[Tkinter] Take the variable of a cursor class

[delcencen]

Hello, i try diffrent things beffor call your help but that doesn't work.
I would like to get the x value in my main code.

from tkinter import*
class CursseurBrightness(Frame):
    def __init__(self):
        Frame.__init__(self)
        def updateLabel(x):
            lab.configure(text='Curent value = ' + str(x))
        winCurs = Tk()
        Scale(winCurs,length=250,orient=HORIZONTAL,label ='Exposition :',troughcolor='dark grey',sliderlength=20,showvalue=10,from_=0,to=20,tickinterval=1,command=updateLabel).pack()
        lab=Label(winCurs)
        lab.pack()
        

cursBright=CursseurBrightness()
cursBright.mainloop()
brightness_factor0to20=cursBright

while True:


    print(brightness_factor0to20)

thanks for your help