Python Polars 0.15.13

✨ Enhancements

• Improve iterating over GroupBy (#6051)
• much faster lazy type-checks (#6064)
• support array-expansion of scalars on frame init from dict (#6034)
• improve error message when writing nested data to… (#6040)

🐞 Bug fixes

• bound complex type from 3.8 to 3.11 (#6071)
• deal with unnest schema expansion in projection pd (#6063)
• correct output dtype for cummin/cumsum/cummax (#6062)
• block streaming on literal series/range (#6058)
• improve handling of dict-type "columns" param on frame-init (#6045)
• Fix typing for DataFrame.select (#6047)
• ndjson struct inference (#6049)
• fix stringcache. latest refactor introduced a hashing error (#6056)
• allow mixed field order and availability in apply that r… (#6041)
• deal with empty structs (#6039)
• fix aggregation that filters out all data (#6036)
• fix diff overflow (#6033)
• keep column names in is_null/is_not_null (#6032)
• keep name when sorting categorical in lexial order (#6029)
• tweaked property/accessor behaviour (#6021)
• properly set null anyvalue if categorical is neste… (#6025)
• Fix from_epoch function signature (#6024)
• Validate estimated_size parameter (#6018)

🛠️ Other improvements

• suggest forward fill in cumsum/cummax (#6061)
• Fix SIM105 issues. (#6042)
• Remove trailing spaces in glimpse output (#6037)
• Remove unnecessary noqa's (#6035)
• Fix flake8-pytest-style errors in tests. (#6031)
• update read_sql and row docstrings (#6028)
• Enable the isort-style import autofix via ruff (#6020)
• Update py-polars/Cargo.lock (#6013)
• Refactor pivot tests (#6012)
• Use ruff instead of isort, flake8 and pyupgrade (#5916)
• Properly deprecate groupby.pivot (#6000)

Thank you to all our contributors for making this release possible!
@alexander-beedie, @ghuls, @ritchie46, @stinodego and @universalmind303

Python Polars 0.15.11

🚀 Performance improvements

• ensure set_at_idx is O(1) (#5977)

✨ Enhancements

• allow eq,ne,lt etc (#5995)
• Improve Expr.is_between API (#5981)
• large speedup for df.iterrows (~200-400%) (#5979)
• updated default table format from "UTF8_FULL" to "UTF8_FULL_CONDENSED" (#5967)
• Access rows as namedtuples (#5966)
• Improve assert_frame_equal messages (#5962)

🐞 Bug fixes

• make weekday tz-aware (#5989)
• fix categorical in struct anyvalue issue (#5987)
• fix invalid boolean simplification (#5976)
• allow empty sort on any dtype (#5975)
• properly deal with categoricals in streaming queries (#5974)

Thank you to all our contributors for making this release possible!
@alexander-beedie, @ritchie46 and @stinodego

Python Polars 0.15.9

🚀 Performance improvements

• improve reducing window function performance ~33% (#5878)

✨ Enhancements

• str.strip with multiple chars (#5929)
• add iterrrows (#5945)
• read decimal as f64 (#5938)
• improve query plan scan formatting (#5937)
• allow all null cast (#5933)
• allow objects in struct types (#5925)
• handle Series init from python sequence of numpy arrays (#5918)
• merge sorted dataframes (#5817)
• impl hex and base64 for binary (#5892)
• Add datatype hierarchy (#5901)
• Add .item() on DataFrame and Series (#5893)
• make get_any_value fallible (#5877)
• Add string representation for data types (#5861)
• directly push all operator result into sink, prev… (#5856)

🐞 Bug fixes

• don't panic on ignored context (#5958)
• don't allow named expression in arr.eval (#5957)
• error on invalid dtype (#5956)
• fix panic in join expressions (#5954)
• block ordered predicates before explode (#5951)
• adhere to schema in arr.eval of empty list (#5947)
• fix from_dict schema_inference=0 (#5948)
• fix arrow nested null conversion (#5946)
• allow None in arr.slice length (#5934)
• fix time to duration cast (#5932)
• error on addition with datetime/time (#5931)
• don't create categoricals in streaming (#5926)
• object filter should keep single chunk (#5913)
• csv, read escaped "" as missing (#5912)
• fix pivot of signed integers (#5909)
• don't allow duplicate columns in read_csv arg (#5908)
• fix latest oob in streaming convertion (#5902)
• adapt k to len in topk (#5888)
• fix lazy swapping rename (#5884)
• fix window function with nullable values; regression due… (#5874)
• improve equality consistency between types (#5873)
• evaluate whole branch expression to determine if r… (#5864)
• fix top_k on empty (#5865)
• fix slice in streaming (#5854)
• Fix type hint for IO *_options arguments (#5852)

