As a first step toward more sophisticated simulation programming, this chapter presents a Python simulation of the TTF example in Chap. 1. It also provides a gentle introduction to some important simulation concepts, and a brief overview of Python, leaving the details to Chap. 4. All readers should go through this chapter, even if they will not ultimately program their simulations in Python. The focus here is on basic discrete-event simulation programming principles without using any special simulation support functions or objects. These principles form the core ideas for more sophisticated and scalable programming.