Strange error with getattr() function

[Hole]

Hi There!

I'm trying to use Zope and the product OpenFlow.

I got the following error while I was using the built-in function
getattr() to retrieve an OpenFlow object:

attribute name must be string


Actually, I surely pass a string as attribute name to getattr()

The code:

#following instruction returns me the string "WorkFlowTest"
openflow_id=container.aq_parent.id

if (hasattr(container,openflow_id):
    #the interpreter enter in this block, so
    #it's sure that container has an attribute called WorkFlowTest
    openflow=getattr(container,openflow_id)

At this point, I got the error: attribute name must be string

The *strange* is that I get the same error even if I pass the attribute
name to the getattr() function as pure string:

getattr(container,"WorkFlowTest")

(sic!!!!!)

I'm a lot confused!
Thanks in advance.

-- 
H0le