Python is a free, text-based programming language that has already been used by those who do physics research to great effect. But students can also learn to use it and, through its use, learn other aspects of physics--especially ones that are difficult or impossible to perform as physical labs. This article serves as a most-fundamental start for teachers who are interested in how they can use Python to enhance their physics instruction. Although there have been a few articles that have made references to using Python, none so far in this journal has described how quickly and effectively it can be used to simulate a virtual lab experience or aid in creative design. In this first of two articles, I introduce Python (and VPython) and provide some sample codes to guide beginners.