Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Basic Object-Oriented Python Emulating Built-ins Emulating Built-ins

I’ve added a Bookcase class inside bookcase.py. It will hold some books in a list. Add a __iter__ method so I can loop t

I’ve added a Bookcase class inside bookcase.py. It will hold some books in a list. Add a iter method so I can loop through the books. Use yield from and the book list inside the method.

book.py
class Book:
    def __init__(self, author, title):
        self.author = author
        self.title = title

    def __iter__(Bookcase)

    def __str__(self):
        return f'{self.author}, {self.title}'

    def __eq__(self, other):

        return self.author == other.author and self.title == other.title
bookcase.py
from book import Book


class BookCase:
    def __init__(self):
       self.books = []

    def add_books(self, book):
        self.books.append(book)

1 Answer

Steven Parker
Steven Parker
231,271 Points

Here's a few hints:

  • the instructions say to add the method to the Bookcase class inside bookcase.py (not to Book in book.py)
  • a "def" line should end with a colon character (:)
  • follow the hint in the instructions: "Use yield from and the book list inside the method"
  • review the lesson on __iter__ if you need to see an example of how it is used