Python-сообщество

class C1(object):
    def __init__(self):
        self._p1 = 1
    def p1_get(self):
        return self._p1
    def p1_set(self, v):
        self._p1 = v
    p1 = property(p1_get, p1_set)

class C2(C1):
    def p1_get(self):
        return self._p1 * 100

c1 = C1()
assert c1.p1 == 1
c2 = C2()
assert c1.p1 == 100 ### ERROR

class NiceProperty(object):
    def __init__(self, defvalue=None):
        self.defvalue = defvalue

    def set_name(self, name):
        self.name = name
        self.getter_name = name + '_get'
        self.setter_name = name + '_set'
        self.private_name = '_' + name

    def __get__(self, inst, owner):
        f = getattr(inst, self.getter_name)
        return f()

    def __set__(self, inst, value):
        f = getattr(inst, self.setter_name)
        f(value)

    def create_getter(self):
        vars = dict()
        exec 'def f(x):return x.{}'.format(self.private_name) in vars
        return vars['f']

    def create_setter(self):
        vars = dict()
        exec 'def f(x, y):x.{} = y'.format(self.private_name) in vars
        return vars['f']

class MetaclassNiceProperty(type):
    def __new__(cls, name, bases, dict_):
        d1_ = dict(dict_) # copy dict_
        for k, v in d1_.iteritems():
            if isinstance(v, NiceProperty):
                v.set_name(k)
                if v.getter_name not in d1_:
                    dict_[v.getter_name] = v.create_getter()
                if v.setter_name not in d1_:
                    dict_[v.setter_name] = v.create_setter()
                # create private-attribute for property with default value
                dict_[v.private_name] = v.defvalue
        return type.__new__(cls, name, bases, dict_)

if __name__ == '__main__':
    class Base(object):
        __metaclass__ = MetaclassNiceProperty

    class WithProp(Base):
        prop1 = NiceProperty('s1')
        prop2 = NiceProperty(1)

    class WithProp2(WithProp):
        def prop2_get(self):
            return self._prop2 * 100

    a1 = WithProp2()
    assert a1.prop1 == 's1'
    assert a1.prop2 == 100
    a1.prop2 = 2
    assert a1.prop2 == 200

class C1(object):
    def __init__(self):
        self._p1 = 1

    @property
    def p1(self):
        return self._p1

    @p1.setter
    def p1(self, v):
        self._p1 = v

class C2(C1):

    @property
    def p1(self):
        return self._p1 * 100

    p1 = p1.setter(C1.p1.fset)

c1 = C1()
assert c1.p1 == 1
c1.p1 = 5
assert c1.p1 == 5


c2 = C2()
assert c2.p1 == 100
c2.p1 = 5
assert c2.p1 == 500

class C1(object):
    def __init__(self):
        self._p1 = 1
    @property
    def p1(self):
        return self._p1
    @p1.setter
    def p1(self, v):
        self._p1 = v
    #p1 = (p1_get, p1_set)

class C2(C1):
    @C1.p1.getter
    def p1(self):
        return self._p1 * 100

c1 = C1()
assert c1.p1 == 1
c2 = C2()
assert c2.p1 == 100 ### ERROR