🛠️ Other improvements

• Fix docs for sink_parquet (#5952)
• Fix misspelling in LazyFrame docstring (#5917)
• add bin, series.is_sorted and merge_sorted (#5914)

Thank you to all our contributors for making this release possible!
@AnatolyBuga, @alexander-beedie, @cannero, @chitralverma, @dannyvankooten, @johngunerli, @ozgrakkurt, @ritchie46, @stinodego, @winding-lines and @zundertj

Rust Polars 0.26.0

⚠️ Breaking changes

• remove Series::append_array (#5681)
• iso weekday (#5598)

🚀 Performance improvements

• improve reducing window function performance ~33% (#5878)
• impove performance reducing window functions with numeric output ~-14% (#5841)
• set_sorted flag when creating from literal (#5728)
• use sorted fast path in streaming groupby (#5727)
• ensure fast_explode propagates (#5676)
• fix quadratic time complexity of groupby in stream… (#5614)
• Aggregate projection pushdown (#5556)
• improve streaming primitve groupby (#5575)
• vectorize integer vec-hash by using very simple, … (#5572)
• specialized utf8 groupby in streaming (#5535)

✨ Enhancements

• make get_any_value fallible (#5877)
• directly push all operator result into sink, prev… (#5856)
• add sink_parquet (#5480)
• Support parsing more float string representations. (#5824)
• implement mean aggregation for duration (#5807)
• implement sensible boolean aggregates (#5806)
• allow expression as quantile input (#5751)
• accept expression in str.extract_all (#5742)
• tz-aware strptime (#5736)
• Add "fmt_no_tty" feature for formatting support without r… (#5725)
• lazy diagonal concat. (#5647)
• to_struct add upper_bound (#5714)
• inversely scale chunk_size with thread count in s… (#5699)
• add streaming minmax (#5693)
• improve dynamic inference of anyvalues and structs (#5690)
• support is_in for boolean dtype (#5682)
• add a cache to strptime (#5628)
• add nearest interpolation strategy (#5626)
• make cast recursive (#5596)
• add arg_min/arg_max for series of dtype boolean (#5592)
• prefer streaming groupby if partitionable (#5580)
• make map_alias fallible (#5532)
• pl.min & pl.max accept wildcard similar to pl.sum (#5511)
• add predicate pushdown to anonymous_scan (#5467)
• make streaming work with multiple sinks in a sing… (#5474)
• add streaming slice operation (#5466)
• run partial streaming queries (#5464)
• streaming left joins (#5456)
• file statistics so we only (try to) keep smallest table in memory (#5454)
• streaming inner joins. (#5400)
• build_info() provides detailed information how polars was built (#5423)
• add missing width property to LazyFrame (#5431)
• allow regex and wildcard in groupby (#5425)
• Streaming joins architecture and Cross join implementation. (#5339)
• add support for am/pm notation in parse_dates read_csv (#5373)
• add reduce/cumreduce expression as an easier fold (#5364)

