import tkinter as tk

window = tk.Tk()
button_1 = tk.Button(window, text="Regular button");
button_1["anchor"] = "e"
button_1["width"] = 20  # pixels!
button_1.pack()
button_2 = tk.Button(window, text="Another button")
button_2["anchor"] = "sw"
button_2["width"] = 20
button_2["height"] = 3  # rows
button_2.pack()
window.mainloop()