from Tkinter import *

if __name__ == "__main__":
    root = Tk()

    Button(root, text="Left").pack(side=LEFT, expand=YES, fill=Y)
    Button(root, text="Top").pack(side=TOP, expand=YES, fill=BOTH)
    Button(root, text="Right").pack(side=RIGHT, expand=YES, fill=X)

    root.mainloop()