Button changes frame size in Tkinter

Question

I'm new to Tkinter, and have a problem with my frames when adding widgets. In this example, I add a button which makes my frame wider when I place the button inside it with .grid().

How can I make the frame "fixed"? I want the blue frame in the code below to keep the same width when I add the button.

Thanks in advance.

Regards, Laphroaig

class Window(Frame):

    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.master = master
        master.title("Yatzy - The Game")
        master.geometry("800x600+0+0")
        master.iconbitmap(r'dice.ico')
        master.state('zoomed')

        # Create grid index for the window
        for r in range(20):
            self.master.rowconfigure(r, weight=1)

        for c in range(20):
            self.master.columnconfigure(c, weight=1)


        # Place Frame 1
        Frame1 = Frame(master, bg="blue")
        Frame1.grid(row = 0, column = 0, rowspan = 20, columnspan = 3, sticky=W+E+N+S)

        # Place Frame 2
        Frame2 = Frame(master, bg="green")
        Frame2.grid(row=0, column=3, rowspan=20, columnspan=17, sticky = W+E+N+S)

        # Place Frame 3
        Frame3 = Frame(master, bg="red")
        Frame3.grid(row=5, column=8, rowspan=10, columnspan=7, sticky = W+E+N+S)

        # Place button 1
        btn_1 = Button(master, text="hello123")
        btn_1.grid(row=0, column=0)


root = Tk()
app = Window(master=root)
app.mainloop()

Answer 1

You can stop content from affecting the size of a Frame with grid_propagate(False). See example below.

Other things; You inherit from Frame but never put anything inside self, instead you put everything inside self.master ie. root. I changed to put everything in self and then pack self within root.

I also removed the icon as I don't have your icon file.

from tkinter import *

class Window(Frame):

    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.master = master
        master.title("Yatzy - The Game")
        master.geometry("800x600+0+0")
        master.state('zoomed')
        self.pack(expand=True, fill='both')

        # Create grid index for the window
        for r in range(20):
            self.rowconfigure(r, weight=1)

        for c in range(20):
            self.columnconfigure(c, weight=1)


        # Place Frame 1
        Frame1 = Frame(self, bg="blue")
        Frame1.grid(row = 0, column = 0, rowspan = 20, columnspan = 3, sticky=W+E+N+S)
        Frame1.grid_propagate(False) # Stop grid() from resizing container

        # Place Frame 2
        Frame2 = Frame(self, bg="green")
        Frame2.grid(row=0, column=3, rowspan=20, columnspan=17, sticky = W+E+N+S)

        # Place Frame 3
        Frame3 = Frame(self, bg="red")
        Frame3.grid(row=5, column=8, rowspan=10, columnspan=7, sticky = W+E+N+S)

        # Place button 1
        btn_1 = Button(Frame1, text="hello123")
        btn_1.grid(row=0, column=0)


root = Tk()
app = Window(master=root)
app.mainloop()