editl = tkinter. Entry(window, textvariable = str_
varl)
editl. pack ()
edit2 = tkinter. Entry(window, textvariable = str
一
var2)
edit2. pack () #
buttonl = tkinter.Button （window,text="+"，
command=buttonl click)
buttoni. pack ()
button2 = tkinter.Button （window,text="ー"，
command=button2_click)
button2. pack () #