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

Leslio McKeown
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Leslio McKeown
Python Development Techdegree Student 9,389 Points

it keeps saying Bummer: AttributeError: 'BookCase' object has no attribute 'books'

Bummer: AttributeError: 'BookCase' object has no attribute 'books'

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):
        if self.author == other.author and self.title == other.title:
            return True
        else:
            return False
bookcase.py
from book import Book


class BookCase:

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

    def __iter__(self):
        yield from self.books

2 Answers

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,031 Points

Hey Leslio McKeown, the attribute books needs to be defined in the class BookCase.

Similar to the Book class, and an __init__ method to BookCase that sets self.books = []

Post back if you need more help. Good luck!!!

Leslio McKeown
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.a{fill-rule:evenodd;}techdegree
Leslio McKeown
Python Development Techdegree Student 9,389 Points

by defined is it self.books = books?

because I'm still not understanding it even after rewatching the videos

I'm getting a new error message: TypeError: init() missing 1 required positional argument: 'books'

Chris Freeman
Chris Freeman
Treehouse Moderator 68,031 Points

In the add_books method, book instances are append to self.books So, self.books should be initialized as an empty set [].

Create the missing __init__ method with the BookCase class.

class BookCase:

    # Add missing __init__ method here

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

    def __iter__(self):
        yield from self.books
Leslio McKeown
seal-mask
.a{fill-rule:evenodd;}techdegree
Leslio McKeown
Python Development Techdegree Student 9,389 Points

this doesn't seem to work it shows: Bummer: TypeError: init() missing 1 required positional argument: 'books'

class BookCase:

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

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

    def __iter__(self):
        yield from self.books

[MOD: added ```python formatting -cf]

Chris Freeman
Chris Freeman
Treehouse Moderator 68,031 Points

When I pasted your code into the challenge, it passed for me.