pack

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# posicionamiento pack

import tkinter as tk
from tkinter import ttk

ventana = tk.Tk()
ventana.title("Posicionamiento PACK")
ventana.config(width=400, height=800)

caja1 = ttk.Entry()
caja1.pack()

boton = ttk.Button(text="Hola mundo")
boton.pack()

label = ttk.Label(text="....desde TKinter")
label.pack()

caja = ttk.Entry()
caja.pack(side=tk.BOTTOM)

label = ttk.Label(text="HOLLLAAAAA...")
label.pack(before=caja1)

boton2 = ttk.Button(text="Mundo cruel")
boton2.pack(after=caja, padx=30, pady=30, ipadx=100, ipady=5)

caja2 = ttk.Entry()
caja2.pack(side=tk.RIGHT, expand=True, fill=tk.BOTH)

ventana.mainloop()