Hacker News: jeroenjanssens

New comment by jeroenjanssens in "Python Polars Cheatsheet (based on our O'Reilly book)"

jeroenjanssens — Tue, 18 Aug 2026 16:06:46 +0000

Yes, opensource.posit.co is entirely open source :)

https://github.com/posit-dev/open-source-website/blob/main/c...

New comment by jeroenjanssens in "Python Polars Cheatsheet (based on our O'Reilly book)"

jeroenjanssens — Tue, 18 Aug 2026 13:38:23 +0000

We spent the last few weeks compressing our book, Python Polars: The Definitive Guide (nearly 500 pages), down to a two-page cheatsheet. It's a highly lossy compression, but hopefully a useful one! Besides the PDF, there's also an accessible HTML version.

We're curious to hear what you think. Let us know if we missed any of your favorite Polars operations, or if you have any feedback on how we organized it.

Python Polars Cheatsheet (based on our O'Reilly book)

jeroenjanssens — Tue, 18 Aug 2026 13:38:23 +0000

Article URL: https://opensource.posit.co/resources/cheatsheets/polars/

Comments URL: https://news.ycombinator.com/item?id=49345476

Points: 182

# Comments: 40

Translating Pandas to Polars using LLMs

jeroenjanssens — Fri, 26 Jun 2026 08:39:03 +0000

Article URL: https://pola.rs/posts/llm-polars-patterns/

Comments URL: https://news.ycombinator.com/item?id=48684034

Points: 9

# Comments: 0

New comment by jeroenjanssens in "Plotnine"

jeroenjanssens — Tue, 23 Jun 2026 09:18:45 +0000

While it’s generally considered to be bad practice to import everything into the global namespace, I think it’s fine to do this in an ad-hoc environment such as a notebook as it makes using the many functions plotnine provides more convenient. An additional advantage is that the resulting code more closely resembles the original ggplot2 code. Alternatively, it’s quite common to `import plotnine as p9` and prefix every function with `p9`.

Disclaimer: I made the plotnine homepage and cheatsheet.

Show HN: Plotnine Cheatsheet [pdf]

jeroenjanssens — Tue, 14 Oct 2025 11:57:33 +0000

I wanted to share with you a cheatsheet I made for Plotnine, a data visualization package for Python.

I've probably never spent so much time on just two pages, even with the ggplot2 cheatsheet as a starting point. Hope you find it useful.

Comments URL: https://news.ycombinator.com/item?id=45578960

Points: 1

# Comments: 0

Ditching Poetry for Uv

jeroenjanssens — Tue, 28 Jan 2025 11:33:35 +0000

Article URL: https://thijsnieuwdorp.com/posts/uv/

Comments URL: https://news.ycombinator.com/item?id=42851235

Points: 2

# Comments: 0

New comment by jeroenjanssens in "Ask HN: Best way to learn robotics with a 10 year old?"

jeroenjanssens — Fri, 26 Jul 2024 15:17:43 +0000

You can probably get these sets second hand. I just revived a bricked one (hah!) myself. Had to use the Lego software to update the firmware for that, which only runs on Windows 7, 8, and 10.

I just got NXT-Python [1] working on macOS via a USB cable. No luck pairing the brick to my MacBook via Bluetooth yet. Nevertheless, I can't wait to get building robots with my kids!

[1] https://ni.srht.site/nxt-python/latest/handbook/overview.htm...

New comment by jeroenjanssens in "ht: Headless Terminal"

jeroenjanssens — Tue, 04 Jun 2024 17:49:51 +0000

I've created tmuxr, an R package to manage tmux [0].

[0] https://github.com/jeroenjanssens/tmuxr

New comment by jeroenjanssens in "Data Science at the Command Line, 2nd Edition (2021)"

jeroenjanssens — Mon, 06 May 2024 13:01:09 +0000

Author here.

Worth pointing out that the discussion from Sept 19 2013 is actually about a blog post, which predates the book. It's because of the amount of feedback it got on HN that I wondered whether this topic could be turned into a book.

