decorators1.py

class User:
    def __init__(self, firstname='John', lastname='Smith', is_admin=False):
        self.firstname = firstname
        self.lastname = lastname
        self.is_admin = is_admin

    def __str__(self):
        return "User[%s %s%s]" % (self.firstname, self.lastname,
            ' Administrator' if self.is_admin else '')


def postlist(user):
    if user:
        return 'This is the public postlist of user %s %s' % (user.firstname, user.lastname)
    return None

def userlist(user):
    return 'This is the whole registered user list. [Sensitive data]'

def inventory(user):
    return 'This is the inventory resource. [Sensitive data]'


# Tests

stan = User('Stan', 'Smith', False)
peter = User('Peter', 'Griffin', True)

assert postlist(None) is None
assert postlist(stan) is not None
assert postlist(peter) is not None

assert userlist(None) is None
assert userlist(stan) is None
assert userlist(peter) is not None

assert inventory(None) is None
assert inventory(stan) is None
assert inventory(peter) is not None