    
root.mainloop()