code: def clicked(self, px, py):
          '''see if the image has been clicked on'''
          if self.hidden:
              return None
          if (abs(px - self.posx) > self.width/2 or
              abs(py - self.posy) > self.height/2):
              return None
          return math.sqrt((px-self.posx)**2 + (py-self.posy)**2f clicked(self, px, py):
          '''see if the image has been clicked on'''
          if self.hidden:
              return None
          if (abs(px - self.posx) > self.width/2 or
              abs(py - self.posy) > self.height/2):
              return None
          return math.sqrt((px-self.posx)**2 + (py-self.posy)**2)
docs: see if the image has been clicked on