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Tkinter scrollbar is not scrolling

As part of a tkinter app I'm building using Python 3.8, I need a particular tab in a Notebook to be scrollable. The notebook needs to remain at a fixed size, but the problem is that there will be cases in which the contents of the tab will exceed the size of the notebook.
The scrollbar appears as it should, but scrolling appears to have no effect on the contents of the tab. It looks like it thinks it's scrolling something but I do not know what. Here's an isolated example of a tab with a scrollbar which has no effect:
import tkinter as tk
from tkinter import ttk
root = tk.Tk()
tabs = ttk.Notebook(root, width=200, height=650)
tab_options = tk.Frame(tabs)
tabs.add(tab_options, text="Options")
main_frame = tk.Frame(tab_options)
main_frame.pack()
canvas = tk.Canvas(main_frame)
canvas.pack(side="left",fill="both",expand=1)
scrollbar = ttk.Scrollbar(main_frame,orient="vertical",command=canvas.yview)
scrollbar.pack(side="right", fill="y",expand=1)
lf_options = tk.Frame(canvas)
lf_options.pack()
canvas.configure(yscrollcommand=scrollbar.set)
canvas.configure(scrollregion=(0,0,200,1000))
for i in range(50):
ttk.Label(lf_options, text=str(i)).pack()
tabs.pack()
root.mainloop()
I imagine it's something to do with how I'm hooking up the frames to the canvas but I cannot for the life of me get it to work. I've seen suggestions about setting scrollregion to
canvas.bbox("all")
but I don't understand how to associate that with the maximum height that can be displayed, i.e. the height of the notebook itself. Using that as the scrollregion also just makes the scrollbar unscrollable.
I know there are many similar questions on here, but I have not found any of those examples to work in this case.
Any advice would be greatly appreciated. Thanks!

It seems more logical to use a tk.Listbox for this purpose, see below for example an edited version of your code. Here the scrollbar works just as expected!
import tkinter as tk
from tkinter import ttk
root = tk.Tk()
tabs = ttk.Notebook(root, width=200, height=650)
tab_options = tk.Frame(tabs)
tabs.add(tab_options, text="Options")
listbox = tk.Listbox(tab_options)
for i in range(50):
listbox.insert(tk.END, f"Number {i}")
listbox.pack(side="left", fill="both", expand=1)
scrollbar = ttk.Scrollbar(tab_options, orient="vertical", command=listbox.yview)
scrollbar.pack(side="right", fill="y", expand=1)
listbox.configure(yscrollcommand=scrollbar.set)
tabs.pack()
root.mainloop()

How do I change the size of a tkinter canvas through a new window?

So I have one Tkinter screen that has a canvas. I want to change the size of the canvas by creating a new window that has entry widgets. So I created a new screen and added 2 entry widgets. I want to get the value from those widgets and based on that...it should change the size of the canvas. I tried to do this for an hour, but no luck. Please assist me.
Here is my code
from tkinter import *
# create root window
root = Tk()
# Create Canvas
canvas = Canvas(root, width=50, height=50)
# Create an additional window (the one that is used to enter the new geometry)
dialog = Toplevel(root)
# Add entry widgets for width and height to the new window
width_entry = tk.Entry(dialog)
height_entry = tk.Entry(dialog)
# Add a button to the new window that applies the given width and height
apply_button = Button(dialog, text = 'Apply geometry', command = lambda: canvas.geometry(width_entry.get()+'x'+height_entry.get()))
# Its not possible to get the geometry of a canvas in tkinter...so how do I change the size.
# display the entry boxes and button
width_entry.pack()
height_entry.pack()
apply_button.pack()
# start the tk mainloop
root.mainloop()
Please Assist me

The command you are looking for is canvas.config
Here, I have adjusted the given code:
import tkinter as tk
# create root window
root = tk.Tk()
# Create Canvas
canvas = tk.Canvas(root, width=50, height=50)
canvas.pack()
# Create an additional window (the one that is used to enter the new geometry)
dialog = tk.Toplevel(root)
# Add entry widgets for width and height to the new window
width_entry = tk.Entry(dialog)
height_entry = tk.Entry(dialog)
# Add a button to the new window that applies the given width and height
apply_button = tk.Button(dialog, text = 'Apply geometry', command = lambda: canvas.config(width=width_entry.get(), height=height_entry.get()))
# display the entry boxes and button
width_entry.pack()
height_entry.pack()
apply_button.pack()
# start the tk mainloop
root.mainloop()
I also changed a couple other things:
You imported * from tkinter, but for some items you still led with tk.; I changed them all to match that and switched the import to match as well. (You could still use *, but then just don't have the leading tk.s.)
The canvas was never packed so you could never see what was going on there.
One more suggestion, that line where you make the button is really long. Maybe make a function that does what the lambda does and assign its command to that function instead of a lambda. You can probably see that a line that long is even hard to read here much less if someone (maybe a future version of yourself) was to try to read your code, and edit it or make sense of it. Generally, try to keep all lines down to 80 characters.
Let us know if you have any more questions etc.

