Python TkInter Object Oriented Template

TkInter-Template.py

#!/usr/bin/env python3
# -*- coding:UTF-8 -*-

"""
TODO: Documentation to here.
"""

from tkinter import *
from ui import Ui
import json, sys, os


class Window:
    def __init__(self, root, argv):
        self.root = root
        self.argv = argv
        self.gui = GUI(root, self)
        self.root.mainloop()

    def onclick(self):
        self.gui.button.config(text="OK")


if __name__ == "__main__":
    Window(Tk(), sys.argv[1:])

ui.py

from tkinter import *


class Ui:
    def __init__(self, root, meta_self):
        self.button = Button(
            master=root,
            text="Press",
            command=lambda: meta_self.onclick()
        )
        self.button.pack(expand=True)