Drag and drop sprite without "cloning" in Pygame?

Question

Python

I want to drag the image from one position to another without having to clear the back surface every pass in the loop thanks to screen.fill(BLACK), since the background is not a solid color

while run:
    for event in pygame.event.get():
        pos = pygame.mouse.get_pos()
        if event.type == pygame.QUIT:
            run = False
        if event.type == pygame.MOUSEBUTTONDOWN:
            if event.button == 1:
                run = False
        if event.type == pygame.MOUSEMOTION:
               #screen.fill(BLACK)
        screen.blit(img, [pos[0], pos[1]])
    pygame.display.flip()
pygame.quit()