How to show up some graphs one by one automatically

Hi,
I want to write a program that will show up some graphs one by one
automatically, but it turns out that I have to close the very first one
manually (which is not what I want), then the following will show up
automatically one by one. Any suggestions will be greatly appreciated.
Best Regards, John

from pylab import *

a=[1,2,3,4,5]
b=[1,2,3,4,5]
c=[2,4,9,16,25]

clf()
plot(a,b)
show()
close()

plot(a,c,'r')
show()
close()

plot(a,c,'r')
show()
close()

http://matplotlib.sourceforge.net/faq.html#SHOW

hth,
Alan Isaac