python 2.7 - Fish swim in pygame -

i want use python pygame module make 2d "fishtank".

basically load jpg image background , load gif animated image depicting fish swimming , make move.

i know how make static image move how make gif image move while image animated.

i have pil installed, sure if need use it.

if not work, can break apart gif file several static frames , cyclically make each of them show on screen. when latter 1 posted, former 1 needs removed, how remove ?

here class used in name pygame animation work:

class animation(pygame.sprite.sprite):     def __init__(self, img, fps = 6):         # call parent class (sprite) constructor          pygame.sprite.sprite.__init__(self)          # slice source image array of images         self.images = self.loadsliced(img)          # track time started, , time between updates.         # can figure out when have switch image.         self._start = pygame.time.get_ticks()         self._delay = 1000 / fps         self._last_update = 0         self._frame = 0         self.image = self._images[self._frame]  def loadsliced(w, h, filename):     """     pre-conditions:         master can height         sprites frames must same width         master width must len(frames)*frames.width      arguments:          w -- width of frame in pixels         h -- height of frame in pixels         filename -- master image animation     """     images = []      if fileexists( img, "animation master image"):         master_image = pygame.image.load(filename).convert_alpha()         master_width, master_height = master_image.get_size()         in range(int(master_width/w)):             images.append(master_image.subsurface((i*w, 0, w, h)))     return images  def update(self, t):     # note doesn't work if it's been more self._delay     # time between calls update(); update image once     # then. should updated twice      if t - self._last_update > self._delay:         self._frame += 1         if self._frame >= len(self._images):              self._frame = 0             self.image = self._images[self._frame]             self._last_update = t         self.image = self._images[self._frame]         self._last_update = t  def getframe(self, screen):     # update frame , display sprite     self.update(pygame.time.get_ticks())     return self.image