To tap into the power of Python's open data science stack--including NumPy, Pandas, Matplotlib, Scikit-Learn, and other tools--you first need to understand the syntax, semantics, and patterns of the Python language. This report provides a brief yet comprehensive introduction to Python for engineers, researchers, and data scientists who are already familiar with another programming language. Author Jake VanderPlas, an interdisciplinary research director at the University of Washington, explains Python's essential syntax and semantics, built-in data types and structures, function definitions, control flow statements, and more, using Python 3 syntax.