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.management.AddField(inFeatures, newField, "TEXT")
arcpy.management.MakeFeatureLayer(inFeatures, layerName)
arcpy.management.AddJoin(layerName, joinField, joinTable, joinField)
arcpy.management.CalculateField(layerName, newField, calcExpression, "PYTHON")
arcpy.management.RemoveJoin(layerName, "vegtable")
arcpy.management.CopyFeatures(layerName, outFeature)