There may be a good definition of metaprogramming from some academy paper that could be cited here, but this is rather a book about good software craftsmanship than about computer science theory. This is why we will use a simple one:
"Metaprogramming is a technique of writing computer programs that can treat themselves as data, so you can introspect, generate, and/or modify itself while running."
Using this definition, we can distinguish two major approaches to metaprogramming in Python.
The first approach concentrates on the language's ability to introspect its basic elements such as functions, classes, or types and to create or modify them on the fly. Python gives a lot of tools to developers in this area. The easiest ones are decorators that allow to add additional functionality to the existing functions, methods, or classes. Next are special methods of classes that allow you to interfere with class instance process creation. The most powerful are metaclasses that allow programmers...