import arcpy
arcpy.env.workspace = "C:/data"
arcpy.env.qualifiedFieldNames = "UNQUALIFIED"
inFeatures = "Habitat_Analysis.gdb/vegtype"
layerName = "veg_layer"
newField = "description"
joinTable = "vegtable.dbf"
joinField = "HOLLAND95"
calcExpression = "!vegtable.VEG_TYPE!"
outFeature = "Habitat_Analysis.gdb/vegjoin335"
arcpy.AddField_management (inFeatures, newField, "TEXT")
arcpy.MakeFeatureLayer_management (inFeatures, layerName)
arcpy.AddJoin_management (layerName, joinField, joinTable, joinField)
arcpy.CalculateField_management (layerName, newField, calcExpression, "PYTHON")
arcpy.RemoveJoin_management (layerName, "vegtable")
arcpy.CopyFeatures_management (layerName, outFeature)