Data-science investigations have brought journalism into the 21st century, and—guided by The Intercept’s infosec expert Micah Lee— this book is your blueprint for uncovering hidden secrets in hacked datasets. In the current age of hacking and whistleblowing, the internet contains massive troves of leaked information. These complex datasets can be goldmines of revelations in the public interest— if you know how to access and analyze them. For investigative journalists, hacktivists, and amateur researchers alike, this book provides the technical expertise needed to find and transform unintelligible files into groundbreaking reports. Using Python or other programming languages, you can give your computer precise instructions for performing tasks that existing tools or shell scripts don’t allow. For example, you could write a Python script that scours a million pieces of video metadata to determine where the videos were filmed. In my experience, Python is also simpler, easier to understand, and less error-prone than shell scripts. This chapter provides a crash course on the fundamentals of Python programming. You’ll learn to write and execute Python scripts and use the interactive Python interpreter. You’ll also use Python to do math, define variables, work with strings and Boolean logic, loop through lists of items, and use functions.