Using the Mouse Wheel with Tkinter (Python)

1. # explore the mouse wheel with the Tkinter GUI toolkit
2. # Windows and Linux generate different events
3. # tested with Python3.0
4.  
5. import tkinter as tk
6.  
7. def mouse_wheel(event):
8. global count
9. # respond to Linux or Windows wheel event
10. if event.num == 5 or event.delta == -120:
11. count -= 1
12. if event.num == 4 or event.delta == 120:
13. count += 1
14. label['text'] = count
15.  
16. count = 0
17. root = tk.Tk()
18. root.title('turn mouse wheel')
19. root['bg'] = 'darkgreen'
20.  
21. # with Windows OS
22. root.bind("", mouse_wheel)
23. # with Linux OS
24. root.bind("", mouse_wheel)
25. root.bind("", mouse_wheel)
26.  
27. label = tk.Label(root, font=('courier', 18, 'bold'), width=10)
28. label.pack(padx=40, pady=40)
29.  
30. root.mainloop()