TKinter Scrollbar - Problem with too many scrollbars - python-3.x

Question

I am building a simple UI using Tkinter and running into a problem when adding scrollbars. The layout of my UI (as shown below) consists of 5 frames, with one frame having 3 sub-frames. I am trying to add scrollbars to each frame and the sub-frames, however when I add the last scroll-bar to the sub-frame, all of the frames become smaller than their designated size. This only occurs when the final scrollbar is added.
Code:
import tkinter as tk
from tkinter import ttk
root = tk.Tk()
root.geometry("900x600")
notebook = ttk.Notebook(root)
frame1 = tk.Frame(root, width = 900, height = 600)
frame2 = tk.Frame(root, width = 900, height = 600)
frame3 = tk.Frame(root, width = 900, height = 600)
frame4 = tk.Frame(root, width = 900, height = 600)
frame5 = tk.Frame(root, width = 900, height = 600)
notebook.add(frame1, text = 'Frame 1')
notebook.add(frame2, text = 'Frame 2')
notebook.add(frame3, text = 'Frame 3')
notebook.add(frame4, text = 'Frame 4')
notebook.add(frame5, text = 'Frame 5')
canvas2 = tk.Canvas(frame2, width = 900, height = 600, scrollregion = (0, 0, 900, 600))
canvas3 = tk.Canvas(frame3, width = 900, height = 600, scrollregion = (0, 0, 900, 600))
canvas4 = tk.Canvas(frame4, width = 900, height = 600, scrollregion = (0, 0, 900, 600))
canvas5 = tk.Canvas(frame5, width = 900, height = 600, scrollregion = (0, 0, 900, 600))
canvas2.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
canvas3.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
canvas4.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
canvas5.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
et_vbar2 =tk.Scrollbar(canvas2, orient = tk.VERTICAL)
et_vbar2.pack(side = tk.RIGHT, fill = tk.Y)
et_vbar2.config(command=canvas2.yview)
canvas2.config(yscrollcommand = et_vbar2.set)
et_hbar2 =tk.Scrollbar(canvas2, orient = tk.HORIZONTAL)
et_hbar2.pack(side = tk.BOTTOM, fill = tk.X)
et_hbar2.config(command=canvas2.xview)
canvas2.config(xscrollcommand = et_hbar2.set)
et_vbar3 =tk.Scrollbar(canvas3, orient = tk.VERTICAL)
et_vbar3.pack(side = tk.RIGHT, fill = tk.Y)
et_vbar3.config(command=canvas3.yview)
canvas3.config(yscrollcommand = et_vbar3.set)
et_hbar3 =tk.Scrollbar(canvas3, orient = tk.HORIZONTAL)
et_hbar3.pack(side = tk.BOTTOM, fill = tk.X)
et_hbar3.config(command=canvas3.xview)
canvas3.config(xscrollcommand = et_hbar3.set)
et_vbar4 =tk.Scrollbar(canvas4, orient = tk.VERTICAL)
et_vbar4.pack(side = tk.RIGHT, fill = tk.Y)
et_vbar4.config(command=canvas4.yview)
canvas4.config(yscrollcommand = et_vbar4.set)
et_hbar4 =tk.Scrollbar(canvas4, orient = tk.HORIZONTAL)
et_hbar4.pack(side = tk.BOTTOM, fill = tk.X)
et_hbar4.config(command=canvas4.xview)
canvas4.config(xscrollcommand = et_hbar4.set)
et_vbar5 =tk.Scrollbar(canvas5, orient = tk.VERTICAL)
et_vbar5.pack(side = tk.RIGHT, fill = tk.Y)
et_vbar5.config(command=canvas5.yview)
canvas5.config(yscrollcommand = et_vbar5.set)
et_hbar5 =tk.Scrollbar(canvas5, orient = tk.HORIZONTAL)
et_hbar5.pack(side = tk.BOTTOM, fill = tk.X)
et_hbar5.config(command=canvas5.xview)
canvas5.config(xscrollcommand = et_hbar5.set)
notebook.pack()
notebook2 = ttk.Notebook(frame1)
tab1 = tk.Frame(frame1, width = 900, height = 600)
tab2 = tk.Frame(frame1, width = 900, height = 600)
tab3 = tk.Frame(frame1, width = 900, height = 600)
notebook2.add(tab1, text= 'Tab 1')
notebook2.add(tab2, text = 'Tab 2')
notebook2.add(tab3, text = 'Tab 3')
subcanvas1 = tk.Canvas(tab1, width = 900, height = 600, scrollregion = (0, 0, 900, 600))
subcanvas2 = tk.Canvas(tab2, width = 900, height = 600, scrollregion = (0, 0, 900, 600))
subcanvas3 = tk.Canvas(tab3, width = 900, height = 600, scrollregion = (0, 0, 900, 600))
subcanvas1.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
subcanvas2.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
subcanvas3.pack(side = tk.LEFT, fill = tk.BOTH, expand = 1)
subet_vbar1 =tk.Scrollbar(subcanvas1, orient = tk.VERTICAL)
subet_vbar1.pack(side = tk.RIGHT, fill = tk.Y)
subet_vbar1.config(command=subcanvas1.yview)
subcanvas1.config(yscrollcommand = subet_vbar1.set)
subet_hbar1 =tk.Scrollbar(subcanvas1, orient = tk.HORIZONTAL)
subet_hbar1.pack(side = tk.BOTTOM, fill = tk.X)
subet_hbar1.config(command=subcanvas1.xview)
subcanvas1.config(xscrollcommand = subet_hbar1.set)
subet_vbar2 =tk.Scrollbar(subcanvas2, orient = tk.VERTICAL)
subet_vbar2.pack(side = tk.RIGHT, fill = tk.Y)
subet_vbar2.config(command=subcanvas2.yview)
subcanvas2.config(yscrollcommand = subet_vbar2.set)
subet_hbar2 =tk.Scrollbar(subcanvas2, orient = tk.HORIZONTAL)
subet_hbar2.pack(side = tk.BOTTOM, fill = tk.X)
subet_hbar2.config(command=subcanvas2.xview)
subcanvas2.config(xscrollcommand = subet_hbar2.set)
subet_vbar3 =tk.Scrollbar(subcanvas3, orient = tk.VERTICAL)
subet_vbar3.pack(side = tk.RIGHT, fill = tk.Y)
subet_vbar3.config(command=subcanvas3.yview)
subcanvas3.config(yscrollcommand = subet_vbar3.set)
subet_hbar3 =tk.Scrollbar(subcanvas3, orient = tk.HORIZONTAL)
subet_hbar3.pack(side = tk.BOTTOM, fill = tk.X)
subet_hbar3.config(command=subcanvas3.xview)
subcanvas3.config(xscrollcommand = subet_hbar3.set)
notebook2.pack()
root.mainloop()
Is there a way to prevent every frame from becoming smaller after adding the scrollbars?

