class Dal(object):
    def select(self):
        print("call daladapter")

class IStorage(Interface):
    def select():
        """call storage"""

class StorageFoo(object):
    implements(IStorage)
    def select(self):
        print("call storage foo")

class StorageBaz(object):
    implements(IStorage)
    def select(self):
        print("call storage baz")

class Database(dict):
    def __init__(self):
        pass

    def __getattr__(self, key):
        return self[key]


    def __setattr__(self, key, value):
        if key[:1] !='_' and key in self:
            raise SyntaxError('Object %s exists and cannot be redefined' % key)
        dict.__setitem__(self, key, value)

request.registry.registerAdapter([Dal], IStorage, "foo", StorageFoo())
request.registry.registerAdapter([Dal], IStorage, "baz", StorageBaz())