Coincidentally, tomorrow I'll be speaking at the New York Open Statistical Programming Meetup [0]. About 11 years ago, I spoke there for the first time. That talk is the reason the aforementioned blog post (and by extension the book) exists.

In short, I owe a lot to that meetup and the HN community. Thanks!

[0] https://nyhackr.org/

New comment by jeroenjanssens in "Python Chart Examples"

jeroenjanssens — Tue, 16 Apr 2024 12:57:53 +0000

I also thought it was made with TikZ (which is a compliment). I used TikZ for my thesis: https://jeroenjanssens.com/phd/ and same thing here, the code is a mess.

LiteJQ: Jq Support in SQLite

jeroenjanssens — Fri, 23 Feb 2024 04:11:25 +0000

Article URL: https://github.com/Florents-Tselai/liteJQ

Comments URL: https://news.ycombinator.com/item?id=39476876

Points: 11

# Comments: 2

New comment by jeroenjanssens in "Polars"

jeroenjanssens — Tue, 09 Jan 2024 09:39:02 +0000

Luckily our book will also be available in hard copy so you can digest all that hard-won knowledge in an offline manner :)

New comment by jeroenjanssens in "Polars"

jeroenjanssens — Tue, 09 Jan 2024 08:09:16 +0000

Ritchie Vink (the creator of Polars) deliberately decided not to write a book so that he (and his team) can focus full time on Polars itself.

Thijs Nieuwdorp and I are currently working on the O'Reilly book "Python Polars: The Definitive Guide" [1]. It'll be a while before it gets released, but the Early Release version on the O'Reilly platform gets updated regularly. We also post draft chapters on the Polars Discord server [2].

The Discord server is also a great place to ask questions and interact with the Polars team.

[1] More information about the book: https://jeroenjanssens.com/pp/

[2] Polars Discord server: https://discord.gg/fngBqDry

New comment by jeroenjanssens in "Polars: Company Formation Announcement"

jeroenjanssens — Thu, 03 Aug 2023 17:56:16 +0000

Thanks! Our goal is to have it published in Q3 2024.

New comment by jeroenjanssens in "Polars: Company Formation Announcement"

jeroenjanssens — Thu, 03 Aug 2023 17:35:47 +0000

This is great news. Makes me proud to be a co-author of the forthcoming Polars book [0]. Congrats to Ritchie, Chiel, and the rest of the team!

[0]: https://jeroenjanssens.com/pp

Scripting iTerm Key Mappings

jeroenjanssens — Thu, 19 Jan 2023 20:05:43 +0000

Article URL: https://jeroenjanssens.com/itermkeymap/

Comments URL: https://news.ycombinator.com/item?id=34444919

Points: 1

# Comments: 0

New comment by jeroenjanssens in "The Linux Command Line"

jeroenjanssens — Thu, 29 Dec 2022 18:21:35 +0000

Related: Data Science at the Command Line

https://datascienceatthecommandline.com/

Disclaimer: I wrote it. Plugging it here because (a) it's related, (b) it's free to read online, and (c) would not have existed without HN.

Raylibr is an R package that wraps Raylib for videogames programming

jeroenjanssens — Thu, 20 Oct 2022 13:39:43 +0000

Article URL: https://github.com/jeroenjanssens/raylibr

Comments URL: https://news.ycombinator.com/item?id=33274550

Points: 2

# Comments: 0

New comment by jeroenjanssens in "Bash one-liner to produce a list of HEX color codes that read like English words"

jeroenjanssens — Sun, 02 Oct 2022 06:11:25 +0000

My book Data Science at the Command Line has a chapter about this that scratches the surface and lists some resources in case you want to dive deeper [1]. I can also recommend checking out packages such as Rich [2] and Click [3], if only to get an idea of the possibilities when it comes to creating command-line tools with Python.

[1] https://datascienceatthecommandline.com/2e/chapter-4-creatin...

[2] https://github.com/Textualize/rich

[3] https://click.palletsprojects.com/en/8.1.x/