from dataclasses import dataclass @dataclass class Book_list: name: str perunit_cost: float quantity_available: int = 0 # function to calculate total cost def total_cost(self) -> float: return self.perunit_cost * self.quantity_available book = Book_list("Introduction to programming.", 300, 3) x = book.total_cost() # print the total cost # of the book print(x) # print book details print(book) # 900 Book_list(name='Python programming.', perunit_cost=200, quantity_available=3)