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

Zachary Radcliff
Zachary Radcliff
4,276 Points
Posted by Zachary Radcliff
Zachary Radcliff
4,276 Points

__str__ assertion error

I can not seem to find out why my code is breaking..

book.py 
class Book:
    def __init__(self, author, title):
        self.author = author
        self.title = title
    def __str__(self):
        return self.author, self.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
231,269 Points
Steven Parker
Steven Parker
231,269 Points

The instructions ask you to "Return a string with the author and title of the book.", but this code is returning a tuple instead.