Error using Decorator in a Setter method

Question

I’m trying to implement a simple Python code to practice using decorators in conjunction with advisory methods (Getters and Setters), but I’m getting an error.

The code is as follows::

class Pessoa():
    def __init__(self, anos):
        self._idade = 0 
        self.idade = anos

    @idade.setter
    def idade(self, anos):
        self._idade = anos

alguem = Pessoa(18)

And the error that is occurring is as follows:

NameError: name 'idade' is not defined

I do not understand, because 'age' does exist!

I searched on the internet for examples of use of decorators in conjunction with advisory methods and found some codes, but could not figure out where I am missing.

There is a way to implement only the Setter method with decorators?

Answer 1

When assigning an _ or __ (private and protected) you should treat the attributes using a getter before passing it through the Setter. This assignment is performed through @Property, followed by the method that returns the properly treated attribute.

Other important aspects:

1. do not start two variables of the same name, differentiated only by the private and protected attribute (it is not in any way a good practice).
2. When assigning a class you should not assign (), this is an initiator task that you set below. The correct way to define the class is only "class Name:"

Your code would be corrected as follows:

class Pessoa:
    def __init__(self, anos):
        self._idade = anos

    @property
    def idade(self):
        return self._idade

    @idade.setter
    def idade(self, anos):
        self._idade = anos

someone = Person(18)