app\models(15).py

#...

class User(db.Model, UserMixin):
  #...
  
    @staticmethod
    def add_self_follows():
        for user in User.query.all():
            if not user.is_following(user):
                user.follow(user)
                db.session.add(user)
                db.session.commit()
  
    @staticmethod
      def add_self_collection_follows():
          for user in User.query.all():
              for collection in user.collections:
                  if not user.is_following_collection(collection):
                      user.follow_collection(collection)
                      db.session.add(user)
                      db.session.commit()