Introduction to packages, modules, or toolboxes

Over the years, researchers or users have generated many packages around different specific tasks for various programming languages. For this book, we treat module or toolbox as a synonym for package. For the analyses in the area of data science, it is very important to use various packages to achieve our goals. There are several advantages in using various packages. First, we don't have to write our code from scratch if we can find some relevant programs contained in certain packages. This would save us a huge amount of time. In other words, we don't have to reinvent the wheel, and this is especially true for developers. Second, packages are usually developed by people who have certain expertise in relevant areas. Because of this, the quality of a package is usually higher than the programs written by a, relatively speaking...