Python

# What a cart costs.
def subtotal(items,tax = 0.2):
    return sum( item.price*item.quantity for item in items )*(1+tax)
def label(item): return item.name+' x'+str(item.quantity)

# What a cart costs.
def subtotal(items, tax=0.2):
    return sum(item.price * item.quantity for item in items) * (1 + tax)


def label(item):
    return item.name + " x" + str(item.quantity)