Getting the token of an ordered menu made by python menu script

[defc0n1]

Hey everyone

I have an ordered menu in my HDA that gets populated by a python script based on an attribute. The name of the menu is data_source:

if (geo.attribValue('nHDU') > 1):
    return ("0", "Primary", "1", "Extension")
else:
    return ("0", "Primary")

I'm trying to access this token value from an internal python node using this:

value = hou.evalParm("../data_source")

Now I know for sure that the nHDU value is >1 and the two menu items are being populated. Problem is, no matter what I select on the menu, I always get a value 0. It works if I add it directly to the ordered menu without using a script. But that defeats the purpose because it should depend on the attribute nHDU. Could someone tell me what's happening  here? Thanks.