title: Change tkinter entry widget multiple times after pressing a button
body: <p>I have a tkinter Entry widget and when a user presses a button the contents update:</p>
  
  <pre><code>from tkinter import *
  window = Tk()
  
  def abcdef(num):
      ent.config(state=NORMAL)
      ent.delete(0, 'end')
      ent.insert(0, num)
      ent.config(state = "readonly")
      print(num) #Just to check the code is being run
  
  def changeEntry():
      for j in range(3):
              ent.after(1000, abcdef(j))
  
  
  
  ent = Entry(widow, text="", state = "readonly", readonlybackground="white", font = "20")
  ent.grid(row = 0, column = 0, columnspan = 3, sticky = "E")
  
  btn = Button(window, text="Button", command=changeEntry)
  btn.grid(row = 1, column = 0, sticky = "NESW", pady = 10, padx = 10)
  
  window.mainloop()
  </code></pre>
  
  <p>When I press the button the window freezes for 3 seconds and then just displays the final number. How can I make it so when the user presses the button, the entry changes every second instead of just freezing for 3 seconds and only displaying the final one?</p>
  
  <p>Thanks in advance</p>