arcgis python 获得消息的个数

import arcgisscripting
gp = arcgisscripting.create()

gp.workspace = "H:/Forestry"
gp.toolbox = "analysis"

gp.clip("final_forest/polygon", "clipcov/polygon", "output.shp", "1.25")

y = gp.messagecount
x = 0
while x < y:
    print gp.getmessage(x)
    x = x + 1