[Zope] Why is id sometimes a string and sometimes a function

[Robert Rottermann]

Hello all,

I am trying to create a function that reacts diferently depending in what
folder it is called.
No my problem:

if have to call
context.REQUEST.PARENTS[0].id()
however
context.REQUEST.PARENTS[1].id() creates an error, I have to use
context.REQUEST.PARENTS[1].id

why is this so??

Robert