Question

Chapter 7, Problem 3PE from Introduction to Programming using Python by Y. Daniel Liang.

Problem

(The Account class) Design a class named Account that contains:

■ A private int data field named id for the account.

■ A private float data field named balance for the account.

■ A private float data field named annualInterestRate that stores the current interest rate.

■ A constructor that creates an account with the specified id (default 0), initial balance (default 100), and annual interest rate (default 0).

■ The accessor and mutator methods for id, balance, and annualInterestRate.

■ A method named getMonthlyInterestRate() that returns the monthly interest rate.

■ A method named getMonthlyInterest() that returns the monthly interest.

■ A method named withdraw that withdraws a specified amount from the account.

■ A method named deposit that deposits a specified amount to the account.

Draw the UML diagram for the class, and then implement the class. (Hint: The method getMonthlyInterest() is to return the monthly interest amount, not the interest rate. Use this formula to calculate the monthly interest: balance * monthlyInterestRate. monthlyInterestRate is annualInterestRate / 12. Note that annualInterestRate is a percent (like 4.5%). You need to divide it by 100.)

Write a test program that creates an Account object with an account id of 1122, a balance of $20,000, and an annual interest rate of 4.5%. Use the withdraw method to withdraw $2,500, use the deposit method to deposit $3,000, and print the id, balance, monthly interest rate, and monthly interest.

Answer 1

#CODE FOR THE PROBLEM

class Account:

    __id=None

    __balance=None

    __annualInterestRate=None

    def __init__(self, id=0, balance=100, interest=0):

        self.__id=id

        self.__balance=balance

        self.__annualInterestRate=interest

    def getID(self):

        return self.__id

    def setID(self, id):

        self.__id=id

    def getBalance(self):

        return self.__balance

    def setBalance(self, balance):

        self.__balance=balance

    def getAnnualInterestRate(self):

        return self.__annualInterestRate

    def setAnnualInterestRate(self, interest):

        self.__annualInterestRate=interest

    

    def getMonthlyInterestRate(self):

        return self.__annualInterestRate/12

    def getMonthlyInterest(self):

        return (self.__balance*self.__annualInterestRate)/1200

    def withdraw(self, amount):

        if(self.__balance>=amount):

            self.__balance-=amount

            print("Successfully Withdrawn")

        else:

            print("Insufficient Balance")

    def deposit(self, amount):

        self.__balance+=amount

    

#following codes are to test the working of the class

account = Account(1122, 20000, 4.5)

x = account.getID()

print("ID is "+str(x))

account.setID(1155)

x = account.getID()

print("Updated ID is "+ str(x))

x = account.getBalance()

print("Balance is $"+ str(x))

x = account.setBalance(15000)

x = account.getBalance()

print("Updated Balance is $"+ str(x))

x = account.getAnnualInterestRate()

print("Annual Interest Rate is "+ str(x))

x = account.setAnnualInterestRate(6)

x = account.getAnnualInterestRate()

print("Updated Annual Interest Rate is "+ str(x))

x = account.getMonthlyInterestRate()

print("Monthly Interest Rate is "+str(x))

x = account.getMonthlyInterest()

print("Monthly Interest is "+str(x))

account.withdraw(5000)

x=account.getBalance()

print("New balance after withdrawing 5000 is "+str(x))

account.deposit(2000)

x=account.getBalance()

print("New balance after depositing 2000 is "+str(x))

# IF YOU GET INDENTATION ERROR, CHECK THE ATTACHED IMAGE