Learn how to create a weekly rolling sum using only Python's standard library, without relying on pandas. This 29-minute tutorial demonstrates the power of Python's core libraries for data manipulation and reshaping. Discover how to leverage itertools' groupby, enumerate, and isocalendar functions to achieve a weekly rolling sum. Follow along as the instructor builds upon previous episodes in the series, showcasing the development of a task management tool called TaskQuant. Gain insights into creating a command-line productivity scoreboard for TaskWarrior, implementing colorful terminal CLI interfaces, and structuring a production-ready Python package. By the end of the tutorial, you'll be able to use the `taskquant` package to generate task scoreboards and weekly rolling sums directly from the command line.