Python Programming

## # This module defines several classes that implement a banking account # class hierarchy. # ## A bank account has a balance and a mechanism for applying interest or fees at # the end of the month. # class BankAccount : ## Constructs a bank account with zero balance. # def __init__(self) : self._balance = 0.0 ## Makes a deposit into this account. # @param amount the amount of the deposit # def deposit(self, amount) : self._balance = self._balance + amount ## Makes a withdrawal from this account, or charges a penalty if # sufficient funds are not available. # @param amount the amount of the withdrawal # def withdraw(self, amount) : self._balance = self._balance - amount ## Carries out the end of month processing that is appropriate # for this account. # def monthEnd(self) : return ## Gets the current balance of this bank account. # @return the current balance # def getBalance(self) : return self._balance ## A savings account earns interest on the minimum balance. # class SavingsAccount(BankAccount) : ## Constructs a savings account with a zero balance. # def __init__(self) : super().__init__() self._interestRate = 0.0 self._minBalance = 0.0 ## Sets the interest rate for this account. # @param rate the monthly interest rate in percent # def setInterestRate(self, rate) : self._interestRate = rate ## Overrides superclass method. # def withdraw(self, amount) : super().withdraw(amount) balance = self.getBalance() if balance < self._minBalance : self._minBalance = balance ## Overrides superclass method. # def monthEnd(self) : interest = self._minBalance * self._interestRate / 100 self.deposit(interest) self._minBalance = self.getBalance() ## A checking account has a limited number of free deposits and withdrawals. # class CheckingAccount(BankAccount) : ## Constructs a checking account with a zero balance. # def __init__(self) : super().__init__() self._withdrawals = 0 ## Overrides superclass method. # def withdraw(self, amount) : FREE_WITHDRAWALS = 3 WITHDRAWAL_FEE = 1 super().withdraw(amount) self._withdrawals = self._withdrawals + 1 if self._withdrawals > FREE_WITHDRAWALS : super().withdraw(WITHDRAWAL_FEE) ## Overrides superclass method. # def monthEnd(self) : self._withdrawals = 0