Python offers us many ways to create higher-order functions. In Chapter 5, Higher-Order Functions, we looked at two techniques: defining a function that accepts a function as an argument, and defining a subclass of Callable, which is either initialized with a function or called with a function as an argument.

One of the benefits of decorated functions is that we can create composite functions. These are single functions that embody functionality from several sources. A composite function, , can be somewhat more expressive of a complex algorithm than . It's often helpful to have a number of syntax alternatives for expressing complex processing.

In this chapter, we'll look at the following topics:

• Using a decorator to build a function based on another function
• The wraps() function in the functools module; this can help us build decorators
• The update_wrapper() function, which may be helpful