A very important feature of the functional programming paradigm is higher-order functions. These are functions that accept functions as arguments or return functions as results. Python offers several of these kinds of functions. We'll look at them and some logical extensions.
As we can see, there are three varieties of higher-order functions, which are as follows:
Functions that accept a function as one of its arguments
Functions that return a function
Functions that accept a function and return a function
Python offers several higher-order functions of the first variety. We'll look at these built-in higher-order functions in this chapter. We'll look at a few of the library modules that offer higher-order functions in later chapters.
The idea of a function that emits functions can seem a bit odd. However, when we look at a Callable class object, we see a function that returns a Callable object. This is one example of a function that creates another function.
Functions...