将字符串更改为整数时出现值错误[重复]

Question

每当我运行以下代码时，都会出现值错误。如何将以下代码从字符串更改为整数？谢谢

v1 = "5"
v2 = "3"

#covert to int 
v1 = int(v1)
v2 = int(v2)

#save the sum of v1 and v2 into to var total
total = v1 + v2

print("The sum of :", v1 , "and", v2, "is", total)

或选项 2

v1 = input("Please enter a number: ")
v1 = int(v1) 
v2 = input("Please enter a number: ")
v2 = int(v2)

#save the sum of v1 and v2 into to var total
total = v1 + v2

print("The sum of :", v1 , "and", v2, "is", total)

Answer 1

您可能想要更改引号之间的提示。输入需要使用键盘输入，引号之间的短语是您在输入时会看到的提示。

这样，系统将提示您先输入变量v1，然后再输入变量v2。你应该确保你没有输入任何空格或字符串，只输入你想要求和的数字。或者，您还可以实现一个系统来检查用户输入是否为数字，否则，请用户再次输入数字。

选项 1 将是：

v1 = input ('Please Introduce the first number')

v1 = int(v1)

v2 = input('Please introduce the second number')

v2 = int(v2)

total = int(v1) + int(v2)

print ("the sum of", v1, "and", v2, "is?", total )

选项 2（检查用户是否输入了数字）：

correctNumbers = False

while (not correctNumbers):

    try:
        v1 = input ('Please introduce the first number')
        v2 = input ('Please introduce the second number')
        v1 = int(v1)
        v2 = int(v2)
        correctNumbers=True
    except:
        print ("At least one of the two numbers contained a wrong character, please try again.")

total = int(v1) + int(v2)

print ("the sum of", v1, "and", v2, "is?", total )

我希望它有助于解决您的疑问:)