This course is an introductory course on data analytics and its applications in smart energy systems. It covers three major topics: 1) Data analytics theory including classification, regression, principal component analysis, and visualization etc.; 2) Python coding with NumPy, Matplotlib, Pandas, & Scikit-learn packages; and 3) Applications in smart energy systems (with a focus on buildings), in which comprehensive experiments with real building energy data will be included. In this course, students will learn systematic knowledge on data analytics and Python. They will also gain solid hands-on experiences in using Python to analyze smart meter data in energy systems of smart buildings.