Encapsulation is a major strength in any programming language, enabling us to program using OOP. Python is both OOP as well as procedural. We can create global variables that are localized to the module they reside in. They are global only to this module, which is one form of encapsulation. Why do we want this? Because as we add more and more functionality to our GUI, we want to avoid naming conflicts that could result in bugs in our code.
Note
We do not want naming clashes creating bugs in our code! Namespaces are one way to avoid these bugs, and in Python, we can do this by using Python modules (which are unofficial namespaces).
We can declare module-level globals in any module just above and outside functions.
We then have to use the global Python keyword to refer to them. If we forget to use global in functions, we will accidentally create new local variables. This would be a bug and something we really do not want to do.