Naive Django mptt branch copier

Surprisingly, it has not implemented in the project and end up to be customized one

Copy a full branch into another node · Issue #230 · django-mptt/django-mptt

I have a very simple graph here

class Question(MPTTModel):
   ...
   parent = TreeForeignKey('self', on_delete=models.CASCADE, null=True, blank=True, related_name='children')

My implementation is

def copy_question_node(instance: Question, plan: int = None, parent: Question = None) -> Question:
    """
    Copy the attribute of the `question` and return new instance without `parent`
    :param instance:
    :return:
    """
    kwargs = {}
    for attr in settings.ATTR_LIST:
        kwargs['plan'] = plan
        kwargs['parent'] = parent
        kwargs[attr] = getattr(instance, attr)
    return Question.objects.create(**kwargs)


def copy_children(target_branch: Question, parent: Question = None, new_node: bool = False) -> None:
    """
    :param target_branch: The original
    :return:
    """
    if new_node:
        new_node = copy_question_node(target_branch, parent=parent)
    else:
        new_node = parent
    for child in target_branch.children.all():
        # Make children of `plan` node
        new_child = copy_question_node(child, parent=new_node)
        copy_children(child, parent=new_child, new_node=False)

Method call example

def test_copy_branch(self):
    plan14 = Question.objects.get(id=82)
    copy_children(plan14, new_node=True)

You will get plan14 a new root node. Feel free to send me Email to correct my code if I am wrong or ping me if the django-mptt has an updated on it