What are Python decorators?

Python decorators are indeed functions that modify the behavior of another function. They allow you to wrap another function in order to extend its behavior without permanently modifying it. This is useful for a variety of scenarios, such as logging, enforcing access control, instrumentation, and caching. The syntax for decorators typically uses the @decorator_name syntax preceding the function definition, which applies the decorator to that function.

When using a decorator, you define a function that takes another function as an argument, wraps it in additional functionality, and then returns the modified function. This enhances the original function's capabilities while keeping the original implementation intact.

This concept harnesses the power of higher-order functions in Python, where functions can be passed around like any other object. In essence, decorators provide a clean and readable way to implement cross-cutting concerns in your code, promoting reusability and separation of concerns.

The other choices do not encapsulate the functionality of decorators accurately. Classes pertain to object-oriented programming, which involves creating objects and methods, while variables typically refer to storage locations for data within the program and do not inherently extend functionality. Modules can provide additional functionality but are more about organizing code into separate files rather than modifying functions directly.