Python property () function

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Function property() used to define properties in classes.

Method property() provides an interface for the attributes of an instance of a class. It encapsulates instance attributes and provides properties, similar to how it works in Java and C #.

Method property() accepts methods as input get, set and delete, and returns objects of the class property…

Instead of a method property() it’s better to use a decorator property (https://www.tutorialsteacher.com/python/property-decorator).

Parameters:

1. fget: (optional) Function to get the value of an attribute. The default is None.

2. fset: (optional) Function for setting the attribute value. The default is None.

3. fdel: (optional) Function to remove the attribute value. The default is None.

4. doc: (optional) A string containing the documentation. The default is None.

Returning values:

Returns the property attribute from the specified getter, setter, and delete function.

The following example shows how to create a property in Python using the function property()…

class person:
    def __init__(self):
        self.__name=""
    def setname(self, name):
        print('setname() called')
        self.__name=name
    def getname(self):
        print('getname() called')
        return self.__name
    name=property(getname, setname)

In the example above property(getname, setname) returns a property object and gives it a name. Thus, the property name hides a private instance __name… Property access name carried out directly, but inside the method is called getname() or setname(), as shown below.

>>> from person import person
>>> p1=person()
>>> p1.name="Steve"
setname() called
>>> p1.name
getname() called
'Steve'

As seen above, the method getname() called automatically when we access the property name… Similarly, the method setname called when we assign a value to a property name… It hides the class attribute __name…

Similarly, you can write a method for removing a property, as in the code below.

class person:
    def __init__(self, name):
        self.__name=name
    def setname(self, name):
        print('setname() called')
        self.__name=name
    def getname(self):
        print('getname() called')
        return self.__name
    def delname(self):
        print('delname() called')
        del self.__name
    # Set property to use get_name, set_name
    # and del_name methods
    name=property(getname, setname, delname)

Function delname() will be called when you remove the property name…

>>> from person import person
>>> p1=person()
>>> p1.name="Steve"
setname() called
>>> del p1.name
delname() called

Thus, we can define a property in a class using the function property() in Python.

Decorator @property simplifies property declaration and allows you to do it without calling a function property()…

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