[web2py] How to know if you're getting a Set when you're expecting a dict?

[Bill Thayer]

<type 'exceptions.TypeError'> 'Set' object has no attribute '__getitem__' 

db.person._after_insert.append(lambda f,id: pprint(f,id)) #book's example

#my code in model file after table definition code.
db.extracted_linear._after_insert.append(
    lambda f, id:wiki_update_or_insert(
        'extracted_linear',
        f["name"],
        table_slug(f["name"]),
        id))

> The 
> book<http://web2py.com/books/default/chapter/29/06?search=_after_update>says 
> Here f is a dict of fields passed to insert or update, id is the id of 
> the newly inserted record, s is the Set object used for update or delete.

--