How to access a button inside of a class in tkinter - python-3.x

Question

I'm using Python 3.8.0 and Tkinter 8.6.
I'm trying to access button one through the button.config method but I don't know how to access the button outside the class.
I tried assigning a name to button one and then trying app.name.config() but it didn't work and Python didn't recognize the name.
import tkinter as tk
from tkinter import font
class Application(tk.Frame):
def __init__(self, master=None):
tk.Frame.__init__(self, master)
self.grid()
self.theWidgets()
def theWidgets(self):
self.one = tk.Button(self, text='New Game',command=onePressed())
self.one.grid(row=0,column=0,padx=100)
self.two = tk.Button(self, text='Load Game')
self.two.grid(row=1,column=0,padx=100,pady=10)
self.three = tk.Button(self, text='Quit', command=self.quit,anchor=tk.W,font='Helvetica 18 bold')
self.three.grid(row=2, column=0, padx=100, pady=10)
app = Application()
def onePressed():
#change state of button one to tk.DISABLED
app.mainloop(
)

Answer 1

Code that controls the internal state of a class member (e.g. a button) normally belongs inside the class.
The actions of a button press should be defined as part of your class.
(As with anything, there are occasionally exceptions but for now follow the above).
For more details, see en.wikipedia.org/wiki/Encapsulation_(computer_programming).
All you need to do in your example is move the button press function inside your class and then associate it with your button (in the same way you associated quit with button 3).
import tkinter as tk
from tkinter import font
class Application(tk.Frame):
def __init__(self, master=None):
tk.Frame.__init__(self, master)
self.grid()
self.theWidgets()
def theWidgets(self):
self.one = tk.Button(self, text='New Game', command=self.onePressed)
self.one.grid(row=0,column=0,padx=100)
self.two = tk.Button(self, text='Load Game')
self.two.grid(row=1,column=0,padx=100,pady=10)
self.three = tk.Button(self, text='Quit', command=self.quit, anchor=tk.W, font='Helvetica 18 bold')
self.three.grid(row=2, column=0, padx=100, pady=10)
def onePressed(self):
self.one.config(state="disabled")
app = Application()
app.mainloop()