python class with an attribute that no longer exists...

property_setter.py

class Nonsense(object):
    def __init__(self, n):
        self.a = ['x'] * n

    @property
    def length(self):
        return len(self.a)

    @length.setter
    def length(self, n):
        self.a = ['x'] * n

    def __str__(self):
        return "|".join(self.a)


x = Nonsense(5)

print x
print x.length

x.length = 8

print x
print x.length