a.display()
book1 = Book('957-4-36-547417-1', 'Learn Physics', 'Stephen', 'CBC', 350, 200,
10)
book2 = Book('652-6-86-748413-3', 'Learn Chemistry', 'Jack', 'CBC', 400, 220,
20)
book3 = Book('957-7-39-347216-2', 'Learn Maths', 'John', 'XYZ', 500, 300, 5)
book4 = Book('957-7-39-347216-2', 'Learn Biology', 'Jack', 'XYZ', 400, 200, 6)
book1.display()
book1.sell()
books = [book1, book2, book3, book4]
for i in range(4):
books[i].display()
book_title_list = [books[i].title for i in range(4)]
print(book_title_list)
a = Fraction(-2)
a.show()
f1 = Fraction(2, 3)
f1.show()
f2 = Fraction(3, 4)
f2.show()
f3 = f1.multiply(f2)
f3.show()
f3 = f1.add(f2)
f3.show()
f3 = f1.add(5)
f3.show()
f3 = f1.multiply(5)
f3.show()
class Product():
