text: import tkinter as tk
  class Application(tk.Frame):
      
      on_hit = False
      
      def __init__(self, master=None):   
          tk.Frame.__init__(self, master)
          self.pack()
          self.var = tk.StringVar()
          self.createWidgets()
          
      def createWidgets(self):
          self.lable = tk.Label(self, textvariable=self.var, bg='green', font=('Arial', 12), width=15, height=2)
          self.lable.pack()
          self.btnHit = tk.Button(self, text="hit me", command=self.btdown)
          self.btnHit.pack()
          
      def btdown(self):           
          if self.on_hit == False:
              self.on_hit = True
              self.var.set('you hit me')
          else:
              self.on_hit = False
              self.var.set('')
          
  root = tk.Tk()
  root.title('my window')
  root.geometry('200x100')
  app = Application(master=root)  
  app.mainloop()
  