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![Nicholas Abate](https://uploads.teamtreehouse.com/production/profile-photos/11515146/micro_IMG_4884.jpg)
Nicholas Abate
1,643 PointsBook and Bookcase Relationship
How is it that in creating an instance using the classmethod create_bc that the title and author are passed to the Book class?
And we are appending a title and author to the books list. Would books = [title1, author1, title2, author2] in this case?
class Book:
def __init__(self, title, author):
self.title = title
self.author = author
def __str__(self):
return '{} by {}'.format(self.title, self.author)
class Bookcase:
def __init__(self, books = None):
self.books = books
@classmethod
def create_bc(cls, book_list):
books = []
for title, author in book_list:
books.append(Book(title, author))
return cls(books)
book1 = Bookcase.create_bc([("title1", 'author1'), ('title2', 'author2')]) print(book1.books[0])
1 Answer
![Steven Parker](https://uploads.teamtreehouse.com/production/profile-photos/969492/micro_tool_chess_set_2.jpg)
Steven Parker
230,688 PointsThe "create_bc" method doesn't just add strings to a list, it adds Book objects to a list that is an attribute of a "Bookcase" instance. So:
book1 = [title1, author1, title2, author2] # this is NOT what the example does
book1 = Bookcase([Book("title1", "author1"), Book("title2", "author2")]) # but this is