@Property example

exp_property.py

#!/usr/bin/env python3
# -*- coding:utf8 -*-
from __future__ import print_function
from copy import deepcopy

class MyAwesomObject(object):
    def __init__(self, private_value):
        self.__private_value = private_value
    
    @property
    def private_value(self):
        return deepcopy(self.__private_value)
    
    @private_value.setter
    def private_value(self, new_value):
        raise RuntimeError("Public access to private value is not allowed")
        # you can also do type checking here and update private value 
        # instead of raising RuntimError

if __name__ == "__main__":
    my_obj = MyAwesomObject([1, 2, 3])
    ori_list = my_obj.private_value
    ori_list[0] = 10
    print(ori_list)
    print(my_obj.private_value)
    try:
        my_obj.private_value = 3
    except RuntimeError as e:
        print("Can not assign value to private variable :)")