only one graph by matplotlib

anime.py

import pylab as p


p.ion()
x = p.arange(0, 2*p.pi, 0.01)
a = 10

curve = lambda t: (t, p.sin(x+t/10.0))

line, = p.plot(x, p.sin(x))
for t in p.arange(1,200):
    xs, ys = curve(t)
    line.set_ydata(ys)
    line.set_xdata(xs)
    p.draw()