from collections import namedtuple
Book = namedtuple('Book', 'author title genre year price instock')
books = [Book('Suzane Collins', 'The Hunger Games', 'Fiction', 2008, 6.96, 
    20), Book('J.K. Rowling', "Harry Potter and the Sorcerer's Stone",
    'Fantasy', 1997, 4.78, 12)]
for i in range(len(books)):
    books[i] = books[i]._replace(price=books[i].price * 1.1)
print(books[i].price)
Changing values of a list of namedtuples