python tkinter image layers (paste / unpaste image on background) - python-3.x

Question

i have a background image using tkinter canvas,
and i'm adding images on top of it.
so far so good it works well. but what i would like to do is to be able to remove some of the forground images on demand. and when i remove some of them i would like to see the background behind them as it were before adding those forground images on it.
that would be like: paste 5 foreground images and then remove 1 or 2 of them.
so this program i have to far, adds little white filled circles at random position.
if i keep a handle on every little white circles (i can put them in variables and have them all in a list, and get their coordinates later for example). how can i remove some of them and get to see my background behind the removed whites circles ?
is it even possible ?
#!/usr/bin/env python3
from tkinter import *
from PIL import Image, ImageTk
from random import *
class App(object):
def __init__(self):
self.root = Tk()
self.canvas = Canvas(self.root, height=222, width=227)
self.canvas.grid()
# small nature landscape
self.backgnd = PhotoImage( file = "images/nature.png" )
# small white circle
self.mycloud = PhotoImage( file = "images/white.png" )
backgnd_width = (self.backgnd.width()/2)
backgnd_height = (self.backgnd.height()/2)
self.canvas.create_image(backgnd_width,backgnd_height,image=self.backgnd)
def cloud(self):
pos_x = randint(1,220)
pos_y = randint(1,220)
self.canvas.create_image(pos_x,pos_y, image=self.mycloud)
app = App()
app.cloud()
app.cloud()
app.cloud()
app.cloud()
app.cloud()
app.root.mainloop()

Answer 1

in case it might help others here's a working solution.
i added a button that will remove each object placed on the canvas, one a a time.
(thanks for the help, Bryan Oakley)
#!/usr/bin/env python3
from tkinter import *
from PIL import Image, ImageTk
from tkinter import ttk
from random import *
class App(object):
def __init__(self):
self.root = Tk()
self.canvas = Canvas(self.root, height=300, width=227)
self.canvas.grid()
self.mylist=[]
self.backgnd = PhotoImage( file = "images/nature.png" )
self.mycloud = PhotoImage( file = "images/white.png" )
backgnd_width = (self.backgnd.width()/2)
backgnd_height = (self.backgnd.height()/2)
self.canvas.create_image(backgnd_width,backgnd_height,image=self.backgnd)
# button to remove things on the canvas
button_del = ttk.Button(self.root, text='Del')
button_del['command'] = self.rem
button_del.place(x=100, y=250)
def cloud(self):
# add 5 object at random position on the canvas
for idx in range(5):
pos_x = randint(1,220)
pos_y = randint(1,220)
self.mylist.append(self.canvas.create_image(pos_x,pos_y, image=self.mycloud))
def rem(self):
# delete elements placed on the canvas
self.canvas.delete(self.mylist[-1])
self.mylist.pop()
app = App()
app.cloud()
app.root.mainloop()

Answer 2

made a few changes to make above code compatible with python 2:
from Tkinter import *
from PIL import Image, ImageTk
import ttk
from random import *
class App(object):
def __init__(self):
self.root = Tk()
self.canvas = Canvas(self.root, height=300, width=227)
self.canvas.grid()
self.mylist=[]
self.backgnd = ImageTk.PhotoImage( Image.open("sunshine.jpg") )
self.mycloud = ImageTk.PhotoImage( Image.open("Y.png") )
backgnd_width = (self.backgnd.width()/2)
backgnd_height = (self.backgnd.height()/2)
self.canvas.create_image(backgnd_width,backgnd_height,image=self.backgnd)
# button to remove things on the canvas
button_del = ttk.Button(self.root, text='Del')
button_del['command'] = self.rem
button_del.place(x=100, y=250)
def cloud(self):
# add 5 object at random position on the canvas
for idx in range(5):
pos_x = randint(1,220)
pos_y = randint(1,220)
self.mylist.append(self.canvas.create_image(pos_x,pos_y, image=self.mycloud))
def rem(self):
# delete elements placed on the canvas
self.canvas.delete(self.mylist[-1])
self.mylist.pop()
app = App()
app.cloud()
app.root.mainloop()