So i have 3 categorys. first is without childs, second is always has a child but some times dosnt have parent and some times does
and third category is always without a parent.

And my goal is to go over this 3 categorys starting from bottom to top.

first i need to check category without child, second the secodn category and then third. 

if my condition is met i just desplay the message, if conditions not meet i go to another category and check for condition.

so i wrote this code and it's kinda ok, but maybe i could do it without repeating myself , and make my code more simple?

for line in order.order_line:
    parent_id = line.product_id.categ_id.parent_id
    parent_parent = line.product_id.categ_id.parent_id
    categ_id = line.product_id.categ_id
    categorys = parent_id + parent_parent + categ_id
categorys = parent_id + parent_parent + categ_id
for categ in categorys:
    if not categ.childs_id and categ.qty_for_discount:
        if line.product_qty < categ.qty_for_discount:
            msgs.append(
                msg % (
                    categ.qty_for_discount - line.product_qty,
                    line.product_id.uom_id.name,
                    categ.name
                )
            )
    elif categ.parent_id and categ.child_id and categ.qty_for_discount:
        if line.product_qty < categ.qty_for_discount:
            msgs.append(
                msg % (
                    categ.qty_for_discount - line.product_qty,
                    line.product_id.uom_id.name,
                    categ.name
                )
            )
    else:
        if line.product_qty < categ.qty_for_discount:
            msgs.append(
                msg % (
                    categ.qty_for_discount - line.product_qty,
                    line.product_id.uom_id.name,
                    categ.name
                )
            )