Answer 1

There's a number of problems in your code. Rather than try to fix them, I think you should cheat and use the code from someone who has abstracted this. There are many people who have made a scrolledframe in some form, including me. To use mine, download the DoubleScrolledFrame.py file from here and then:
import tkinter as tk
from tkinter import ttk
from DoubleScrolledFrame import DoubleScrolledFrame
def add_scrolled_frame(notebook, text):
"""do this in a function so that you can easily change parameters"""
frame = DoubleScrolledFrame(notebook, width = 900, height = 600)
notebook.add(frame, text = text)
return frame
root = tk.Tk()
notebook = ttk.Notebook(root)
frame1 = tk.Frame(root)
notebook.add(frame1, text = 'Frame 1')
frame2 = add_scrolled_frame(notebook, text = 'Frame 2')
frame3 = add_scrolled_frame(notebook, text = 'Frame 3')
frame4 = add_scrolled_frame(notebook, text = 'Frame 4')
frame5 = add_scrolled_frame(notebook, text = 'Frame 5')
notebook.pack()
notebook2 = ttk.Notebook(frame1)
tab1 = add_scrolled_frame(notebook2, text = 'Tab 1')
tab2 = add_scrolled_frame(notebook2, text = 'Tab 2')
tab3 = add_scrolled_frame(notebook2, text = 'Tab 3')
notebook2.pack()
# assuming you want widgets in these frames:
for i in range(30):
lbl = tk.Label(tab1, text=f'This is label number {i}')
lbl.pack()
root.mainloop()