# Polars 1.43.2 — Python Polars 1.43.2

- Product: Polars (https://whatsnew.fyi/product/polars)
- Vendor: Polars
- Date: 2026-08-01
- Version: 1.43.2
- Original notes: https://github.com/pola-rs/polars/releases/tag/py-1.43.2
- Permalink: https://whatsnew.fyi/product/polars/releases/1.43.2

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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- **deprecated** — Deprecate casts from Categorical to integer dtypes
- **deprecated** — Deprecate not setting the plan_stage argument in show_graph()
- **changed** — Pushdown len() to concat/union inputs
- **security** — Issue FutureWarning on using from_arrow of ArrowStreamExportable
- **added** — Add infer_schema_files parameter to scan_csv
- **fixed** — Properly propagate enum metadata for iceberg column mapping
- **fixed** — Correctly write parquet field IDs for enums and categoricals
- **fixed** — Fix arrow C interop binview offset
- **fixed** — Fix duplicate hive values in hive pre-partition rewrite
- **fixed** — Double-counted offset for Arrow export of sliced Series(Array)
- **fixed** — Struct/List/Array equality handling in sort and join
- **fixed** — More careful slice pushdown into joins
- **fixed** — Preserve ordering in sliced unions
- **fixed** — Drop input sortedness when casting to a string
- **fixed** — Clear sortedness flags in StringChunked substring kernels
- **fixed** — Bad mask handling when reading optional parquet column
- **fixed** — Any operation on Unknown(Int) and Unknown(Float) should result in Unknown(Float)
- **fixed** — Flip nulls_last after Expr.reverse()
- **fixed** — Fix high blocking thread use in sink_parquet with async local path
- **fixed** — Serialize LazyFrames backed by bytes

##### ⚠️ Deprecations

- Deprecate casts from `Categorical` to integer dtypes (#28525)
- Deprecate not setting the `plan_stage` argument in `show_graph()` (#28391)

##### 🚀 Performance improvements

- Pushdown `len()` to concat/union inputs (#28570)

##### ✨ Enhancements

- Issue FutureWarning on using `from_arrow` of ArrowStreamExportable (#28442)
- Add `infer_schema_files` parameter to `scan_csv` (#28440)

##### 🐞 Bug fixes

- Properly propagate enum metadata for iceberg column mapping (#28580)
- Correctly write parquet field IDs for enums and categoricals (#28581)
- Fix arrow C interop binview offset (#28623)
- Fix duplicate hive values in hive pre-partition rewrite (#28621)
- Double-counted offset for Arrow export of sliced `Series(Array)` (#28602)
- Struct/List/Array equality handling in sort and join (#28601)
- More careful slice pushdown into joins (#28578)
- Preserve ordering in sliced unions (#28576)
- Drop input sortedness when casting to a string (#28574)
- Clear sortedness flags in `StringChunked` substring kernels (#28573)
- Bad mask handling when reading optional parquet column (#28547)
- Any operation on `Unknown(Int)` and `Unknown(Float)` should result in `Unknown(Float)` (#28545)
- Flip `nulls_last` after `Expr.reverse()` (#28572)
- Fix high blocking thread use in sink\_parquet with async local path (#28543)
- Serialize LazyFrames backed by bytes (#28568)
- Release GIL in `SQLContext.execute()` (#28549)
- Propagate `nulls_last` in `function_expr_sortedness` (#28544)
- Incorrect slicing when a join requires sorting (#28541)

##### 🛠️ Other improvements

- Fix duckdb delta extension install collision (#28607)

Thank you to all our contributors for making this release possible!
@BitWeaverDev, @Matt711, @Samoilov2004, @borchero, @dancsi, @dsprenkels, @kdn36, @masumi-ryugo, @nameexhaustion and @ritchie46