old_contents: import tkinter as tk
  
  # This class defines a Square, just a clickable canvas which shows a nought or cross when clicked
  class Square(tk.Canvas):
  	def __init__(self, master=None, width=None, height=None):
  		super().__init__(master, width=width, height=height)
  		self.bind("<Button-1>", self.tic)
  		self.bind("<Button-2>", self.tac)
  	
  
  	def tic(self, event):
  		""""This will draw a cross on the selected Square."""
  		self.create_line(30, 30, 170, 170)
  		self.create_line(30, 170, 170, 30)
  
  	def tac(self, event):
  		""""This will draw a nought on the selected Square."""
  		self.create_oval(30, 30, 170, 170)
  
  root = tk.Tk()
  root.title("Tic Tac Toe")
  
  NW = Square(master=root, width=200, height=200)
  NW.grid(row=0, column=0)
  
  N = Square(master=root, width=200, height=200)
  N.grid(row=0, column=1)
  
  NE = Square(master=root, width=200, height=200)
  NE.grid(row=0, column=2)
  
  W = Square(master=root, width=200, height=200)
  W.grid(row=1, column=0)
  
  C = Square(master=root, width=200, height=200)
  C.grid(row=1, column=1)
  
  E = Square(master=root, width=200, height=200)
  E.grid(row=1, column=2)
  
  SW = Square(master=root, width=200, height=200)
  SW.grid(row=2, column=0)
  
  S = Square(master=root, width=200, height=200)
  S.grid(row=2, column=1)
  
  SE = Square(master=root, width=200, height=200)
  SE.grid(row=2, column=2)
  
  root.mainloop()
  
new_contents: import tkinter as tk
  
  # This class defines a Square, just a clickable canvas which shows a nought or cross when clicked
  class Square(tk.Canvas):
  	def __init__(self, master=None, width=None, height=None):
  		super().__init__(master, width=width, height=height)
  		self.bind("<Button-1>", self.tic)
  		self.bind("<Button-2>", self.tac)
  		self.config(highlightbackground="Black")
  		self.config(highlightthickness=1)
  	
  
  	def tic(self, event):
  		""""This will draw a cross on the selected Square."""
  		self.create_line(30, 30, 170, 170)
  		self.create_line(30, 170, 170, 30)
  
  	def tac(self, event):
  		""""This will draw a nought on the selected Square."""
  		self.create_oval(30, 30, 170, 170)
  
  root = tk.Tk()
  root.title("Tic Tac Toe")
  
  NW = Square(master=root, width=200, height=200)
  NW.grid(row=0, column=0)
  
  N = Square(master=root, width=200, height=200)
  N.grid(row=0, column=1)
  
  NE = Square(master=root, width=200, height=200)
  NE.grid(row=0, column=2)
  
  W = Square(master=root, width=200, height=200)
  W.grid(row=1, column=0)
  
  C = Square(master=root, width=200, height=200)
  C.grid(row=1, column=1)
  
  E = Square(master=root, width=200, height=200)
  E.grid(row=1, column=2)
  
  SW = Square(master=root, width=200, height=200)
  SW.grid(row=2, column=0)
  
  S = Square(master=root, width=200, height=200)
  S.grid(row=2, column=1)
  
  SE = Square(master=root, width=200, height=200)
  SE.grid(row=2, column=2)
  
  root.mainloop()
  
subject: Add a border to all Squares