使用arcpy实现字段赋值

【解决办法】：
# -*- coding: UTF-8 -*-
import arcpy
arcpy.env.workspace = r''C:\Users\Administrator.ESRI-IT\Documents\ArcGIS\Default.gdb''
inFeatures = zz_80t_Identity
fieldName = A
expression =  !B!
arcpy.CalculateField_management(inFeatures, fieldName, expression, PYTHON_9.3)

print 0k