Question

我有一项家庭作业，基本上是创建一个超市结帐程序。它必须询问用户它们有多少个项目，然后输入项目名称和成本。这一点我做得很好，但是我很难将总数相加。

最后一行代码不会将价格加在一起，而只是列出价格。

到目前为止的代码

print "Welcome to the checkout! How many items will you be purchasing?"
number = int (input ())

grocerylist = []
costs = []

for i in range(number):
    groceryitem = raw_input ("Please enter the name of product %s:" % (i+1))
    grocerylist.append(groceryitem)
    itemcost = raw_input ("How much does %s cost?" % groceryitem)
    costs.append(itemcost)

print ("The total cost of your items is " + str(costs))

这是我正在做的SKE的一项家庭作业，但是由于某种原因我很沮丧！

预期输出是在程序结束时，将显示添加到程序中并带有£符号的项目的总成本。

Answer 1

您必须遍历列表以求和：

...
total = 0
for i in costs:
    total += int(i)
print ("The total cost of your items is " + str(total)) # remove brackets if it is python 2

替代方法（对于python 3）：

print("Welcome to the checkout! How many items will you be purchasing?")
number = int (input ())

grocerylist = []
costs = 0   # <<

for i in range(number):
    groceryitem = input ("Please enter the name of product %s:" % (i+1))
    grocerylist.append(groceryitem)
    itemcost = input ("How much does %s cost?" % groceryitem)
    costs += int(itemcost)   # <<
print ("The total cost of your items is " + str(costs))

输出：

Welcome to the checkout! How many items will you be purchasing?
2
Please enter the name of product 1:Item1
How much does Item1 cost?5
Please enter the name of product 2:Item2
How much does Item2 cost?5
The total cost of your items is 10

Answer 2

您需要将费用声明为int，然后将其加起来：

print("Welcome to the checkout! How many items will you be purchasing?")
number = int(input ())

grocerylist = []
costs = []

for i in range(number):
    groceryitem = input("Please enter the name of product %s:" % (i+1))
    grocerylist.append(groceryitem)
    itemcost = input("How much does %s cost?" % groceryitem)
    costs.append(int(itemcost))

print ("The total cost of your items is " + str(sum(costs)))

raw_input似乎也有问题。我将其更改为input。

如何将跑步总数加在一起？

2 个答案: