how to draw loop auto line in python using tkinter

# using the Tkinter canvas to# draw a line from coordinates x1,y1 to x2,y2# create_line(x1, y1, x2, y2, width=1, fill="black")try:    # Python2    import Tkinter as tkexcept ImportError:    # Python3    import tkinter as tkroot = tk.Tk()root.title("drawing lines")# create the drawing canvascanvas = tk.Canvas(root, width=450, height=450, bg='white')canvas.pack()# draw horizontal linesx1 = 0x2 = 450for k in range(0, 500, 50):    y1 = k    y2 = k    canvas.create_line(x1, y1, x2, y2)# draw vertical linesy1 = 0y2 = 450for k in range(0, 500, 50):    x1 = k    x2 = k    canvas.create_line(x1, y1, x2, y2)root.mainloop()