python一个简单类例子的实现

LoadTest.py

class Loan:
    def __init__(self,annualInterestRate=2.5,numberOfYears=1,loadAmount=1000,borrower=" "):
        self.__annualInterestRate=annualInterestRate
        self.__numberOfYears=numberOfYears
        self.__loadAmount=loadAmount
        self.__borrower=borrower
    def getAnnualInterestRate(self):
        return self.__annualInterestRate
    def getNumberOfYears(self):
        return self.__numberOfYears
    def getLoadAmount(self):
        return self.__loadAmount
    def getBorrower(self):
        return self.__borrower

    def setAnnualInterestRate(self,annualInterestRate):
        self.__annualInterestRate=annualInterestRate
    def setNumberOfYears(self,numberOfYears):
         self.__numberOfYears=numberOfYears
    def setLoadAmount(self,loadAmount):
         self.__loadAmount=loadAmount
    def setBorrower(self,borrower):
        self.__borrower=borrower

    def getMonthlyPayment(self):
        monthInterestRate=self.__annualInterestRate/1200
        monthPayment= self.__loadAmount*monthInterestRate/(1-(1/(1+monthInterestRate)**(self.__numberOfYears*12)))
        return monthPayment

    def getTotalPayment(self):
        totalPayment=self.getMonthlyPayment()*self.__numberOfYears*12
        return

excercise.py

from LoanTest import Loan
def main():
    annualInterestRate=float(input("input  annualInterestRate ,for example,7.25:"))
    numberOfYears=eval(input("input numberOfYears "))
    loadAmount=eval(input("Enter loadAmount"))
    borrower=input("input the borrower's name")
    loan=Loan(annualInterestRate,numberOfYears,loadAmount,borrower)

    print("The loaner's name is "+loan.getBorrower())
    print("The monthly payment is "+format(loan.getMonthlyPayment(),".2f"))
    print("The total payment is "+format(loan.getTotalPayment(),".2f"))
main()

补充：
​​​pycharm导入本地py文件时，模块下方出现红色波浪线时如何解决​​

1. 进入设置，找到Console下的Python Console，勾选选项“Add source roots to PYTHONPAT”
2. 在当前项目程序目录右键单击，然后“Mark Directory as”为“Sources Root”。之后当前程序所在目录颜色会变化，表示已经完成标记。
   下图是我的补充，链接的博主没有给出很好的图解，我自己补充了一下