O'REILLY
Python Polars The Definitive Guide
Transforming, Analyzing, and Visualizing Data with a Fast and Expressive DataFrame API
Jeroen Janssens & Thijs Nieuwdorp
Foreword by Ritchie Vink, Creator of Polars
I'm currently reading "Python Polars: The Definitive Guide" by Jeroen Jannssens and Thijs Nieuwdorp, and I'm tempted to switch from pandas to polars, especially since @pola.rs is on Bluesky. ๐ #Python #Rust
20.02.2026 20:18
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We also have 's-Hertogenbosch. Yes it starts with an apostrophe.
21.10.2025 20:36
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Posit
Connect with a vibrant global community of R and Python data scientists at Posit's annual conference. Learn, share, and grow your expertise in data science.
I am starting to prep for my #positconf2025 talk this year, and I am excited but also a bit nervous ๐
because I am sharing how TERRIBLE things went for me the first time I tried to learn Python! ๐
Hoping it will be interesting to the Python-curious and beyond:
posit.co/conference/
25.07.2025 16:52
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I just finished recording an amazing #PydyTuesday Uncut episode with @wesmckinney.com.
We look at scraped GitHub data, untangle deeply nested JSON, and create some sort of pulse signal for various popular GitHub repos.
๐ฝ๏ธ Watch the full episode here: lnkd.in/eKtuxAjg
21.07.2025 16:49
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I've recorded another #PydyTuesday Uncut session with @mchow.com. Watch the full episode: www.youtube.com/watch?v=kyVS...
07.07.2025 13:25
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Thanks, Nathan!
27.06.2025 06:31
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Michael, thank you so much! It's great to hear that you like the book and it's much appreciated that you took the time to write such a generous review.
17.06.2025 12:27
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![Python code using Polars and great_tables libraries to create a DataFrame with two columns and apply a blue background style to rows where column 'a' contains null values. The code is followed by an image showing the resulting styled table.
Here is the Python code:
```
import polars as pl
from great_tables import loc, style
(
pl.DataFrame({"a": [1, None], "b": [3, 4]})
.style
.tab_style(
style.fill("aliceblue"),
loc.body(rows=pl.col("a").is_null())
)
)
```](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:7gygvhegj2i2q2ebjqozbkkd/bafkreidkx6xs4gktbtsjp4djso7ztqsgjtrskdugmgxxmwl7qsk6sgh4zm)
Python code using Polars and great_tables libraries to create a DataFrame with two columns and apply a blue background style to rows where column 'a' contains null values. The code is followed by an image showing the resulting styled table.
Here is the Python code:
```
import polars as pl
from great_tables import loc, style
(
pl.DataFrame({"a": [1, None], "b": [3, 4]})
.style
.tab_style(
style.fill("aliceblue"),
loc.body(rows=pl.col("a").is_null())
)
)
```
New post! Great Tables: Becoming the Polars .style property
When you use Polars `DataFrame.style` it returns a Great Tables object. This is a bit cheesy, but I look back on all the pieces the open source community chipped in to make this happen ๐ฅฒ.
posit-dev.github.io/great-tables...
17.04.2025 16:18
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Now that the book is out, we're shifting our focus to spreading the word. Look for us at upcoming conferences, on podcasts, and more. Stay tuned!
02.04.2025 13:21
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We're also incredibly grateful to our technical reviewers, the Polars community, our colleagues from Xomnia and @posit.co, friends, and family; many of whom are listed in the acknowledgements.
02.04.2025 13:21
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We had the pleasure of collaborating with NVIDIA and @delltechnologies.bsky.social to benchmark Polars on the GPU. The results are documented in the appendix. Thank you Mark Cai, Irina Shekhovtsova, and Logan Lawler for making this possible.
02.04.2025 13:21
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Special thanks to Ritchie Vink, the creator of @pola.rs, for answering our countless questions, and for writing such a generous foreword.
02.04.2025 13:21
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A huge thank you to our amazing editors at @oreilly.bsky.social : Aaron Black for believing in this project, Sarah Grey for guiding us through the writing process, and Jonathon Owen for helping us cross the finish line.
02.04.2025 13:21
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Thijs and I have been pouring our hearts into this project for nearly two years, and it's surreal to finally see it on the shelves. Funny story: we don't have our own author copies yet because the book was apparently sold out (hence the picture at our local bookstore)!
02.04.2025 13:21
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While you're on the book website, you can also:
โถ๏ธ Get a sneak peak by downloading a sample chapter
๐ฌ Read what others have to say about the book
๐ปโโ๏ธ Join the community to connect with other readers
โจ๏ธ Explore the GitHub repository, where youโll find all the code and data from the book to follow along
02.04.2025 13:21
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Our book is out! ๐ฅณ
Itโs official: ๐๐ฎ๐ฉ๐๐ค๐ฃ ๐๐ค๐ก๐๐ง๐จ: ๐๐๐ ๐ฟ๐๐๐๐ฃ๐๐ฉ๐๐ซ๐ ๐๐ช๐๐๐ is now available in both ebook and print formats at your favorite bookstore!
๐ Grab your copy now: polarsguide.com
02.04.2025 13:21
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A promotional advert that says "Data Science Hangout, Jeroen Janssens, Senior Developer Relations Engineer at Posit PBC" and includes a photo of Jeroen on a blue background on one side. Jeroen is a white man with brown hair and a blue shirt, smiling.
Today! 12pm ET - This hangout is gonna be great! Jeroen is the author of Data Science at the Command Line and has a new book coming out soon on Polars.
Follow him here: @jeroenjanssens.com
Add today's call to your calendar here: pos.it/dsh
No slides, not a webinar, more like a weekly data AMA!
13.03.2025 15:22
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A huge thank you to @randyzwitch.bsky.social, @mchow.com, and many others behind the scenes for making this incredible opportunity possible. I'm excited to be working alongside such a talented group.
10.02.2025 14:08
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I'll be:
๐ Advocating for Posit's polyglot data science mission
๐ Creating docs, resources, and video's
๐ Contributing to open-source projects within Posit and the broader PyData ecosystem
๐ฌ Connecting with the community and collaborating with developers
๐ค Giving talks and hosting workshops
10.02.2025 14:08
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I'm thrilled to announce that I've joined @posit.co as a Senior Developer Relations Engineer. ๐
Posit is the company behind some of the most popular and impactful tools for data science, including Shiny, Quarto, Positron, Tidyverse, Great Tables, and Plotnine.
10.02.2025 14:08
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