coding utf-8 import sys inspect class Immutable object def __setattr__

# -*- coding: utf-8 -*-

import sys, inspect

class Immutable(object):

    def __setattr__(self, name, value):
        if name in self.__dict__:
            divired = inspect.currentframe(1).f_locals.get('self')

            if not (divired and issubclass(type(divired), Immutable) ):
                raise TypeError("Can't rebind immutable object(%s)" % name)

        super(Immutable, self).__setattr__(name, value)


    def __delattr__(self, name):
        if name in self.__dict__:
            divired = inspect.currentframe(1).f_locals.get('self')

            if divired and issubclass(type(divired), Immutable):
                super(Immutable, self).__delattr__(name)
            else:
                raise TypeError("Can't unbind immutable object(%s)" % name)
        else:
            raise NameError(name)


def test():
    from user_modules.util import Inspectable
    class T(Immutable, Inspectable):

        def __init__(self):
            self.f=10
            self.z=2
            
        def m(self):
            self.f = 1

    t=T()
    print t
    t.m()
    print t
    try:
        t.z=10
    except TypeError:
        pass
    else:
        raise AssertionError

    print t.z

    
if __name__ == "__main__":
    test()