# Tk_frame_size.py

# Tk_frame_size.py

from Tkinter import *

def small(event):
    fra.configure(width=300)
def middle(event):
    fra.configure(width=600)
def big(event):
    fra.configure(width=900)

root = Tk()

fra = Frame(root,width=300,height=100,bg="green")
but1 = Button(root,text="300x100")
but2 = Button(root,text="600x100")
but3 = Button(root,text="900x100")

but1.bind("<Button-1>",small)
but2.bind("<Button-1>",middle)
but3.bind("<Button-1>",big)

fra.grid(row=0,column=0,columnspan=3)
but1.grid(row=1,column=0)
but2.grid(row=1,column=1)
but3.grid(row=1,column=2)

root.mainloop()