ИваСерж спасибо за наводку, вот что получилось
import clr
clr.AddReference("RevitAPI")
from Autodesk.Revit.DB import *
clr.AddReference("RevitServices")
import RevitServices
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
clr.AddReference("RevitNodes")
doc = DocumentManager.Instance.CurrentDBDocument
x=IN[0]
TransactionManager.Instance.EnsureInTransaction(doc)
if isinstance(x, list) == True:
family= [doc.LoadFamily(i) for i in x]
else:
family = doc.LoadFamily(x)
#doc.LoadFamily(FamilyPath)
TransactionManager.Instance.TransactionTaskDone()
OUT=family