Actually, the code is not correct. The person who wrote it forgot to actually call the pack
method. You need to add ()
after it to do this:
from Tkinter import *
master=Tk()
w=Canvas(master, width=200, height=100)
########
w.pack()
########
w.create_line(0,0,200,100)
w.create_line(0,100,200,0, fill="red", dash=(4,4))
w.create_rectangle(50,25,150,75, fill="blue")
mainloop()
Otherwise, the canvas will never be placed on the window.
P.S. You should note that not everything you find on the Web is guaranteed to be correct. :)