How to Use Properties in Python

Python provides a more elegant and concise way to define getters and setters using the property function.

This function allows you to define a property that is used like an attribute, but with the ability to control its access and modification.

Property Definition

The reserved word property is used to define a property. An optional getter, setter, and deleter can be passed to this function.

class Persona:
    def __init__(self, nombre, edad):
        self._nombre = nombre
        self._edad = edad

    @property
    def nombre(self):
        return self._nombre

    @nombre.setter
    def nombre(self, nombre):
        if isinstance(nombre, str):
            self._nombre = nombre
        else:
            raise ValueError("The name must be a string")
    
    @property
    def edad(self):
        return self._edad

    @edad.setter
    def edad(self, edad):
        if isinstance(edad, int) and edad > 0:
            self._edad = edad
        else:
            raise ValueError("The age must be a positive integer")

Using Properties

With the properties defined, values can be retrieved and set using attribute syntax, making the code cleaner and more readable.

persona = Persona("Luis", 25)
print(persona.nombre)  # Output: Luis
persona.nombre = "Carlos"
print(persona.nombre)  # Output: Carlos

print(persona.edad)  # Output: 25
persona.edad = 30
print(persona.edad)  # Output: 30

Notice that I don’t have to invoke a setter or getter method. I simply get the value with ., and set it with =, just like it were an attribute.