any lib to convert 3200+ pic to animated gif?

[oyster]

I want to make an animated GIF from 3200+ png
I searched and found http://code.google.com/p/visvis/source/browse/#hg/vvmovie
and I wrote:
[code]
allPic=glob.glob('*.png')
allPic.sort()
allPic=[Image.open(i) for i in allPic]
writeGif('lala3.gif',allPic, duration=0.5, dither=0)
[/code]

However I got
[quote]
    allPic=[Image.open(i) for i in allPic]
  File "e:\prg\py\python-2.7.3\lib\site-packages\PIL\Image.py", line
1952, in open
    fp = __builtin__.open(fp, "rb")
IOError: [Errno 24] Too many open files: 'out0572.png'
[/quote]

Is there other lib for py? thanks