dynamo_list-loaded-builtincategories.py

#this script lists the BuiltInCategories currently loaded in a Revit document
#can be easily tweaked to instead list categories only

import clr
clr.AddReference('RevitAPI')
from Autodesk.Revit.DB import *

clr.AddReference("RevitServices")
import RevitServices
from RevitServices.Persistence import DocumentManager

import System

doc = DocumentManager.Instance.CurrentDBDocument
#get list of categories loaded in the document
categories = doc.Settings.Categories

builtincats = []

for c in categories:
	bic = System.Enum.ToObject(BuiltInCategory, c.Id.IntegerValue) 
	builtincats.append(bic.ToString())
		
builtincats.sort()

OUT = builtincats