from tkinter import *
cal = "1"
def plusun(choix):
    global x
    global cal
    cal = str(cal) + str(choix)
    x.set(cal)
    
fen = Tk()
fen.title ("CALCULATRICE")

x = StringVar()
x.set("")

b1 = Button(fen,text = "petit 1", command = lambda: plusun("+"))
b1.grid( row= 0, column = 0)

f1 = Label(fen, textvariable = x)
f1.grid(row=1, column = 0)

gn = Tk()
gn.title ("CALCULATRICE")



b2 = Button(gn,text = "petit 2", command = lambda: plusun("+"))
b2.grid( row= 0, column = 0)

f2 = Label(gn, textvariable = x)
f2.grid(row=1, column = 0)