Learn to build a CLI tool that extends TaskWarrior functionality to display a productivity scoreboard using only Python's standard libraries. Explore how to replicate popular data cleansing routines typically performed with pandas and numpy, including group by operations, aggregation, filling missing values in time series, creating tabular summaries, and implementing a command-line interface. Discover how to create efficient utilities without relying on external dependencies, saving significant memory and compilation time. Access the provided code repository, tasklib, and TaskWarrior links to enhance your understanding and implementation of this powerful productivity tool.