from Tkinter import *
class monAppli(Frame):
    def __init__(self,boss=None,larg=100,haut=150):
        Frame.__init__(self)
        self.configure(width=larg,height=haut)
        self.can=Canvas(self,width=larg,height=haut,bg='ivory')
        self.can.pack(side=TOP)
        self.cercle=self.can.create_oval(50,50,150,150,fill="black" )
        Scale(self,orient=HORIZONTAL,width=20,label="taille",from_=10.,to=200.,showvalue=1,command=self.retaille).pack()
                 
    def retaille(self,size):
        self.can.delete(self.cercle)
        self.cercle=self.can.create_oval(50,50,50+int(size),50+int(size),fill="black" )
               
##code test###
if  __name__=="__main__":
    root=Tk()
    monAppli(root,300,300).pack()
    root.mainloop()