Issue while importing variable from one file to other

[mamta_parida]

I created a GUI using tkinter having nine different classes and all classes are in one one script file. I'm getting issue when trying to use one variable define in one class function of a file and used in another file of a class but getting error like not able to import or global variable not define
I tried all ways to import module such as
Import X, from X import *, from X import X, from X import a,b,c and X = __import__()
Any solution to this issue will be appreciated