Solution Exercise 195: graphical app in python tkinter that calculate the sum 1+2+..+n

Exercise 195

Create a graphical application in Python Tkinter that asks the user to enter an integer N and displays them the value of the sum "1 + 2 + ... + N" as shown in the figure below:

Solution

from tkinter import *

def action():
    # getting value of entryNumber
    N = int(entryNumber.get())
    # initialize sum 
    sum = 0
    for i in range(1 , N + 1):
        sum = sum + i
    # display the sum "1 + 2 + 3 + ... + N"  in label result
    lblResult['text'] = "The sum is  1 + 2 + 3 + ... + " + str(N) + " = " + str(sum)
    
root = Tk()
root.geometry("450x150")
 
# creating label and entry text for number N
lblNumber  = Label(root , text = "Enter value of integer N  : ")
lblNumber.place( x = 20 , y = 20)
entryNumber = Entry(root)
entryNumber.place( x = 200 , y = 20 , width = 240)

# creating label to display result
lblResult = Label(root , text ="")
lblResult.place(x = 200 , y = 50 )

# creating button to perform the action
btnValidate = Button(root, text = " Validate" , command = action)
btnValidate.place(x = 200 , y = 90 , width = 240)

root.mainloop()