Python Polars: The Definitive Guide: Transforming, Analyzing, and Visualizing Data with a Fast and Expressive DataFrame API

by Jeroen Janssens, Thijs Nieuwdorp

Overview

Unlock the power of Polars, a Python package for transforming, analyzing, and visualizing data. In this hands-on guide, Jeroen Janssens and Thijs Nieuwdorp walk you through every feature of Polars, showing you how to use it for real-world tasks like data wrangling, exploratory data analysis, building pipelines, and more.

Whether you're a seasoned data professional or new to data science, you'll quickly master Polars' expressive API and its underlying concepts. You don't need to have experience with pandas, but if you do, this book will help you make a seamless transition. The many practical examples and real-world datasets are available on GitHub, so you can easily follow along.

• Process data from CSV, Parquet, spreadsheets, databases, and the cloud
• Get a solid understanding of Expressions, the building blocks of every query
• Handle complex data types, including text, time, and nested structures
• Use both eager and lazy APIs, and know when to use each
• Visualize your data with Altair, hvPlot, plotnine, and Great Tables
• Extend Polars with your own Python functions and Rust plugins
• Leverage GPU acceleration to boost performance even further

Product Details

ISBN-13:	9781098156084
Publisher:	O'Reilly Media, Incorporated
Publication date:	04/01/2025
Pages:	400
Product dimensions:	7.00(w) x 9.19(h) x 0.00(d)

About the Author

Jeroen Janssens is a Senior Machine Learning Engineer at Xomnia in Amsterdam, where he uses Polars on a daily basis. He enjoys wrangling data, implementing machine learning models, and building solutions using Python, R, JavaScript, and Bash. Previously, he ran Data Science Workshops, a training and coaching firm. Jeroen is the author of Data Science at the Command Line (O'Reilly, 2021). He has been an assistant professor at Jheronimus Academy of Data Science and a data scientist at various startups in New York City. Jeroen holds a PhD in machine learning from Tilburg Universityand an MSc in artificial intelligence from Maastricht University. He lives with his wife and two kids in Rotterdam, the Netherlands.

Thijs Nieuwdorp is the Lead Data Scientist at Xomnia in Amsterdam. His interest in the interaction between human and computer led him to an education in Artificial Intelligence at the Radboud University, after which he dove straight into the field of Data Science. At Xomnia he witnessed the birth of Polars as Ritchie Vink started working on it during his employment there , and has been using it in his projects ever since. He enjoys figuring out complex data problems, optimizing existing solutions, and putting them to good use by implementing them into business processes. Outside work Thijs enjoys exploring our world through hiking and traveling, and exploring other worlds through books, games, and movies. He lives in Amsterdam with his partner.