# filling the carts
carts = {}
for customer in customers:
carts[customer] = []
for article, quantity in shopping_lists[customer]:
if article in supermarket:
if supermarket[article]["quantity"] < quantity:
quantity = supermarket[article]["quantity"]
if quantity:
supermarket[article]["quantity"] -= quantity
carts[customer].append((article, quantity))
for customer in customers:
print("checkout for " + customer + ":")
total_sum = 0
for name, quantity in carts[customer]:
unit_price = supermarket[name]["price"]
item_sum = quantity * unit_price
print( "{0:3d} {1:12s} {2:8.2f} {3:8.2f}".format(quantity, name, unit_price, item_sum))
total_sum += item_sum
print("{0:22s} {1:11.2f}".format("total_sum:", total_sum))