# other imports
from mptt.models import MPTTModel, TreeForeignKey
from mptt.managers import TreeManager

class SectionManager(TreeManager):
def get_queryset(self):
    return super().get_queryset().filter(published=True)

class Section(MPTTModel):
    published = models.BooleanField(
    default=True,
    help_text="If unpublished, this section will show only"
              " to editors. Else, it will show for all."
)

objects = TreeManager()
published_objects = SectionManager()

# show all objects
Section.objects.count()  # result is correct - 65
Section.objects.root_nodes().count() # result is correct - 12

# show published objects, just one is not published.
Section.published_objects.count() # result is correct - 64
Section.published_objects.root_nodes().count()  # result is corrct - 12

for root in Section.objects.root_nodes():
    print(f"root_section_{root.id} has {root.get_children().count()} children")

    # results ...
    root_section_57 has 13 children # correct - 13 items
    # ... more results

for root in Section.published_objects.root_nodes():
    print(f"root_section_{root.id} has {root.get_children().count()} children")

    # results ...
    root_section_57 has 13 children # WRONG - should be only 12 children
    # ... more results