arcpy - Labeling one to many relationship class using ArcGIS for Desktop?

I’ve created a feature class with a one to many relationships to a table.

One point many classes.

However I want to label the point with the classes attributes.

Esri wrote VB solution but it's not supported at version 10.1.

Answer

i found the answer here at wolf mapper blog - right click on the point shapefile and select “Properties” > “Labels” tab > “Expression…” button. In the “Label Expression” window select “Python” as the “Parser:” and click the check-box next to “Advanced.” Insert the following code:

    def FindLabel ( [LocID] ):

   import arcpy
   myDataTable = "data table" #insert data table name
   myComponent = "Arsenic" #insert component name
   myScreeningLevel = "32" #insert exceedance  level
   myQuerySelect = '"location_id"' + " = '" + [LocID] + "' and " + '"component"' + " like '" + myComponent + "%'"
   myFieldsQuerySelect = "OBJECTID; location_id; component; top_depth_inches; bottom_depth_inches; result; units"

   mySortQuerySelect = "top_depth_inches"
   myText = ""

   mxd = mxd = arcpy.mapping.MapDocument("CURRENT")

   for table in arcpy.mapping.ListTableViews(mxd):
     if table.name == myDataTable:
       rows = arcpy.SearchCursor(table, myQuerySelect, "", myFieldsQuerySelect, mySortQuerySelect)
       myText = "" + [LocID] + "\n" + "" + myComponent + "" + "\n"
       currentState = ""

       for row in rows:
         if currentState != row.OBJECTID:
           currentState = row.OBJECTID
         if float(row.result) >= float(myScreeningLevel):
           myText = myText + str(int(row.top_depth_inches)) + '"-' + str(int(row.bottom_depth_inches)) + "" " + str(row.result) + " " + str(row.units) + "\n"
         else:
           myText = myText + str(int(row.top_depth_inches)) + '"-' + str(int(row.bottom_depth_inches)) + '" ' + str(row.result) + " " + str(row.units) + "\n"

       return myText