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'm getting Assertion Error: False is not true: Make sure you have __iter_ method in your class. What am I doing wrong ?

class Book: def init(self, author, title): self.author = author self.title = title

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

def __eq__(self, other):
    return self.author == other.author and self.title == other.title

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

    def __iter__ (self):
        yield from self.books

    def add_book(self, book):
        self.books.append(Book)

book = Book('John Green', 'Paper Town')

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

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

    def __eq__(self, other):
        return self.author == other.author and self.title == other.title

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

        def __iter__ (self):
            yield from self.books

        def add_book(self, book):
            self.books.append(Book)

book = Book('John Green', 'Paper Town')
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

The code for "Bookcase" should exist only within bookcase.py, don't duplicate it in book.py.

Also, there should be no space between "__iter__" and the parenthesis