# Polars 1.23.0 — Python Polars 1.23.0

- Product: Polars (https://whatsnew.fyi/product/polars)
- Vendor: Polars
- Date: 2025-02-23
- Version: 1.23.0
- Original notes: https://github.com/pola-rs/polars/releases/tag/py-1.23.0
- Permalink: https://whatsnew.fyi/product/polars/releases/1.23.0

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** — Toggle projection pushdown for eager rolling
- **changed** — Fix pathologic rolling + group-by performance and memory explosion
- **changed** — Add sampling to new-streaming equi join to decide between build/probe side
- **added** — Implement i128 to str cast
- **added** — Connect polars-cloud
- **added** — Version DSL
- **changed** — Make user facing binary formats mostly self describing
- **added** — Filter hive files using predicates in new streaming
- **added** — Add negative slicing to new streaming multiscan
- **changed** — Allow iterable of frames as input to align_frames
- **added** — Implement sorted flags for struct series
- **added** — Support reading arrow Map type from Delta
- **added** — Add a dedicated remove method for DataFrame and LazyFrame
- **changed** — Rename credentials parameter to credential in CredentialProviderAzure
- **added** — Implement merge_sorted for struct
- **added** — Add positive slice for new streaming MultiScan
- **added** — Add SQL support for the DELETE statement
- **added** — Add row index to new streaming multiscan
- **fixed** — Method dt.ordinal_day was returning UTC results as opposed to those on the local timestamp
- **fixed** — Use Kahan summation for rolling sum kernels to fix numerical stability issues
- **fixed** — Add scalar checks for n and fill_value parameters in shift
- **fixed** — Upcast small integer dtypes for rolling sum operations
- **fixed** — Don't silently produce null values from invalid input to pl.datetime and pl.date

##### 🚀 Performance improvements

- Toggle projection pushdown for eager rolling (#21405)
- Fix pathologic `rolling + group-by` performance and memory explosion (#21403)
- Add sampling to new-streaming equi join to decide between build/probe side (#21197)

##### ✨ Enhancements

- Implement i128 -> str cast (#21411)
- Connect polars-cloud (#21387)
- Version DSL (#21383)
- Make user facing binary formats mostly self describing (#21380)
- Filter hive files using predicates in new streaming (#21372)
- Add negative slicing to new streaming multiscan (#21219)
- Allow iterable of frames as input to `align_frames` (#21209)
- Implement sorted flags for struct series (#21290)
- Support reading arrow Map type from Delta (#21330)
- Add a dedicated `remove` method for `DataFrame` and `LazyFrame` (#21259)
- Rename `credentials` parameter to `credential` in `CredentialProviderAzure` (#21295)
- Implement `merge_sorted` for struct (#21205)
- Add positive slice for new streaming MultiScan (#21191)
- Don't take in rewriting visitor (#21212)
- Add SQL support for the `DELETE` statement (#21190)
- Add row index to new streaming multiscan (#21169)
- Improve DataFrame fmt in explain (#21158)

##### 🐞 Bug fixes

- Method `dt.ordinal_day` was returning UTC results as opposed to those on the local timestamp (#21410)
- Use Kahan summation for rolling sum kernels. Fix numerical stability issues (#21413)
- Add scalar checks for `n` and `fill_value` parameters in `shift` (#21292)
- Upcast small integer dtypes for rolling sum operations (#21397)
- Don't silently produce null values from invalid input to `pl.datetime` and `pl.date` (#21013)
- Allow duration multiplied w/ primitive to propagate in IR schema (#21394)
- Struct arithmetic broadcasting behavior (#21382)
- Prefiltered optional plain primitive kernel (#21381)
- Panic when projecting only row index from IPC file (#21361)
- Properly update groups after `gather` in aggregation context (#21369)
- Mark test as may\_fail\_auto\_streaming (#21373)
- Properly set `fast_unique` in EnumBuilder (#21366)
- Rust test race condition (#21368)
- Fix unequal DataFrame column heights from parquet hive scan with filter (#21340)
- Fix ColumnNotFound error selecting `len()` after semi/anti join (#21355)
- Merge Parquet nested and flat decoders (#21342)
- Incorrect atomic ordering in Connector (#21341)
- Method `dt.offset_by` was discarding month and year info if day was included in offset for timezone-aware columns (#21291)
- Fix pickling `polars.col` on Python versions \<3.11 (#21333)
- Fix duplicate column names after join if suffix already present (#21315)
- Skip Batches Expression for boolean literals (#21310)
- Fix performance regression for eager `join_where` (#21308)
- Fix incorrect predicate pushdown for predicates referring to right-join key columns (#21293)
- Panic in `to_physical` for series of arrays and lists (#21289)
- Resolve deadlock due to leaking in Connector recv drop (#21296)
- Incorrect result for merge\_sorted with lexical categorical (#21278)
- Add `Int128` path for `join_asof` (#21282)
- Categorical min/max returning String dtype rather than Categorical (#21232)
- Checking overflow in Sliced function (#21207)
- Adding a struct field using a literal raises InvalidOperationError (#21254)
- Return nulls for `is_finite`, `is_infinite`, and `is_nan` when dtype is `pl.Null` (#21253)
- Account for minor change in new `connectorx` release (#21277)
- Properly implement and test Skip Batch Predicate (#21269)
- Infinite recursion when broadcasting into struct zip\_outer\_validity (#21268)
- Deadlock due to bad logic in new-streaming join sampling (#21265)
- Incorrect result for top\_k/bottom\_k when input is sorted (#21264)
- UTF-8 validation of nested string slice in Parquet (#21262)
- Raise instead of panicking when casting a Series to a Struct with the wrong number of fields (#21213)
- Defer credential provider resolution to take place at query collection instead of construction (#21225)
- Do not pani

_[Truncated at 4000 characters — full notes: https://github.com/pola-rs/polars/releases/tag/py-1.23.0]_