property()

The property() function in Python creates and returns a property object. Properties are special attributes that allow the user to define getter, setter, and deleter methods for a class attribute. This function is typically used as a decorator to define properties in a more readable and concise way.

Parameter Values

Parameter Description
fget

Function to retrieve the attribute value
fset

Function to set the attribute value
fdel

Function to delete the attribute value
doc

Docstring for the attribute

Return Values

The property() function returns a property object that can encapsulate getter, setter, and deleter methods.

How to Use property() in Python

Example 1:

The property() function returns a property attribute for a new-style class. It takes four optional parameters: fget, fset, fdel, and doc.

class Celsius:
    def __init__(self, temperature=0):
        self._temperature = temperature
    def get_temperature(self):
        return self._temperature
    def set_temperature(self, value):
        if value < -273.15:
            raise ValueError('Temperature below -273.15 is not possible')
        self._temperature = value
    temperature = property(get_temperature, set_temperature)
Example 2:

The property() function can also be used as a decorator. In this case, the getter method returns the value directly, and there is no setter method defined.

class Circle:
    def __init__(self, radius):
        self._radius = radius
    @property
    def area(self):
        return 3.14 * self._radius**2
Example 3:

The property() function can be used with only a getter method to create a read-only attribute.

class Person:
    def __init__(self, name):
        self._name = name
    @property
    def name(self):
        return self._name

Built-In Functions