from tkinter import *
def new_size(canvas, size, my_object):
canvas.itemconfig(my_object, 10, 10, 90, 90)
if __name__ == '__main__':
root = Tk()
canvas = Canvas(root, width=500, height=500)
canvas.grid()
red = canvas.create_rectangle(20, 20, 100, 100)
new_size(canvas, 0, red)