Question

这本书说增强后应该看起来像这样。

Welcome to the future value calculator

enter monthly investment: 0
Entry must be greater than 0 . Please try again.
enter monthly investment: 100
enter yearly interest rate: 16
Entry must be greater than 0 and less than or equal to 15. Please try again.
enter yearly interest rate: 12
Enter number of years: 100
Entry must be greater than 0 and less than or equal to 50
please try again.
enter number of years: 10

Year = 1 Future Value = 1280.93
Year = 2 Future VAlue = 2724.32
Year = 3 Future Value = 4350.76
Year = 4 Future Value = 6183.48
Year = 5 Future Value = 8248.64
Year = 6 Future Value = 10575.7
Year = 7 Future Value = 13197.9
Year = 8 Future Value = 16152.66
Year = 9 Future Value = 19482.15
Year = 10 Future Value = 23233.91

Continue (y/n)?

这就是我程序中的内容

#!/usr/bin/env python3

# display a welcome message
print("Welcome to the Future Value Calculator")
print()

choice = "y"
while choice.lower() == "y":

    # get input from the user
    monthly_investment = float(input("Enter monthly investment:\t"))
    yearly_interest_rate = float(input("Enter yearly interest rate:\t"))
    years = int(input("Enter number of years:\t\t"))

    # convert yearly values to monthly values
    monthly_interest_rate = yearly_interest_rate / 12 / 100
    months = years * 12

    # calculate the future value
    future_value = 0
    for i in range(months):
        future_value += monthly_investment
        monthly_interest_amount = future_value * monthly_interest_rate
        future_value += monthly_interest_amount

    # display the result
    print("Future value:\t\t\t" + str(round(future_value, 2)))
    print()

    # see if the user wants to continue
    choice = input("Continue (y/n)? ")
    print()

print("Bye!")

为每月投资条目添加数据验证。使用while循环检查条目的有效性，并保持循环直到条目有效。有效的投资金额必须大于零，否则必须显示如上所示的错误消息。
使用相同的技术来添加利率和年限的数据验证。利率必须大于零且小于或等于15。年份必须大于零且小于或等于50。对于每个无效条目，显示并显示相应的错误消息。完成后，将有三个while循环和一个for循环嵌套在另一个while循环中。
修改for循环中用于计算将来值的语句，以便每年显示一行，并显示年份和将来值，如图所示。以上。为此，您需要使用range（）函数返回的整数。

我不确定将while循环放在哪里开始增强。

Answer 1

请检查以下代码，让我知道它是否有效。

#!/usr/bin/env python3

    # display a welcome message
    print("Welcome to the Future Value Calculator")
    print()

    choice = "y"
    while choice.lower() == "y":

        # get input from the user
        while True:
            monthly_investment = float(input("Enter monthly investment:  "))
            if monthly_investment <= 0 :
                print("Entry must be greater than 0 . Please try again.")
                continue
            else:
                break

        while True:
            yearly_interest_rate = float(input("Enter yearly interest rate:  "))
            if yearly_interest_rate <= 0  or yearly_interest_rate >= 15:
                print("Entry must be greater than 0 and less than or equal to 15. Please try again.")
                continue
            else:
                break

        while True:
            years = int(input("Enter number of years: "))
            if years <= 0 or years >= 50:
                print("Entry must be greater than 0 and less than or equal to 50")
                continue
            else:
                break

         # convert yearly values to monthly values
        monthly_interest_rate = yearly_interest_rate / 12 / 100
        months = years * 12

        # calculate the future value
        future_value = 0
        for i in range(1,months+1):
            future_value += monthly_investment
            monthly_interest_amount = future_value * monthly_interest_rate
            future_value += monthly_interest_amount
            if i % 12 ==0:
            # display the result
                print("Year = {0} Future value:\t{1}".format(i//12,str(round(future_value, 2))))



        # see if the user wants to continue
        choice = input("Continue (y/n)? ")
        print()

    print("Bye!")

murach python循环增强挑战

1 个答案: