py-1.43.2

EricLBuehler/mistral.rspy-1.43.2Aug 1, 2026by github-actions[bot]

AI Summary

A Python Polars patch release aligning with the Rust version, focusing on deprecations and bug fixes. Key highlights include the deprecation of Categorical to integer casts and fixes for metadata handling in Iceberg and Arrow interop.

Key Highlights

  • Deprecation of casts from Categorical to integer dtypes
  • Performance improvement pushing len() to concat/union inputs
  • Fixes for Iceberg metadata and Arrow buffer offsets

Full Release Notes

## ⚠️ 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