python - How to update an image on a Canvas?

Question

This is the essence of the code I'm having trouble with:

camelot = Canvas(main, width = 400, height = 300)
camelot.grid(row = 0, column = 0, rowspan = 11, columnspan = 3)
MyImage = PhotoImage(file = "sample1.gif")
camelot.create_image(0, 0, anchor = NW, image = MyImage)

This is run at the beginning. What I want to do on later in another function is replace "sample1.gif" by "sample2.gif", and, possibly later on, replace that in turn by "sample3.gif". I'm stuck and nothing I've been trying has worked so far.

Answer 1

Add image to canvas:

self.image_on_canvas = self.canvas.create_image(0, 0, image = ...)

Change image:

self.canvas.itemconfig(self.image_on_canvas, image = ...)

---

Full example:

from Tkinter import *

#----------------------------------------------------------------------

class MainWindow():

    #----------------

    def __init__(self, main):

        # canvas for image
        self.canvas = Canvas(main, width=60, height=60)
        self.canvas.grid(row=0, column=0)

        # images
        self.my_images = []
        self.my_images.append(PhotoImage(file = "ball1.gif"))
        self.my_images.append(PhotoImage(file = "ball2.gif"))
        self.my_images.append(PhotoImage(file = "ball3.gif"))
        self.my_image_number = 0

        # set first image on canvas
        self.image_on_canvas = self.canvas.create_image(0, 0, anchor = NW, image = self.my_images[self.my_image_number])

        # button to change image
        self.button = Button(main, text="Change", command=self.onButton)
        self.button.grid(row=1, column=0)

    #----------------

    def onButton(self):

        # next image
        self.my_image_number += 1

        # return to first image
        if self.my_image_number == len(self.my_images):
            self.my_image_number = 0

        # change image
        self.canvas.itemconfig(self.image_on_canvas, image = self.my_images[self.my_image_number])

#----------------------------------------------------------------------

root = Tk()
MainWindow(root)
root.mainloop()

Images used in example:

ball1.gif ball2.gif ball3.gif

Result: