from tkinter import *
root = Tk()
c = Canvas(width=200, height=200, bg='green')
c.pack()
rect = c.create_rectangle(80, 80, 120, 120, fill='yellow')
def inFocus(event):
    c.itemconfig(rect, fill='red', width=2)
    c.coords(rect, 70, 70, 130, 130)
c.bind('<FocusIn>', inFocus)
root.mainloop()