This chapter concludes this part of the book with a collection of more advanced module-related topics—data hiding, the __future__ module, the __name__ variable, sys.path changes, listing tools, running modules by name string, transitive reloads, and so on—along with the standard set of gotchas and exercises related to what we’ve covered in this part of the book.

Along the way, we’ll build some larger and more useful tools than we have so far, that combine functions and modules. Like functions, modules are more effective when their interfaces are well defined, so this chapter also briefly reviews module design concepts, some of which we have explored in prior chapters.