def bulk_item_promo(order):
    discount = 0
    for item in order.cart:
        if item.quantity >= 20:
            discount += item.total() * .1
    return discount
10% discount for each LineItem with 20 or more units
dataset/ETHPy150Open fluentpython/example-code/06-dp-1class-func/strategy_best.py/bulk_item_promo