[contravariant]

Best way to think about it is that a generator can throw some questions back to the caller. It always looks a bit messy though.

    question_bank={'1+1' : '2', '2+3' : '5'}

    def Quiz():
        for question, correct_answer in question_bank.items():
            answer = yield question
            if answer == correct_answer:
                print('Correct!')
            else:
                print('Wrong.')
        yield 'Finished!'
                
    question = Quiz()
    q = next(question)
    while q != 'Finished!':
        q = question.send(input(q))