# Polars 1.8.0 — Python Polars 1.8.0

- Product: Polars (https://whatsnew.fyi/product/polars)
- Vendor: Polars
- Date: 2024-09-23
- Version: 1.8.0
- Original notes: https://github.com/pola-rs/polars/releases/tag/py-1.8.0
- Permalink: https://whatsnew.fyi/product/polars/releases/1.8.0

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Support arithmetic between Series with dtype list
- **changed** — Relax schema alignment for parquet file list read
- **changed** — Always preserve sorted flag for .dt.date
- **changed** — Implement single inequality joins for join_where
- **fixed** — DataFrame plot was raising when some extra keywords were passed to encodings
- **fixed** — Respect strictness in list constructor
- **fixed** — Properly broadcast array arithmetic
- **fixed** — Throw error for comparison of unequal length series
- **fixed** — Raise when parquet file has extra columns and no select() was done
- **fixed** — Pass missing user params in write_csv
- **fixed** — Improve join argument checks
- **fixed** — Struct filter by index
- **fixed** — Proper dtype casting for struct embedded categoricals in chunked categoricals
- **fixed** — Remove panic in arr.to_struct
- **fixed** — Allow empty sort by columns
- **fixed** — Broadcast zip_with for structs
- **fixed** — Fixed dropped/shifted rows in parquet scan with streaming=True
- **fixed** — Fix cum_max using exception text of cum_min for invalid dtype
- **fixed** — Fix accidental raise on shape 1

##### ✨ Enhancements

- Support arithmetic between Series with dtype list (#17823)
- Relaxed schema alignment for parquet file list read (#18803)
- Always preserve sorted flag for .dt.date (#18692)
- Enable additional `ruff` lint rule sets (#18721)
- Implement single inequality joins for join\_where (#18727)

##### 🐞 Bug fixes

- DataFrame plot was raising when some extra keywords were passed to encodings (e.g. `x=alt.X(a, axis=alt.Axis(labelAngle=30))`) (#18836)
- Respect strictness in list constructor (#18853)
- Properly broadcast array arithmetic (#18851)
- Throw error for comparison of unequal length series (#18816)
- Raise when parquet file has extra columns and no `select()` was done (#18843)
- Pass missing user params in `write_csv` (#18845)
- Improve `join` argument checks (#18847)
- Struct filter by index (#18778)
- Proper dtype casting for struct embedded categoricals in chunked categoricals (#18815)
- Fixed some error/assertion types (#18811)
- Remove panic in `arr.to_struct` (#18804)
- Allow empty sort by columns (#18774)
- Broadcast zip\_with for structs (#18770)
- Dropped/shifted rows in parquet scan with `streaming=True` (#18766)
- Fix `cum_max` using exception text of `cum_min` for invalid dtype (#18780)
- Fix accidental raise on shape 1 (#18748)

##### 📖 Documentation

- Fix link to issue tracker and code snippet format in GPU docs (#18850)
- Clarify documentation for `schema` in `read_csv` function (#18759)
- Fix literal type mapping example in `lit` docstrings (#18756)
- Refactor `docs` directory hierarchy (#18773)
- Minor improvements to contributing guide (#18777)
- Improve `over` docs, add example with `order_by` (#18796)
- Add documentation for beta gpu support (#18762)

##### 🛠️ Other improvements

- Re-export PyO3 in `polars-python` crate (#18835)
- Make `NodeTraverser` struct public (#18822)
- Add panic to unchecked DataFrame constructors in debug mode (#18807)
- Fix parquet file metadata is dropped after first DSL->IR conversion (#18789)
- Remove extra hashmap construction in new-streaming parquet (#18792)
- Remove TODO comment regarding NumPy pinning (#18776)
- Remove unused methods (#18744)
- Make DataFrame a Vec of `Column` instead of `Series` (#18664)
- Run benchmark on PR labeled 'needs-bench' (#18737)
- Enable additional `ruff` lint rule sets (#18721)

Thank you to all our contributors for making this release possible!
@3ok, @Manishearth, @MarcoGorelli, @adamreeve, @alexander-beedie, @barak1412, @beckernick, @bradfordlynch, @coastalwhite, @deanm0000, @eitsupi, @i64, @itamarst, @mcrumiller, @nameexhaustion, @orlp, @r-brink, @ritchie46, @rodrigogiraoserrao, @squnit, @stinodego and @t-ded