Where is my python tkinter grid from this inheritance? - python-3.x

Question

this is a View and Controller part of a program that I am intending writing. My question is why I can't see my grid. My suspicion is that I am not inheriting correctly.
I think the problem is happening here:
"self.frame=Small_Frame(self)"
This is what I understand from my code. class Controller is inheriting from tk. class View is inheriting from tk.Frame. Up to here everything works.
class Small_Frame is my customer widget. The grid is just 12 instances of class Small_Frame using grid() method. I don't know why is it not showing up. Please help me understand. thank you.
import tkinter as tk
class View(tk.Frame):
def __init__(self, parent, controller):
tk.Frame.__init__(self, parent, bg= "yellow", bd =2, relief = tk.RIDGE)
self.parent = parent
self.controller = controller
self.pack(fill=tk.BOTH, expand=1)
for r in range(3):
self.rowconfigure(r, weight=1)
for c in range(4):
self.columnconfigure(c, weight=1)
self.frame=Small_Frame(self)
self.frame.grid(row = r, column = c, padx=1, pady = 1, sticky=
(tk.N, tk.S, tk.W, tk.E))
class Small_Frame(tk.Frame):
def __init__(self, parent):
tk.Frame.__init__(self, borderwidth=1, relief="groove")
self.parent = parent
self.pack(fill=tk.BOTH, expand=1)
class Controller():
def __init__(self):
self.root = tk.Tk()
self.view = View(self.root, self)
self.root.title("notbook my own try")
self.root.geometry("1200x650")
self.root.config(bg="LightBlue4")
self.root.mainloop()
if __name__ == "__main__":
c = Controller()

Answer 1

The problem is that you are mixing pack and grid with widgets that share a common parent.
First, you're creating a View object as a child of the root window, and you're calling pack to add it to the root window.
Next, you are creating a series of Small_Frame instances, but you are neglecting to pass the parent to the __init__ of the superclass so these instances become a child of the root window. The instance calls pack on itself, and then you call grid on the instance. Calling grid on the instance causes tkinter to get into an infinite loop as both grid and pack try to resize the parent in different ways. Each one triggers a redraw by the other one.
There are two things you need to do. First, remove self.pack(fill=tk.BOTH, expand=1) from the __init__ of Small_Frame. It's a bad practice to have a class call pack or grid on itself. The code that creates a widget should be responsible for adding it to the screen.
Second, you need to pass parent to __init__ method of the superclass in Small_Frame so that Small_Frame is a child of the correct parent. Your __init__ thus should look like this:
class Small_Frame(tk.Frame):
def __init__(self, parent):
tk.Frame.__init__(self, parent, borderwidth=1, relief="groove")
self.parent = parent