error explanation - 'statInter' object has no attribute 'tk'

I am trying to create a simple timer in Python and am aiming to build the user interface using classes. I would like to use the classes to initialise user interface. Then in the main text of the body, I would like to add attributes using the .grid and .configure methods. But when I try to do this, the error: 'statInter' object has no attribute 'tk' appears.

I am a beginner in programming, but if I understand the error correctly the it results because the .grid and other Button methods are not inherited by my statInter (i.e. static interface) class. Is this correct? How do I solve this error? I trued inheriting the properties of Button class and even Tk class, but in the later case I get an infinite loop i.e. maximum recursion depth exceeded.

Thanks for your help

#This is a simple timer version

from tkinter import *

window = Tk()
window.title('Tea timer')
window.minsize(300,100)
window.resizable(0,0)

class statInter(Button,Entry):

    def __init__(self, posx, posy):
        self.posx = posx  # So the variables inside the class are defined broadly
        self.posy = posy

    def button(self):
        Button(window).grid(row=self.posx, column=self.posy)

    def field(self):
        Entry(window, width=5)

sth = statInter(1,2)
sth.grid(row=1, column = 2)

window.mainloop()