Question

运营商％d似乎在这里工作正常

print("The value in 10 years is $%d. Don't spend it all in one place!") % (principal)

main()

然而，它在这里不起作用：

 x = int(input("Enter how many years you would to calculate the future value of $%d. \nPlease choose at least 10 years: " ))  % principal

这里是完整的代码：

def main():
    #Describes the program
    print("This program calculates the future value")
    print("of a 10-year investment.")

    #Prompts the user to enter a principal amount
    principal = int(input("Enter the initial principal: "))

    x = int(input("Enter how many years you would to calculate the future value of $%d. \nPlease choose at least 10 years: " ))  % principal
    #loops through 10 periods, years in this case
    for i in range( x ):
        #calculates the new principal based on the interest
        principal = principal * (1 + 0.75)

     #prints the value and %d is a placeholder to format the integer
    print("The value in 10 years is $%d. Don't spend it all in one place!") % (principal)
    main()

我是否缺少此操作符的范围，或者它是否只是使用不正确且格式应完全不同？

Answer 1

您的代码不正确：

x = int(input("Enter how many years you would to calculate the future value of $%d. \nPlease choose at least 10 years: " ))  % principal

您应该将其替换为：

x = int(input("Enter how many years you would to calculate the future value of $%d. \nPlease choose at least 10 years: " % principal))

或使用format()：

x = int(input("Enter how many years you would to calculate the future value of ${}. \nPlease choose at least 10 years: ".format(principal)))

此外，此代码也不正确：

print("The value in 10 years is $%d. Don't spend it all in one place!") % (principal)

您可以通过以下方式替换它：

print("The value in 10 years is $%d. Don't spend it all in one place!" % principal)

或使用format()：

print("The value in 10 years is ${}. Don't spend it all in one place!".format(principal))

<强> NB：

%d会将您的principal变量格式化为integer = int 您可以使用%f并将其格式化为float以获得更好的效果。

Answer 2

试试这个：

print("The value in 10 years is $" + str(principal) + ". Don't spend it all in one place!")

并且不要忘记将函数main（）移到函数定义之外。

％d运算符不在python 3.x中运行

2 个答案: