Вы пропустили добавление self
в bag_products
.
заменить
def bag_products(product_list):
с
def bag_products(self, product_list):
Редактировать в соответствии с комментариями
product_list = {'Name': ['Milk, 2 Litres', 'Bread', 'Sugar', 'Apple'], 'Price': ['2.0', '3.5', '3.0', '4.5'], 'weight': ['2', '0.6', '2.8', '4.2']}
class Weightcheck:
def bag_products(self, product_list):
bag_list = []
non_bag_items = []
MAX_BAG_WEIGHT = 5.0
for w in product_list['weight']:
if float(w) > MAX_BAG_WEIGHT:
bag_list.append(w)
non_bag_items.append(w)
print(bag_list)
print(non_bag_items)
demo = Weightcheck()
demo.bag_products(product_list)