AttributeError: 'list' object has no attribute '_sa_instance_state'

Question

I get the following error, and I\'m not sure how to fix it. I think it\'s related to the is_bestfriend relationship.

File \"/usr/local/lib/pyth         


        

Answer 1

You are assigning a list to a relationship where uselist=False. You should set the single model instance, rather than a list containing it.

def be_bestfriend(self, user):
    if not self.are_bestfriends(user):
        self.is_bestfriend = user
        user.is_bestfriend = self
        return self