Tkinter labels not filling up in the Y direction after using pack even though fill=tk.Y was added

I have been looking at various sources but to no avail.

In my tkinter window, I have running Labels which start with “start” to 1 and all the way to 100. I have two problems:

1. My labels are not stretching out in the Y direction even though fill=tk.Y is called (for self.firstlabel.pack and x.pack), as evidenced by the green background. Why is this happening?

2. I’ve also tried to get the canvas height by first calling self.update() and then printing out the canvas height using print(self.canvas.winfo_height()). However the canvas height is still 1. Why is this the case?

Thank you all in advance for your answers!

import tkinter as tk

class Test(tk.Tk):

    def __init__(self, tasks=None):
        super().__init__()

        self.title("Test")

        # setting up container
        container = tk.Frame(self, background="bisque")
        self.grid_rowconfigure(0, weight=1)
        self.grid_columnconfigure(0, weight=1)
        container.grid(row=0, column=0, sticky=(tk.N, tk.S, tk.E, tk.W))

        container.grid_columnconfigure(0, weight=1)
        container.grid_rowconfigure(0, weight=3)
        container.grid_rowconfigure(1, weight=1)

        # two frames in container, container1 for labels, container2 for textbox
        self.container1 = tk.Frame(container, background="yellow")
        self.container2 = tk.Frame(container, background="blue")
        self.container1.grid(row=0, sticky=(tk.N, tk.S, tk.E, tk.W))
        self.container2.grid(row=1, sticky=(tk.N, tk.S, tk.E, tk.W))

        self.canvas = tk.Canvas(self.container1, borderwidth=0, background="green")
        self.frameinsidecanvas = tk.Frame(self.canvas, background="pink")
        self.canvas.pack(fill="both", expand=True)
        self.frameinsidecanvas.pack(fill="both", expand=True)

        self.update()
        print(self.canvas.winfo_height())

        # setup scrollbar
        self.horizontalscrollbar = tk.Scrollbar(self.container1, orient="horizontal", command=self.canvas.xview)
        self.canvas.configure(xscrollcommand=self.horizontalscrollbar.set)
        self.horizontalscrollbar.pack(side="bottom", fill="x")

        self.canvas.create_window((0, 100), window=self.frameinsidecanvas, anchor="w")

        self.textbox = tk.Text(self.container2, height=1)
        self.textbox.pack(fill="both", expand=True)

        # creating the instructional label
        self.firstlabel = tk.Label(self.frameinsidecanvas, text="Start")
        # self.tasks.append(self.firstlabel)

        self.firstlabel.pack(side="left", fill=tk.Y, expand=True)

        # showing the labels
        for labels in range(0,100):
            x = tk.Label(self.frameinsidecanvas, text=str(labels))
            x.pack(side=tk.LEFT, fill=tk.Y, expand=True)

        self.bind("<Configure>", self.on_frame_configure)

    def on_frame_configure(self, event=None):
        self.canvas.configure(scrollregion=self.canvas.bbox("all"))

if __name__ == "__main__":
    test = Test()
    test.wm_geometry("1100x500")
    test.mainloop()