from tkinter import *

win  = Tk()

b = Button(win, text="Top")
b.pack(side=TOP)


b2 = Button(win, text="Right")
b2.pack(side=RIGHT)


b3 = Button(win, text="Left")
b3.pack(side=LEFT, fill=BOTH,expand=True)

b4 = Button(win, text="Bottom")
b4.pack(side=BOTTOM)


win.mainloop()