How to access entries beyond the window size in Tkinter

I am creating a form with 40 labels and entries. The problem is that I can enter till 20 after that the window size reaches the maximum and I cannot see entries below it. How do I integrate a scrolling option in Tkinter main window? I know that scrollbar cannot be integrated into main window and only to widgets. I want something so that I can either scroll using mouse or arrow keys or anything to see below content. Below is my code:
from Tkinter import *
root = Tk()
root.title('test')
root.geometry("400x400")
for i in range(40):
Label(root, text="Field {} ".format(i)).grid(row=i,column=0)
value=Entry(root).grid(row=i,column=1)
root.mainloop()
Output image

ListBox
Scrollbars are almost always used in conjunction with Listbox, Canvas or Text widget. To connect a vertical scrollbar to one of these widgets you have to do two things:
Set the widget’s yscrollcommand callbacks to the set method of the scrollbar.
Set the scrollbar’s command to the yview method of the widget.
Example
from tkinter import *
master = Tk()
scrollbar = Scrollbar(master)
scrollbar.pack(side=RIGHT, fill=Y)
listbox = Listbox(master, yscrollcommand=scrollbar.set)
for i in range(40):
listbox.insert(END, Label(master, text=f"Field {i} "))
listbox.insert(END, Entry(master))
listbox.pack(side=LEFT, fill=BOTH)
scrollbar.config(command=listbox.yview)
mainloop()

Python tkinter label image not drawn unless a message widget is behind it

I have a transparent tkinter message widget and a label, one containing text the other an image, the image is only drawn in the parts where the text label is behind it. 1
I'm using python tkinter on windows 7 to draw the labels on the desktop on a transparent window, so what you're seeing in the background is my regular windows desktop, which might have something to do with it
Here are snippets of code, but there is alot more that's not relevant I think
x = Tk()
label = tkinter.Message(x, textvariable=text, font=('Terminal','10'), fg='white', bg='green', width=800, anchor='n')
label.master.overrideredirect(True)
label.master.geometry('+30+30')
label.master.lift()
label.master.wm_attributes('-transparentcolor', 'green')
label.pack()
Then this is inside a function which is called to display the plot
new_plot = Label(x, image=plot_image, fg='white', bg='green', anchor='n', width=640, height=480)
new_plot.image = plot_image
new_plot.master.wm_attributes('-transparentcolor', 'green')
new_plot.place(x = 20, y = 30, width=640, height=480)
new_plot.update()
Then at the end
x.mainloop()
I hope this is all that's relevant to the problem

I suspect it has to do with the fact that a tkinter window by default is 1x1 pixel in size. When you use place, tkinter will not expand the window to fit its contents.
The reason it works with the messagebox is because you are adding the messagebox to the root window with pack which will cause the window to grow.
The simple solution is to use new_plot.pack(...) instead of new_plot.place(...).

Tkinter : How to center the window title

I am creating a project using tkinter and when I create a window, I couldn't seem to get the window title to center itself (Like most programs nowadays). Here's the example code:
from tkinter import *
root = Tk()
root.title("Window Title".center(110))# Doesn't seem to work
root.mainloop()
Is there a way to center the window title up ? Thanks in advance

There is nothing you can do. Tkinter has no control over how the window manager or OS displays the titles of windows other than to specify the text.

I came up with a trick that does the job and it consists in simply adding as much blank space before the title:
import tkinter as tk
root = tk.Tk()
root.title(" Window Title")# Add the blank space
frame = tk.Frame(root, width=800, height=200, bg='yellow')
frame.grid(row=0,column=0)
root.mainloop()
Output:
Alternatively, you can use a string consisting of an empty space and concatenate it to the title after multiplication. I mean:
import tkinter as tk
root = tk.Tk()
blank_space =" " # One empty space
root.title(80*blank_space+"Window Title")# Easier to add the blank space
frame = tk.Frame(root, width=800, height=200, bg='yellow')
frame.grid(row=0,column=0)
root.mainloop()

More adding onto what Billal suggested is this example that adjust depending on the window size. I still wouldn't recommend it since it's just a hack for visual aesthetics but if you really want to have it.
import tkinter as tk
def center(e):
w = int(root.winfo_width() / 3.5) # get root width and scale it ( in pixels )
s = 'Hello Word'.rjust(w//2)
root.title(s)
root = tk.Tk()
root.bind("<Configure>", center) # called when window resized
root.mainloop()

width=root.winfo_screenwidth()
spacer=(" "*(int(width)//6))
root.title(spacer+"Your title")
This is not that much perfect but this will work.