At the beginning of a project, you’re likely eager to get started and accomplish something tangible. This is understandable—building things and solving problems can be rewarding. But it’s valuable to move slowly at first so you can move quickly later and longer as a project matures. When you’re exploring a new technology or process, it can also be helpful to practice with it first so you can use it deftly. A bit of planning up front can go a long way toward your productivity and resulting morale. In this chapter, you’ll use asdf and venv to create a development environment for the package you’ll work on for the rest of this book.