Metaclasses can be used to implement custom class creation behavior. For example, you can use a metaclass to automatically add certain attributes or methods to all classes that are created with that metaclass. This can be useful for enforcing coding standards, implementing declarative programming, or even adding additional functionality to classes at runtime.

One practical use case of metaclasses is in the Django framework, where they are used extensively. In Django, metaclasses are used to create Model classes, which are the building blocks of database tables. Metaclasses are responsible for automatically generating the necessary fields and methods based on the defined Model class. This allows developers to define their models in a concise and expressive way without having to manually write repetitive code.

Metaclasses can also be used for implementing advanced debugging or profiling techniques. By using a metaclass, you can automatically wrap all methods of a class with additional code for logging, timing, or tracing purposes. This can be especially useful when working on large projects where you want to collect detailed runtime information without modifying each individual method manually.

Overall, metaclasses provide a powerful and flexible way to customize class creation behavior in Python, and their practical applications extend beyond just the examples mentioned here.