How can I append in item to a list from a class?

Question

I was programming a little game in pygame and I had to add items to a list from a class, but when I run the code the second "obstacle" doesn't appear because the function "move" in the "obstacle" class does not append the item to the list. Does someone know how to fix that?

Here is some code:

obs = []

class obstacles():
    def __init__(self):
        self.x = screen_width
        self.y = screen_height - ob_height
        self.rect = Rect(self.x, self.y, ob_width, ob_height)
        self.speed = 4
    

    def draw(self):
        pygame.draw.rect(screen, ob_col, self.rect)
    

    def move(self):
        self.rect.x -= self.speed
        if self.rect.x < 100:
            obs.append(obstacles())
    

def init():
   obs.append(obstacles())

  
ob_disegno = obstacles()
sq_disegno = square()

init()

run = True

while run:
    
        clock.tick(fps)
        screen.fill(background)

        ob_disegno.move()
        sq_disegno.draw()
    
        for i in obs:
            ob_disegno.draw()

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                 run = False


        pygame.display.update()


pygame.quit()

Answer 1

Of course, the object is added to the list. However, you never draw the objects in the list, so you never see the new objects. You just draw ob_disegno :

 for i in obs: ob_disegno.draw()

You need to move and draw the elements of the list:

for ob in obs:
    ob.move()
    ob.draw()