Can you explain the purpose of the __get__() method in Python descriptors and how it is used?

The __get__() method in Python is part of the descriptor protocol. A descriptor is an object that manages access to attributes of another object.

When an object has a descriptor attribute with a __get__() method, this method is called when accessing that attribute.

Method signature:

def __get__(self, instance, owner):
    ...

• self — the descriptor itself
• instance — the object requesting the attribute (or None if accessed through the class)
• owner — the class to which the object belongs

Example usage:

class Descriptor:
    def __get__(self, instance, owner):
        print(f'__get__ called for {instance} of class {owner}')
        return 42

class MyClass:
    attr = Descriptor()

obj = MyClass()
print(obj.attr)  # Accessing attr calls Descriptor.__get__

Output:

__get__ called for <__main__.MyClass object at 0x...> of class <class '__main__.MyClass'>
42

Thus, __get__() allows controlling what is returned when accessing an attribute, enabling properties, computed values, lazy loading, and other patterns.