🐞 Bug fixes

• fix lazy swapping rename (#5884)
• improve equality consistency between types (#5873)
• evaluate whole branch expression to determine if r… (#5864)
• fix top_k on empty (#5865)
• fix slice in streaming (#5854)
• correct invalid type in struct anyvalue access (#5844)
• don't set fast_explode if null values in list (#5838)
• duration formatting (#5837)
• respect fetch in union (#5836)
• keep f32 dtype in fill_null by int (#5834)
• err on epoch on time dtype (#5831)
• fix panic in hmean (#5808)
• asof join by logical groups (#5805)
• fix parquet regression upstream in arrow2 (#5797)
• Fix lazy cumsum and cumprod result types (#5792)
• fix nested writer (#5777)
• fix(rust, python) Summation on empty series evaluates to Some(0) (#5773)
• empty concat utf8 (#5768)
• projection pushdown with union and asof join (#5763)
• check null values in asof_join + groupby (#5756)
• fix generic streaming groupby on logical types (#5752)
• fix date_range on expressions (#5750)
• fix dtypes in join_asof_by (#5746)
• fix group order in binary aggregation (#5744)
• implement min/max aggregation for utf8 in groupby (#5737)
• fix all_null/sorted into_groups panic (#5733)
• asof join 'by', 'forward' combination (#5720)
• fix pivot on floating point indexes (#5704)
• fix arange with column/literal input (#5703)
• fix double projection that leads to uneven union d… (#5700)
• Fix a bug in floating regex handling used in CSV type inference (#5695)
• fix asof join schema (#5686)
• fix owned arithmetic schema (#5685)
• take glob into account in scan_csv 'with_schema_mo… (#5683)
• fix boolean schema in agg_max/min (#5678)
• fix boolean arg-max if all equal (#5680)
• early error on duplicate names in streaming groupby (#5638)
• fix streaming groupby aggregate types (#5636)
• convert panic to err in concat_list (#5637)
• fix dot diagram of single nodes (#5624)
• fix dynamic struct inference (#5619)
• keep dtype when eval on empty list (#5597)
• fix ternary with list output on empty frame (#5595)
• fix tz-awareness of truncate (#5591)
• check chunks before doing chunked_id join optimiza… (#5589)
• invert cast_time_zone conversion (#5587)
• asof join ensure join column is not dropped when '… (#5585)
• fix ub due to invalid dtype on splitting dfs (#5579)
• fix(rust, python); fix projection pushdown in asof joins (#5542)
• streaming hstack allow duplicates (#5538)
• fix streaming empty join panic (#5534)
• fix duplicate caches in cse and prevent quadratic … (#5528)
• allow appending categoricals that are all null (#5526)
• tz-aware strftime (#5525)
• make 'truncate' tz-aware (#5522)
• fix coalesce expreession expansion (#5521)
• fix nested aggregatin in when then and window expr… (#5520)
• fix sort_by expression if groups already aggregated (#5518)
• fix bug in batched parquet reader that dropped dfs… (#5506)
• fix bugs in skew and kurtosis (#5484)
• compute correct offset for streaming join on multi… (#5479)
• return error on invalid sortby expression (#5478)
• add missing AnyValueBuffer specialisation for Duration dtype (#5436)
• fix freeze/stall when writing more than 2^31 string values to parquet (#5366)
• properly handle json with unclosed strings (#5427)
• fix null poisoning in rank operation (#5417)
• correct expr::diff dtype for temporal columns (#5416)
• fix cse for nested caches (#5412)
• don't set sorted flag in argsort (#5410)
• explicit nan comparison in min/max agg (#5403)
• Correct CSV row indexing (#5385)

🛠️ Other improvements

• Update rustc and fix clippy (#5880)
• update arrow (#5862)
• move join dispatch to polars-ops (#5809)
• Remove dbg statement from union (#5791)
• Continue removing compilation warnings (#5778)
• shrink anyvalue size (#5770)
• update arrow (#5766)
• chore(rust,python) Change allow_streaming to streaming (#5747)
• remove rev-map from ChunkedArray (#5721)
• simplify fast projection by schema (#5716)
• Reindent df! docs code (#5698)
• remove Series::append_array (#5681)
• Remove unused symbols and uneeded mut qualifier (#5672)
• Include license files in Rust crates (#5675)
• Use NaiveTime::from_hms_opt instead of NaiveTime::from_hms (#5664)
• use xxhash3 for string types (#5617)
• iso weekday (#5598)
• Improve contributing guide (#5558)
• streaming improvements (#5541)
• Refer to DataFrame::unique instead of distinct (#5482)
• don't panic if part of query cannot run strea… (#5458)
• make generic join builder more dry (#5439)
• use IdHash for streaming groupby generic (#5435)
• fix freeze/stall when writing more than 2^31 string values to parquet (#5366)

Thank you to all our contributors for making this release possible!
@AnatolyBuga, @CalOmnie, @Kuhlwein, @MarcoGorelli, @OneRaynyDay, @YuRiTan, @alexander-beedie, @andrewpollack, @ankane, @braaannigan, @chitralverma, @dannyvankooten, @ghais, @ghuls, @jjerphan, @matteosantama, @messense, @owrior, @pickfire, @ritchie46, @s1ck, @sa-, @slonik-az, @sorhawell, @stinodego, @universalmind303 and @zundertj

