1 min = 60 seconds 1 seconds = 100 centiseconds
We use the similar code as the Clock, there is a Lable (a textbox) called timeText, and we will update it every 1 centisecond, and increment our time sturcture by 1 as well. Take a look at the way it is designed.
# timer is a list of integer, in the following order timer = [minutes, seconds, centiseconds]Notice in the actual code it is initialized to 0,0,0. But it then created a problem of not being show as 00:00:00 as a normal stop watch would. One way to get around this is to use the string's format.() function.
pattern = '{0:02d}:{1:02d}:{2:02d}' timeString = pattern.format(timer[0], timer[1], timer[2]){0:02d}, the first 0 means which parameter in the format() function call, 02d means, it is expecting an integer of length 2, the 02 means it is padding with leading zeros infront of it. Take note of this feature, as it is really powerful, you can mix and match different parameters, instead of {0} {1} {2}, you can do creative things like {2} {1} {1} {2} {0}, (such as different order, multiple use of the same varaible, etc).

The following program contains 4 buttons (start, pause, reset, quit). Which they do what they are named after respectly. The reset function work both running and paused clock. Maybe it is a good idea to add a time lap feature?
import Tkinter as tk # Note: Python 2.6 or higher is required for .format() to work def update_timeText(): if (state): global timer # Every time this function is called, # we will increment 1 centisecond (1/100 of a second) timer[2] += 1 # Every 100 centisecond is equal to 1 second if (timer[2] >= 100): timer[2] = 0 timer[1] += 1 # Every 60 seconds is equal to 1 min if (timer[1] >= 60): timer[0] += 1 timer[1] = 0 # We create our time string here timeString = pattern.format(timer[0], timer[1], timer[2]) # Update the timeText Label box with the current time timeText.configure(text=timeString) # Call the update_timeText() function after 1 centisecond root.after(10, update_timeText) # To start the kitchen timer def start(): global state state = True # To pause the kitchen timer def pause(): global state state = False # To reset the timer to 00:00:00 def reset(): global timer timer = [0, 0, 0] timeText.configure(text='00:00:00') # To exist our program def exist(): root.destroy() # Simple status flag # False mean the timer is not running # True means the timer is running (counting) state = False root = tk.Tk() root.wm_title('Simple Kitchen Timer Example') # Our time structure [min, sec, centsec] timer = [0, 0, 0] # The format is padding all the pattern = '{0:02d}:{1:02d}:{2:02d}' # Create a timeText Label (a text box) timeText = tk.Label(root, text="00:00:00", font=("Helvetica", 150)) timeText.pack() startButton = tk.Button(root, text='Start', command=start) startButton.pack() pauseButton = tk.Button(root, text='Pause', command=pause) pauseButton.pack() resetButton = tk.Button(root, text='Reset', command=reset) resetButton.pack() quitButton = tk.Button(root, text='Quit', command=exist) quitButton.pack() update_timeText() root.mainloop()