# Polars 1.34.0-beta.5 — Python Polars 1.34.0-beta.5

- Product: Polars (https://whatsnew.fyi/product/polars)
- Vendor: Polars
- Date: 2025-10-01
- Version: 1.34.0-beta.5
- Original notes: https://github.com/pola-rs/polars/releases/tag/py-1.34.0-beta.5
- Permalink: https://whatsnew.fyi/product/polars/releases/1.34.0-beta.5
- Labels: Pre-release

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** — Add LazyFrame.sink_batches and LazyFrame.collect_batches
- **added** — Add support to output dt.total_{}() duration values as fractionals
- **added** — Add unstable hidden_file_prefix parameter to scan_parquet
- **added** — Add support for unsigned 128-bit integers
- **added** — Add unstable pl.Config.set_default_credential_provider
- **added** — Add opt-in unstable functionality to load interval types as Struct
- **added** — Support unique / n_unique / arg_unique for array columns
- **added** — Support scanning from file:/path URIs
- **added** — Add support to display lazy query plan in marimo notebooks without needing to install matplotlib or mermaid
- **added** — Support reading parquet metadata from cloud storage
- **changed** — Implement maintain_order for cross join
- **changed** — Deterministic import order for Python Polars package variants
- **changed** — Avoid forcing a pyarrow dependency in read_excel when using the default calamine engine
- **changed** — Use fixed-scale Decimals
- **changed** — Roundtrip BinaryOffset type through Parquet
- **fixed** — Make Categories pickleable
- **fixed** — Shift on array within list
- **fixed** — Support reading of mixed compressed/uncompressed IPC buffers
- **fixed** — Overflow in slice-slice optimization
- **fixed** — Method dt.month_end was unnecessarily raising when the month-start timestamp was ambiguous

##### 🏆 Highlights

- Add `LazyFrame.{sink,collect}_batches` (#23980)
- Deterministic import order for Python Polars package variants (#24531)

##### 🚀 Performance improvements

- Pushdown filter with `strptime` if input is literal (#24694)
- Avoid copying expanded paths (#24669)
- Relax filter expr ordering (#24662)
- Remove unnecessary `groups` call in `aggregated` (#24651)
- Skip files in `scan_iceberg` with filter based on metadata statistics (#24547)
- Push row\_index predicate for all scan types (#24537)
- Perform integer in-filtering for Parquet inequality predicates (#24525)
- Stop caching Parquet metadata after 8 files (#24513)
- Native streaming `.mode()` expression (#24459)

##### ✨ Enhancements

- Implement maintain\_order for cross join (#24665)
- Add support to output `dt.total_{}()` duration values as fractionals (#24598)
- Avoid forcing a `pyarrow` dependency in `read_excel` when using the default "calamine" engine (#24655)
- Support scanning from `file:/path` URIs (#24603)
- Log which file the schema was sourced from, and which file caused an extra column error (#24621)
- Add `LazyFrame.{sink,collect}_batches` (#23980)
- Deterministic import order for Python Polars package variants (#24531)
- Add support to display lazy query plan in marimo notebooks without needing to install matplotlib or mermaid (#24540)
- Add unstable `hidden_file_prefix` parameter to `scan_parquet` (#24507)
- Use fixed-scale Decimals (#24542)
- Add support for unsigned 128-bit integers (#24346)
- Add unstable `pl.Config.set_default_credential_provider` (#24434)
- Roundtrip `BinaryOffset` type through Parquet (#24344)
- Add opt-in unstable functionality to load interval types as `Struct` (#24320)
- Support reading parquet metadata from cloud storage (#24443)
- Add user guide section on AWS role assumption (#24421)
- Support `unique` / `n_unique` / `arg_unique` for `array` columns (#24406)

##### 🐞 Bug fixes

- Make `Categories` pickleable (#24691)
- Shift on array within list (#24678)
- Fix handling of `AggregatedScalar` in `ApplyExpr` single input (#24634)
- Support reading of mixed compressed/uncompressed IPC buffers (#24674)
- Overflow in slice-slice optimization (#24658)
- Package discovery for `setuptools` (#24656)
- Add type assertion to prevent out-of-bounds in `GenericFirstLastGroupedReduction` (#24590)
- Remove inclusion of polars dir in runtime sdist/wheel (#24654)
- Method `dt.month_end` was unnecessarily raising when the month-start timestamp was ambiguous (#24647)
- Widen `from_dicts` to `Iterable[Mapping[str, Any]]` (#24584)
- Fix `unsupported arrow type Dictionary` error in `scan_iceberg()` (#24573)
- Raise Exception instead of panic when unnest on non-struct column (#24471)
- Include missing feature dependency from `polars-stream/diff` to `polars-plan/abs` (#24613)
- Newline escaping in streaming show\_graph (#24612)
- Do not allow inferring (`-1`) the dimension on any `Expr.reshape` dimension except the first (#24591)
- Sink batches early stop on in-memory engine (#24585)
- More precisely model expression ordering requirements (#24437)
- Panic in zero-weight rolling mean/var (#24596)
- Decimal \<-> literal arithmetic supertype rules (#24594)
- Match various aggregation return types in the streaming engine with the in-memory engine (#24501)
- Validate list type for list expressions in planner (#24589)
- Fix `scan_iceberg()` storage options not taking effect (#24574)
- Have `log()` prioritize the leftmost dtype for its output dtype (#24581)
- CSV pl.len() was incorrect (#24587)
- Add support for float inputs for duration types (#24529)
- Roundtrip empty string through hive partitioning (#24546)
- Fix potential OOB writes in unaligned IPC read (#24550)
- Fix regression error when scanning AWS presigned URL (#24530)
- Make `PlPath::join` for cloud paths replace on absolute paths (#24514)
- Correct dtype for cum\_agg in streaming engine (#24510)
- Restore support for np.datetime64() in pl.lit() (#24527)
- Ignore Iceberg list

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