Acceptable values for ACL principals

[Anton Novikov]

Hi,

I have Pyramid REST server with Cornice. This server implements authorization using ACLs. All principals are defined as strings, for example (example taken from here):

# The Cornice service.

bills_service = Service("bills", "/api/bills", factory=BillsListContext)

# The Context factory:

class BillListContext(object):

   def __init__(self, request):

       pass

    @property

   def __acl__(self):

       return [

           (Allow, "role:buyer", "get_bills"),

           (Allow, "role:seller", "get_bills"),

       ]

# And the view function is then:

@bills_service.get(

   content_type="application/json",

   accept="application/json",

   permission="get_bills",

   )

def get_bills(request):

   # …

According to the documentation, principal is expected to be a string or Unicode object. However, i wonder if this limitation is necessary, because i couldn't find any place requiring principal to be a string (or Unicode object).
What i want is to use enum values for principals. I know, it's possible to create enum which inherits from `str` type, however i'm curious if i'm really limited by `str` type for principals.

Regards,
Anton