I want to make a Timer, but display is 0:00:00.000000 how can change display is 0:00:00
import time, datetime
import tkinter as tk
import time, datetime
win = tk.Tk()
win.geometry('200x100+550+250')
win.title('Timer')
win.config(bg='#323232')
win.attributes('-topmos', 1)
start = datetime.datetime.now()
frame = tk.Frame()
lab = tk.Label(text='', bg='#000000', fg='#FFFFFF')
lab.pack()
def update():
dur = datetime.datetime.now() - start
lab.config(text=dur)
frame.after(20, update)
Start Button : when click button will start timer
St_button = tk.Button(text='Start', command=update)
St_button.pack()
frame.mainloop()