Fish swim in pygame - python-2.7

Question

I want to use the python pygame module to make a 2D "fishtank".
Basically I will load a jpg image as background and load a gif animated image depicting fish swimming and make it move.
I know how to make an static image move but how to make a gif image move while the image itself is animated.
I have PIL installed, do sure if need to use it.
If that does not work, I can also break apart the gif file into several static frames and cyclically make each of them show on screen. When the latter one is posted, the former one needs to be removed, how to remove it ?

Answer 1

Here is a class I used in my name to get PyGame animation to work:
class Animation(pygame.sprite.Sprite):
def __init__(self, img, fps = 6):
# Call the parent class (Sprite) constructor
pygame.sprite.Sprite.__init__(self)
# Slice source image to array of images
self.images = self.loadSliced(img)
# Track the time we started, and the time between updates.
# Then we can figure out when we have to switch the 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 be any height
Sprites frames must be the same width
Master width must be len(frames)*frames.width
Arguments:
w -- Width of a frame in pixels
h -- Height of a frame in pixels
filename -- Master image for animation
"""
images = []
if fileExists( img, "Animation Master Image"):
master_image = pygame.image.load(filename).convert_alpha()
master_width, master_height = master_image.get_size()
for i in range(int(master_width/w)):
images.append(master_image.subsurface((i*w, 0, w, h)))
return images
def update(self, t):
# Note that this doesn't work if it's been more than self._delay
# time between calls to update(); we only update the image once
# then. but it really should be 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 and Display Sprite
self.update(pygame.time.get_ticks())
return self.image