How can I add loop in the python question with if and elif

Serendipity Booksellers has a book club that awards points to its customers based on the number of books purchased each month. The points are awarded as follows: • If a customer purchases 0 books, he or she earns 0 points. • If a customer purchases 2 books, he or she earns 5 points. • If a customer purchases 4 books, he or she earns 15 points. • If a customer purchases 6 books, he or she earns 30 points. • If a customer purchases 8 or more books, he or she earns 60 points. Write python program that asks the user to enter the number of books that he or she has purchased this month, then displays the number of points awarded. However, I would love to use while loop so that our user can use as many time as they can do unless it's qualified.