delay image.destroy

Scripting Issues
2

Try this:

from direct.gui.OnscreenImage import OnscreenImage

class world:
  def __init__(self):
    imageObject = OnscreenImage(image = 'images/ridge_racer_menu.jpg', pos = (0, 0, 0))
    taskMgr.doMethodLater(5.0, image.destroy, 'destroyMyImage', extraArgs=[])

Hint: always import your modules at the top of your file, never inside a class or function definition.