Context_processor未定义“”类/属性（错误）

Question

I am following a Django course from Antonio's Melle Book, and I need a context_processor to use a cart instance throught the webapp. I constantly get the error, that the context processor does not define a "cart" object attribute. Note: I am using cached sessions, if it matters

I tried putting the cart in a try catch statement, I have read the docs, I doesn't sort things out for me

context_processors.py

   from .cart import Cart
   def cart(request):
       return {'cart': Cart(request)}

settings.py

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
             (...)
            'cart.context_processors.cart,']}

cart.py class Cart(object):

    def __init__(self, request):
        self.session = request.session
        cart = self.session.get(settings.CART_SESSION_ID)
        if not cart:
            cart = self.session[settings.CART_SESSION_ID] = {}
        self.cart = cart

Answer 1

You haven't shown the actual error message. But the problem is probably because you've put the comma inside the quotes instead of outside. Change it to:

'cart.context_processors.cart',]}