Question

当我注释掉for循环时，一切正常。但是，IDLE一旦再次激活，就会发出语法错误。我已经尝试过适当地将其间隔开，因为这是其他问题的建议之一，但是不管我按回车的次数多少，这都行不通。

# futval.py
# A program to compute the value of an investment
# carried 10 years into the future

#begins main function of program

def main():

    #description of program 

    print("This program calculates the future value")
    print("of a 10-year investment.")

    #creates and assign three variables to user input

    principal = eval(input("Enter the initial principal: "))
    apr = eval(input("Enter the annual interest rate: "))
    compound = eval(input("How often is the interest compounded: "))

    #begins a 'for' loop that iterates 10 times indicative of 10 years

    for i in range(10):
        print (principal)
        principal = principal * (1 + (apr/compound)

    #prints out the final result of the above equation. 
    print("The value in 10 years is:",principal)

    #original program exited too fast and didn't allow user to see output
    #I added the following line so the user could see.

    print(input("Press enter to exit."))

main()

Answer 1

您在)之后省略了(apr/compound)

for i in range(10):
        print (principal)
        principal = principal * (1 + (apr/compound))

Answer 2

语法错误是您缺少一个右括号：更改principal = principal * (1 + (apr/compound) 到principal = principal * (1 + (apr/compound))

此外，您应该摆脱使用eval的习惯，因为它通常被认为是危险的，在这里绝对不需要。只需将类型转换为类型并捕获异常即可。

Answer 3

您的代码缺少括号。否则，它将正常工作。

您的代码：

principal = principal * (1 + (apr/compound)

它应该是：`

principal = principal * (1 + (apr/compound))`

打印功能由于for循环而失败

3 个答案: