python 獲得一個數據的坐標系

# ---------------------------------------------------------------------------
# 1.py  閆磊編寫
# Created on: 2011-05-06 16:56:36.00000
#   (generated by ArcGIS/ModelBuilder)
# Description: 
# ---------------------------------------------------------------------------

import arcpy

featureClass = arcpy.GetParameterAsText(0) #"F:\閆磊\data\Chinadata\shp\主要公路.shp"
desc = arcpy.Describe(featureClass)

# Print selected feature class properties
# 
print "shapeType", desc.shapeType
print "hasSpatialIndex", desc.hasSpatialIndex
print "extent XMin", desc.extent.XMin
print "extent YMax", desc.extent.YMax
print "the first field's name", desc.fields[0].name
print "the first field's type", desc.fields[0].type
print "坐標", desc.spatialReference


# Obtain the spatial reference object and return it to the tool.
SR = desc.spatialReference
arcpy.SetParameter(1, SR)
arcpy.AddMessage(" spatialReference " + str(SR))