Explain Python modules and packages.
2. What is Jaccard distance? Show by an example (not code).
3. Write a complete program that shows usage of two of the nltk library distance measures.
4. Write a Python class that represents book objects. A book has title, author(s), and year published. Implement appropriate constructor, getters (methods that can get fields, i.e., title, author(s), and year published), and setters (methods that set each field), and a __str__() method for printing book objects. Write code to test you Book class.