The sequencing of the human genome at the start of this century fueled a computational revolution in biology. As a result, modern biology produces as many new algorithms as any other fundamental realm of science.Once we have sequenced a genome, it may look like an incomprehensible string of the nucleotides A, C, G, and T. Yet hidden in these four letters is a secret language. In this course, we will start understanding this language by using computer programming. What makes this course distinct is that we assume that you have never programmed before.While learning Python from the ground up, we will write algorithms to determine where a bacterium starts replicating its genome, a problem with applications in genetic engineering. We will also use programming to learn how a cell knows what time of day it is and how the bacterium causing tuberculosis can hide from antibiotics.This course offers a much gentler-paced alternative to Finding Hidden Messages in DNA, the first course in the Bioinformatics Specialization. After completing it, we hope you will be well prepared to jump into the full Specialization!