from tkinter import *
window = Tk()
x = Entry(width=20)
y = Entry(width=20)
b = Button(text="+")
z = Label(bg='black', fg='white', width=20)
 
def strToSortlist(event):
    x1 = int(x.get())
    y1 = int(y.get())
    z1=x1+y1
    z['text'] =str(z1)
 
b.bind('<Button-1>', strToSortlist)
 
x.pack()
y.pack()
b.pack()
z.pack()
window.mainloop()