__getattr__, @property, дексрипотор

"""
СВОЙСТВА PROPERTY
"""

class CardHolder:
    acctlen = 8
    retireage = 59.5

    def __init__(self, acct, name, age, addr):
        self.acct = acct
        self.name = name
        self.age = age
        self.addr = addr

    def getName(self):
        return self.__name
    def setName(self, value):
        value = value.lower().replace(' ', '_')
        self.__name = value
    name = property(getName, setName)

    def getAge(self):
        return self.__age
    def setAge(self, value):
        if value < 0 or value > 150:
            raise ValueError('invalid age')
        else:
            self.__age = value
    age = property(getAge, setAge)

    def getAcct(self):
        return self.__acct[:-3] + '***'
    def setAcct(self, value):
        value = value.replace('-', '')
        if len(value) != self.acctlen:
            raise TypeError('invalid acct number')
        else:
            self.__acct = value
    acct = property(getAcct, setAcct)

    def remainGet(self):
        return self.retireage - self.age
    remain = property(remainGet)




"""
ДЕСКРИПТОРЫ
"""

class CardHolder:
    acctlen = 8
    retireage = 59.5

    def __init__(self, acct, name, age, addr):
        self.acct = acct
        self.name = name
        self.age = age
        self.addr = addr

    class Name:
        def __get__(self, instance, owner):
            return self.name
        def __set__(self, instance, value):
            value = value.lower().replace(' ', '_')
            self.name = value
    name = Name()

    class Age:
        def __get__(self, instance, owner):
            return self.age
        def __set__(self, instance, value):
            if value < 0 or value > 150:
                raise ValueError('invalid age')
            else:
                self.age = value
    age = Age()

    class Acct:
        def __get__(self, instance, owner):
            return self.acct[:-3] + '***'
        def __set__(self, instance, value):
            value = value.replace('-', '')
            if len(value) != instance.acctlen:
                raise TypeError('invalid acct number')
            else:
                self.acct = value
    acct = Acct()

    class Remain:
        def __get__(self, instance, owner):
            return instance.retireage - instance.age
        def __set__(self, instance, value):
            raise TypeError('cannot set remain')
    remain = Remain()




"""
__getattr__
"""

class CardHolder:
    acctlen = 8
    retireage = 59.5

    def __init__(self, acct, name, age, addr):
        self.acct = acct
        self.name = name
        self.age = age
        self.addr = addr

    def __getattr__(self, name):
        if name == 'acct':
            return self._acct[:-3] + "***"
        elif name == 'remain':
            return self.retireage - self.age
        else:
            raise AttributeError(name)

    def __setattr__(self, name, value):
        if name == 'name':
            value = value.lower().replace(' ', '_')
        elif name == 'age':
            if value < 0 or value > 150:
                raise ValueError('invalid age')
        elif name == 'acct':
            name = '_acct'
            value = value.replace('-', '')
            if len(value) != self.acctlen:
                raise TypeError('invalid acct number')
        elif name == 'remain':
            raise TypeError('cannot set remain')
        self.__dict__[name] = value




"""
__getattribute__
"""

class CardHolder:
    acctlen = 8
    retiareage = 59.5

    def __init__(self, acct, name, age, addr):
        self.acct = acct
        self.name = name
        self.age = age
        self.addr = addr

    def __getattribute__(self, name):
        superget = object.__getattribute__
        if name == 'acct':
            return superget(self, 'acct')[:-3] + '***'
        elif name == 'remain':
            return superget(self, 'retiareage') - superget(self, 'age')
        else:
            return superget(self, name)

    def __setattr__(self, name, value):
        if name == 'name':
            value = value.lower().replace(' ', '_')
        elif name == 'age':
            if value < 0 or value > 150:
                raise ValueError('invalid age')
        elif name == 'acct':
            value = value.replace('-', '')
            if len(value) != self.acctlen:
                raise TypeError('invalid acct number')
        elif name == 'remain':
            raise TypeError('cannot set remain')
        self.__dict__[name] = value