What are metaclasses in Python?

In Python, a metaclass is a class that defines the behavior of a class. When you create a class, Python automatically creates a metaclass for you behind the scenes. You can think of a metaclass as a blueprint for creating a class.

Metaclasses are a advanced concept in Python and are not often used in everyday programming. They are used to modify the behavior of a class, as well as the behavior of objects created from that class.

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Here is an example of how you might use a metaclass to create a class:

class MyMetaclass(type):
    def __new__(cls, name, bases, attrs):
        # Modify the class here
        return super().__new__(cls, name, bases, attrs)

class MyClass(metaclass=MyMetaclass):
    pass

In this example, MyMetaclass is a metaclass that is used to create the MyClass class. When you create an instance of MyClass, it will be created using the behavior defined in MyMetaclass.

Metaclasses can be used to modify the behavior of a class in a variety of ways. For example, you might use a metaclass to automatically add certain attributes to a class, or to modify the way that the class behaves when it is called.