# Polars 1.14.0 — Python Polars 1.14.0

- Product: Polars (https://whatsnew.fyi/product/polars)
- Vendor: Polars
- Date: 2024-11-17
- Version: 1.14.0
- Original notes: https://github.com/pola-rs/polars/releases/tag/py-1.14.0
- Permalink: https://whatsnew.fyi/product/polars/releases/1.14.0

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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- **changed** — Increase default async thread count for low core count systems
- **changed** — Move row group decode off async thread for local streaming parquet scan
- **changed** — Support use of Duration in to_string with ergonomic and performance improvements and tz-aware Datetime bugfix
- **added** — Raise informative error on Unknown unnest
- **added** — Support DataFrame init from raw SQLAlchemy rows
- **added** — Add an is_literal method to expression meta namespace
- **changed** — A different approach to warning users of fork() issues with Polars
- **fixed** — Fix read_database(...,iter_batches=True) type annotations
- **fixed** — Validate subnodes in validate IR
- **fixed** — Raise if merge non-global categoricals in unpivot
- **fixed** — Type hints for window_size incorrectly included timedelta in some rolling functions
- **fixed** — Don't panic if column not found
- **fixed** — Fix gather of Scalar null + idx w/ validity
- **fixed** — Replace _kwargs in collect method
- **fixed** — Fix object chunked gather
- **fixed** — Fix filter scalar nulls
- **fixed** — Replace spaces with   to support showing multiple spaces in HTML repr
- **fixed** — Fix Altair tooltip incorrectly applied to plots which did not accept it
- **fixed** — Respect schema_overrides in batched csv reader
- **fixed** — Fix scanning google cloud with service account credentials file
- **fixed** — Release the GIL in Python APIs, part 2 of 2

##### 🚀 Performance improvements

- Increase default async thread count for low core count systems (#19829)
- Move row group decode off async thread for local streaming parquet scan (#19828)
- Support use of Duration in `to_string`, ergonomic/perf improvement, tz-aware Datetime bugfix (#19697)

##### ✨ Enhancements

- Raise informative error on Unknown unnest (#19830)
- Support DataFrame init from raw SQLAlchemy rows (#19820)
- Support use of Duration in `to_string`, ergonomic/perf improvement, tz-aware Datetime bugfix (#19697)
- Add an `is_literal` method to expression `meta` namespace (#19773)
- A different approach to warning users of fork() issues with Polars (#19197)

##### 🐞 Bug fixes

- Fix `read_database(…,iter_batches=True)` type annotations (#19832)
- Validate subnodes in validate IR (#19831)
- Raise if merge non-global categoricals in unpivot (#19826)
- Type hints for window\_size incorrectly included timedelta in some rolling functions (#19827)
- Don't panic if column not found (#19824)
- Fix gather of Scalar null + idx w/ validity (#19823)
- Replace \_kwargs in collect method (#19618)
- Fix object chunked gather (#19811)
- Fix filter scalar nulls (#19786)
- Replace spaces with \  to support showing multiple spaces in HTML repr (#19783)
- Altair tooltip was being incorrectly applied to plots which did not accept it (#19789)
- Respect schema\_overrides in batched csv reader (#19755)
- Fix scanning google cloud with service account credentials file (#19782)
- Release the GIL in Python APIs, part 2 of 2 (#19762)
- Fix incorrect filter after right-join on LazyFrame (#19775)
- Fix incorrect lazy schema for explode on array columns (#19776)
- Fixed typo in file lazy.py (#19769)

##### 📖 Documentation

- Update bokeh to use cdn to avoid Bokeh Error (#19788)
- Change dprint config (#19747)
- Mention `row_by_keys` in the `to_dict` documentation (#19767)
- Fix link to Graphviz download (#19791)

##### 🛠️ Other improvements

- Add ToField context for common args (#19833)
- Use polars parquet reader for delta scan (#19103)
- Migrate polars-expr AggregationContext to use `Column` (#19736)

Thank you to all our contributors for making this release possible!
@MarcoGorelli, @TNieuwdorp, @YichiZhang0613, @alexander-beedie, @braaannigan, @coastalwhite, @engylemure, @gab23r, @iliya-malecki, @ion-elgreco, @itamarst, @jackxxu, @nameexhaustion, @orlp, @ritchie46, @rodrigogiraoserrao and @sn0rkmaiden