import tkinter
import datetime

canvas = tkinter.Canvas(width=640, height=480)
canvas.pack()

t = datetime.datetime.now()
current_time = t.strftime("%H:%M:%S.%f")[:-5]
hour = t.hour
minute = t.minute
second = t.second
mc = t.microsecond
micro = mc/100000
print(current_time)

def tick():
    global current_time, micro, second, minute, hour
    micro += 1
    canvas.after(100, tick)
    if micro > 9:
        second += 1
        tick
    if second > 59:
        minute += 1
        tick
    if minute > 59:
        hour += 1
        tick
    if hour > 23:
        hour = 0
        tick

clock = canvas.create_text(320, 240, font="arial 72", text=current_time)
canvas.itemconfig(clock, text=current_time)

canvas.mainloop()