Stopwatch.py

# Python program to illustrate a stop watch
# using Tkinter
#importing the required libraries
import tkinter as Tkinter

def stopwatch_tkinter():
	counter = -1
	running = False

	def counter_label(label):
		def count():
			if running:
				global counter

				# To manage the intial delay.
				if counter == -1:
					display = "Starting..."
				else:
					display = str(counter)

				label['text'] = display  # Or label.config(text=display)

				# label.after(arg1, arg2) delays by
				# first argument given in milliseconds
				# and then calls the function given as second argument.
				# Generally like here we need to call the
				# function in which it is present repeatedly.
				# Delays by 1000ms=1 seconds and call count again.
				label.after(1000, count)
				counter += 1

		# Triggering the start of the counter.
		count()

	# start function of the stopwatch
	def Start(label):
		global running
		running = True
		counter_label(label)
		start['state'] = 'disabled'
		stop['state'] = 'normal'
		reset['state'] = 'normal'

	# Stop function of the stopwatch
	def Stop():
		global running
		start['state'] = 'normal'
		stop['state'] = 'disabled'
		reset['state'] = 'normal'
		running = False

	# Reset function of the stopwatch
	def Reset(label):
		global counter
		counter = -1

		# If rest is pressed after pressing stop.
		if running == False:
			reset['state'] = 'disabled'
			label['text'] = 'Welcome!'

		# If reset is pressed while the stopwatch is running.
		else:
			label['text'] = 'Starting...'

	root = Tkinter.Tk()
	root.title("Stopwatch")
	root.iconbitmap("Computer_icon.ico")

	# Fixing the window size.
	root.minsize(width=250, height=70)
	label = Tkinter.Label(root, text="Welcome!", fg="black", font="Verdana 30 bold")
	label.pack()
	start = Tkinter.Button(root, text='Start',
						   width=15, command=lambda: Start(label))
	stop = Tkinter.Button(root, text='Stop',
						  width=15, state='disabled', command=Stop)
	reset = Tkinter.Button(root, text='Reset',
						   width=15, state='disabled', command=lambda: Reset(label))
	start.pack()
	stop.pack()
	reset.pack()
	root.mainloop()