Arranging size of a frame in tkinter - python-3.x

Question

I am making a simple toolbox for my app. I have used the class method, which inherits Frame as its super class. In my main file I import this class.
It will be a main window which all widgets will be in it. But there is a problem, here is the source code:
from tkinter import *
class ToolBox(Frame):
def __init__(self, master=None,
width=100, height=300):
Frame.__init__(self, master,
width=100, height=300)
self.pack()
Button(self, text="B").grid(row=0, sticky=(N,E,W,S))
Button(self, text="B").grid(row=0, column=1, sticky=(N,E,W,S))
Button(self, text="B").grid(row=1, column=0,sticky=(N,E,W,S))
Button(self, text="B").grid(row=1, column=1, sticky=(N,E,W,S))
Button(self, text="B").grid(row=2, column=0, sticky=(N,E,W,S))
Button(self, text="B").grid(row=2, column=1, sticky=(N,E,W,S))
I import this in here:
from tkinter import *
import toolbox as tl
root = Tk()
frame = Frame(root, width=400, height=400)
frame.pack()
tl.ToolBox(frame).pack()
root.mainloop()
Main window, which is the root who has the frame, must be 400 in widht and height. But it appears in dimensions of my toolbox. I want the toolbox to be in the main window. How can I solve this?

Answer 1

You can force the root window to have specific dimensions using the geometry method.
root = Tk()
root.geometry("400x400")
If you would also like the buttons to stretch evenly to fill the whole root window, you need to do two things:
Call rowconfigure and columnconfigure to set the weight of the root and each frame that is a parent of your buttons.
specify the sticky parameter for every button and frame that is a child of your root.
Here's an example. I removed your frame Frame, since it didn't seem to be doing anything. Toolbox is already a frame, after all, and there's not much point putting a frame inside a frame.
from tkinter import *
class ToolBox(Frame):
def __init__(self, master=None,
width=100, height=300):
Frame.__init__(self, master,
width=width, height=height)
for i in range(2):
self.grid_columnconfigure(i, weight=1)
for j in range(3):
self.grid_rowconfigure(j, weight=1)
Button(self, text="B").grid(row=0, sticky=(N,E,W,S))
Button(self, text="B").grid(row=0, column=1, sticky=(N,E,W,S))
Button(self, text="B").grid(row=1, column=0,sticky=(N,E,W,S))
Button(self, text="B").grid(row=1, column=1, sticky=(N,E,W,S))
Button(self, text="B").grid(row=2, column=0, sticky=(N,E,W,S))
Button(self, text="B").grid(row=2, column=1, sticky=(N,E,W,S))
root = Tk()
root.geometry("400x400")
root.grid_rowconfigure(0, weight=1)
root.grid_columnconfigure(0, weight=1)
ToolBox(root).grid(sticky="news")
root.mainloop()
Now your root is properly sized, and your buttons stretch to fill it.