arcgis python 列举所有栅格ListRasters

import arcgisscripting
gp = arcgisscripting.create()

gp.workspace = "c:/DEMs"

# Get a list of grids in the workspace.
rasters = gp.ListRasters("", "GRID")

raster = rasters.next()
while raster:
    print raster
    raster = rasters.next()