Python - '不能将序列乘以'str'类型的非整数'错误？ [复制]

Question

所以我正在开发一个代码，让用户输入产品的 GTIN-8 代码，输入他们想要的金额，然后提供收据。但是，当我到达代码的最后一部分时，我试图将产品的数量和价格相乘，我得到了“不能将序列乘以非 int 类型的‘str’错误。 以下是部分代码：

while IfFinished != "Yes":
    ProductsWanted=input("Please enter the GTIN-8 Code of the product: ")
    AmountOfProducts=input("How many do you want? ")

    with open("Productsfile.txt") as f:
        for line in f:
                if ProductsWanted in line:
                    Receipt=open("ReceiptFile.txt","a")
                    Receipt.write("%r, %r, \n" % (line, AmountOfProducts))
                    Receipt.close()

    if ProductsWanted not in ["23456945","12376988","76543111","92674769","43125999"]:
        print("Product not found")

    else:
        print("Product found")

    IfFinished=input("Are you done? If so, type 'Yes' ")
    if IfFinished == "Yes":
        print("Thank you for shopping with us!")
    else:
        print("Please continue")

Receipt=open("ReceiptFile.txt","r")
print(Receipt.read())
Receipt.close()

with open("ReceiptFile.txt","r") as file:
    for line in file:
        currentline=line.split(",")
quantity=currentline[3]
ItemPrice=currentline[2]
Totalprice=quantity*ItemPrice
price="0"
Total=price + Totalprice

print(Total)

Answer 1

这里，当你从文件中获取值时，它们是字符串类型的：

quantity=currentline[3]
ItemPrice=currentline[2]

在相乘之前需要将它们转换为int，例如：

quantity=int(currentline[3])