# Polars 1.2.1 — Python Polars 1.2.1

- Product: Polars (https://whatsnew.fyi/product/polars)
- Vendor: Polars
- Date: 2024-07-18
- Version: 1.2.1
- Original notes: https://github.com/pola-rs/polars/releases/tag/py-1.2.1
- Permalink: https://whatsnew.fyi/product/polars/releases/1.2.1

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'.

---

- **changed** — Specify tune-cpu and add more features for performance optimization
- **changed** — Improve garbage collection and push_view for binviews
- **changed** — Raise error instead of panic in unsupported serde
- **added** — Expose Arrow C interface directly on Polars
- **added** — Include file path option for NDJSON
- **fixed** — Use bytemuck in slice reinterpret for Parquet ArrayChunks
- **fixed** — Remove non-existing names from __all__
- **fixed** — Fix return type hint for LazyFrame sink methods
- **fixed** — Propagate struct outer nullability eagerly
- **fixed** — Address read_database issue with batched reads from Snowflake
- **fixed** — Use ETag for HTTP file cache invalidation
- **fixed** — Fix default name for value_counts methods based on normalize parameter
- **added** — Add reduce ComputeNode in new streaming engine

##### 🚀 Performance improvements

- Specify tune-cpu \& add more features (#17615)
- Better GC and push\_view for binviews (#17627)

##### ✨ Enhancements

- Raise error instead of panic in unsupported serde (#17679)
- Expose Arrow C interface directly on Polars (#17696)
- Include file path option for NDJSON (#17681)

##### 🐞 Bug fixes

- Use bytemuck in slice reinterpret for Parquet ArrayChunks (#17700)
- Remove non-existing names from `__all__` (#17494)
- Fix return type hint for LazyFrame `sink` methods (#17698)
- Propagate struct outer nullability eagerly (#17697)
- Address `read_database` issue with batched reads from Snowflake (#17688)
- Use ETag for HTTP file cache invalidation (#17684)

##### 📖 Documentation

- Fixed default name for `value_counts` methods based on normalize parameter (#17685)

##### 📦 Build system

- Pin `setuptools` to fix failing CI (#17695)

##### 🛠️ Other improvements

- Fix return type hint for LazyFrame `sink` methods (#17698)
- Pin `setuptools` to fix failing CI (#17695)
- Name tests so they actually run (#17690)
- Add reduce `ComputeNode` in new streaming engine (#17389)

Thank you to all our contributors for making this release possible!
@5j9, @ByteNybbler, @MarcoGorelli, @alexander-beedie, @coastalwhite, @diegoglozano, @eitsupi, @nameexhaustion, @orlp, @ragyabraham, @ritchie46 and @ruihe774