from pylab import *

marqueurs = ['o', '+', '.', 'x', '*', '^']

x = [-1, 0, 1, 2]
y = [3, 2, 4, 1]

for m in marqueurs:
    i = marqueurs.index(m) + 1
    subplot(2, 3, i, axisbg='0.8')     # nuance de gris
    xticks([])
    yticks([])
    plot(x, y, 'g'+m)
    axis([-2,3,0,5])

show()