title: Tkinter Button still responds to click after being disabled and updated
body: <p>I want the button to start the command, then be disabled while executing and enabled again after the execution finished.</p>
  
  <p>When I click the button, it appears to be disabled and the command is executed. But when I click the button while it is disabled, the command is executed a second time after it finished the first execution. </p>
  
  <p>It seems like after the second click, the button is really disabled because I can click several times while it's disabled and it's only repeated once.</p>
  
  <pre><code>import tkinter as tk
  import time
  
  
  class Button:
      def __init__(self, master):
          frame=tk.Frame(master)
          frame.pack()
          self.button1=tk.Button(frame, text="Ready",bg="green", fg="white", command=self.click)
          self.button1.pack()
  
      def click(self):
          self.button1.config(bg="red", text="Busy", state="disabled")
          self.button1.update()
          doSth()
          self.button1.config(bg="green", fg="white", text="Ready", state="normal")
          self.button1.update()
  
  
  def doSth():
      time.sleep(3)
      print("done")
  
  
  root = tk.Tk()
  b = Button(root)
  root.mainloop()
  </code></pre>