accounts.py

# the SavingsAccount class represents a 
# savings account.

class SavingsAccount:
    
    # the __init__ method accepts arguments for the
    # account number, interest rate, and balance.
    
    def __init__(self, account_num, int_rate, bal):
        self.__account_num=account_num
        self.__interest_rate=int_rate
        self.__balance=bal
        
    # the following methods are mutators for the
    # data attributes.
    
    def set_account_num(self, account_num):
        self.__account_num=account_num
        
    def set_interest_rate(self, int_rate):
        self.__interest_rate=int_rate
        
    def set_balance(self, bal):
        self.__balance=bal 
        
    # The following methods are accessors for the
    # data attributes.

    def get_account_num(self):
        return self.__account_num

    def get_interest_rate(self):
        return self.__interest_rate

    def get_balance(self):
        return self.__balance
        
# the CD account represents a certificate of
# deposit (CD) account. it is a subclass of
# the SavingsAccount class.

class CD(SavingsAccount):
    
    # the __init__ method accepts arguments for the
    # account number, interest rate, balance, and
    # maturity date.
    
    def __init__(self, account_num, int_rate, bal, mat_date):
        # call the superclass __init__ method
        SavingsAccount.__init__(self, account_num, int_rate, bal)
        
        # initialize the __maturity_date attribute.
        self.__maturity_date=mat_date
        
    # the set_maturity_date is a mutator for the
    # __maturity_date attribute.
    def set_maturity_date(self, mat_date):
        self.__maturity_date=mat_date
        
    # the get_maturity_date method is an accessor
    # for the _maturity_date attribute.
    def get_maturity_date(self):
        return self.__maturity_date