title: Insert multiple input in one entry Tkinter
body: <p>I got a task where I'm supposed to create a summation calculator using tkinter and I end up with this code below:</p>
  <pre><code>import tkinter as tk
  from tkinter import *
  
  window = Tk()
  window.geometry('300x250')
  window.title('Summation')
  
  insert_n = tk.Entry(window)
  insert_n.pack()
  
  def sum_input():
      sum_input = int(insert_n.get())
      print(sum(sum_input))
  
  button = tk.Button(window,text='Sum',command=sum_input)
  button.pack()
  
  window.mainloop()
  </code></pre>
  <p>What I'm trying to achieve is lets say when the user entered 1,2,3,4 in the entry where the sum of the input value will be printed out on my console after the 'Sum' button is pressed, so in this case the output should be 10.</p>
  <p>How do I do that?</p>