bite_12.py

# Online Python - IDE, Editor, Compiler, Interpreter
from collections import namedtuple

User = namedtuple('User', 'name role expired')
USER, ADMIN = 'user', 'admin'
SECRET = 'I am a very secret token'

julian = User(name='Julian', role=USER, expired=False)
bob = User(name='Bob', role=USER, expired=True)
pybites = User(name='PyBites', role=ADMIN, expired=False)
USERS = (julian, bob, pybites)


# define exception classes here
class UserDoesNotExist(Exception):
    pass


class UserAccessExpired(Exception):
    pass


class UserNoPermission(Exception):
    pass


def get_secret_token(username):
    for user in USERS:
        if username == user.name:
            if user.expired:
                raise UserAccessExpired
            if user.role != ADMIN:
                raise UserNoPermission
            return SECRET
    raise UserDoesNotExist