from Tkinter import *

class NextScreen():
        def __init__(self,root):
                self.Check1 = IntVar()
                self.Check2 = IntVar()
                self.space = Label(root , text = "\n Also select the classifier").grid(row = 0)
                self.C1 = Checkbutton(root, text = "C", variable

class Test:
    ....
    ....
class test:
    def __init__(self,root):
           ....
    def change(self):
           if(a==1): # any checking condition
               root.destroy()
               t1 = Tk()

 def __init__(self,root):
                self.CheckVar1 = IntVar()
                self.CheckVar2

class NextScreen():
        
        def __init__(self,root,val):
                self.CheckVar1 = IntVar()
                self.CheckVar2 = IntVar()
                self.label = Label(root,text = " \n Click on what do you wish to do \n ").grid(row = 0)
                self.calculate = Button(root,text = "CALCULATE THE THRESHOLDS").grid(row = 1,column = 0)

CheckVar1 = IntVar()
CheckVar2 = IntVar()
self.C1 = Checkbutton(root, text = "C Classifier", variable = CheckVar1, onvalue = 1, offvalue = 0, height=5,width = 20).grid(row=4)

class c1 :
    def __init__: