Programma 1

#заготовка для калькулятора
from tkinter import *

root = Tk()

A = Entry(width=20)
B = Entry(width=20)

btn_sum = Button(text="+")

Lbl = Label(bg='black', fg='white', width=20)


def summa(event):
    a = int(A.get())
    b = int(B.get())
    Lbl['text'] = str(a + b)


btn_sum.bind('<Button-1>', summa)

A.pack()
B.pack()

btn_sum.pack()

Lbl.pack()

root.mainloop()