RevitNotesCollector

import clr

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

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

doc = DocumentManager.Instance.CurrentDBDocument
uiapp = DocumentManager.Instance.CurrentUIApplication
app = uiapp.Application


collector = FilteredElementCollector(doc, doc.ActiveView.Id )

textNotesId = []
textNotes = []
textNotesId  = collector.OfClass(TextNote).ToElementIds()

for noteId in textNotesId:

    note = doc.GetElement(noteId)
    textNotes.append(note)

OUT = textNotes