[PYTHON]: Write the class Book that stores the title, author and number of pages of a book. Write the class method inventory() that returns the number of instances created. Write the special (or magic) methods, str, del and len that will return information to the user in the format shown below.

>>>book1 = Book("Beneath a Scarlet Sky", "Mark Sullivan", 526)

>>>book2 = Book("Love in the Time of Cholera", "Gabriel G. Marquez", 357)

>>>book3 = Book("We Were the Lucky Ones", "Georgia Hunter", 414)

>>>Book.inventory()

3

>>>print(book1)

TITLE: Beneath a Scarlet Sky by Mark Sullivan

>>>len(book1)

526

>>>del book1

>>>Book.inventory()

2