Polars

Raised as a usability problem by 9 people on Hacker News over 5 years (2022–2026), in 6 threads.

People raised many different problems with Polars, but no single problem has yet been raised by 3 people in 3 different months and threads.

Unreviewed issues were grouped by machine: Claude Haiku labelled each comment as a usability complaint, named what it's about and summed up the problem in a line, and a small model grouped similar problems. Nobody has checked them by hand. Expect mistakes.

The newest 10 complaints

Can't easily mix static text with multiple columns when building new string columns2026-10-06
Its syntax is hard to read, making even SQL look clear by comparison2026-09-03
Must write pl.col("name") instead of df.name, making quick interactive work harder2025-03-08
Expressions are clunky for basic computation, requiring pl.col and pl.literal wrappers2025-03-07
Non-trivial group-by operations with expressions become painful to write2024-11-16
API is very verbose, harder to write than it should be2024-01-09
Steep learning curve due to subtle breaking changes and confusing docs2024-01-09
Feels like calling an API rather than manipulating data, and is verbose2024-01-09
Docs lack examples for each method, so the user must hunt for syntax2022-05-01
Documentation feels bare, so finding functions and examples is hard compared to pandas2022-05-01