How To Change Image In Canvas?[python Tkinter]

As below, I want to show an image in canvas using tkinter, and when a click the button, an other photo should be shown. But I failed. The first image shows well, but the image didn

Solution 1:

Changes one or more options for all matching items. 1

myimg = C.create_image(300, 250, image=itk)

def changeImage():
    // I want to show image2 in canvas, but I fails
    print 'change image in canvas'
    itk2 = ImageTk.PhotoImage(img2)
    C.itemconfigure(myimg, image=itk2)