for treatment in treament_list:
    label = ttk.Label(frames[treatment[1] - 1], text=treatment[0])
label.bind('<Enter>', lambda event, t=treatment: update_bottom_scroll_bar(
    text=t))
label.bind('<Leave>', lambda event: update_bottom_scroll_bar(text=
    'Default label text'))
Making a list of mouse over event functions in Tkinter