Readable double self join / tree traversal in SQLAlchemy

selfjoin.py

FourDigit = aliased(HSProduct)
TwoDigit = aliased(HSProduct)
Section = aliased(HSProduct)

product_data = db.session\
    .query(
        FourDigit.id.label("product_id"),
        FourDigit.code.label("product_code"),
        FourDigit.name_en.label("product_name"),
        Section.id.label("section_id"),
        Section.code.label("section_code"),
        Section.name_en.label("section_name"),
    )\
    .join(TwoDigit, FourDigit.parent_id == TwoDigit.id)\
    .join(Section, TwoDigit.parent_id == Section.id)\
    .order_by(Section.name_short_en)\
    .all()
product_data = {x.product_id: x._asdict() for x in product_data}