Python Polars 0.15.7

🚀 Performance improvements

• impove performance reducing window functions with numeric output ~-14% (#5841)

✨ Enhancements

• allow more pyarrow literals (#5842)
• add sink_parquet (#5480)
• release GIL when writing (#5830)
• Support parsing more float string representations. (#5824)
• implement mean aggregation for duration (#5807)
• implement sensible boolean aggregates (#5806)

🐞 Bug fixes

• correct invalid type in struct anyvalue access (#5844)
• don't set fast_explode if null values in list (#5838)
• duration formatting (#5837)
• respect fetch in union (#5836)
• keep f32 dtype in fill_null by int (#5834)
• fix(python): fix delta issues (#5802)
• err on epoch on time dtype (#5831)
• fix panic in hmean (#5808)
• asof join by logical groups (#5805)

🛠️ Other improvements

• lazily import connectorx (#5835)

Thank you to all our contributors for making this release possible!
@chitralverma, @ghuls and @ritchie46

Python Polars 0.15.6

🐞 Bug fixes

• fix struct dataset (#5798)
• fix parquet regression upstream in arrow2 (#5797)

🛠️ Other improvements

• remove unused cmake-rs patch (#5794)

Thank you to all our contributors for making this release possible!
@OneRaynyDay, @messense, @ritchie46 and @universalmind303

Python Polars 0.15.3

🚀 Performance improvements

• set_sorted flag when creating from literal (#5728)
• use sorted fast path in streaming groupby (#5727)

✨ Enhancements

• push down predicates to pyarrow datasets (#5780)
• Support for reading delta lake tables (#5761)
• Add DataFrame.glimpse() (#5622)
• allow expression as quantile input (#5751)
• accept expression in str.extract_all (#5742)
• tz-aware strptime (#5736)
• lazy diagonal concat. (#5647)
• to_struct add upper_bound (#5714)

🐞 Bug fixes

• fix(rust, python) Summation on empty series evaluates to Some(0) (#5773)
• empty concat utf8 (#5768)
• projection pushdown with union and asof join (#5763)
• check null values in asof_join + groupby (#5756)
• fix generic streaming groupby on logical types (#5752)
• fix date_range on expressions (#5750)
• fix dtypes in join_asof_by (#5746)
• fix group order in binary aggregation (#5744)
• implement min/max aggregation for utf8 in groupby (#5737)
• fix all_null/sorted into_groups panic (#5733)
• address several edge-cases found when asserting NaN equality (#5732)
• asof join 'by', 'forward' combination (#5720)

🛠️ Other improvements

• add DataFrame.pearson_corr to reference (#5772)
• Parse fixed timezone offsets without pytz (#5769)
• chore(rust,python) Change allow_streaming to streaming (#5747)
• Remove pyarrow nightlies requirement. (#5719)
• fix incorrect accepted type in df.write_csv (#5715)

Thank you to all our contributors for making this release possible!
@AnatolyBuga, @MarcoGorelli, @alexander-beedie, @andrewpollack, @braaannigan, @chitralverma, @ghuls, @ritchie46, @sa- and @zundertj

Python Polars 0.15.2

🚀 Performance improvements

• ensure fast_explode propagates (#5676)

✨ Enhancements

• Series.get_chunks (#5701)
• inversely scale chunk_size with thread count in s… (#5699)
• add streaming minmax (#5693)
• Support large page sizes on aarch64 linux builds (#5694)
• improve dynamic inference of anyvalues and structs (#5690)
• support is_in for boolean dtype (#5682)
• add notebook html repr for Series (#5653)

🐞 Bug fixes

• fix pivot on floating point indexes (#5704)
• fix arange with column/literal input (#5703)
• fix double projection that leads to uneven union d… (#5700)
• Fix Series -> Expr dispatch for @Property methods (#5689)
• fix asof join schema (#5686)
• fix owned arithmetic schema (#5685)
• take glob into account in scan_csv 'with_schema_mo… (#5683)
• fix boolean schema in agg_max/min (#5678)
• fix boolean arg-max if all equal (#5680)
• respect python objects read method even if filename is f… (#5677)
• Fix DataFrame.n_chunks return type (#5650)

🛠️ Other improvements

• Parametrize test_parquet_datetime (#5696)
• Function and lazy function doctrings (#5657)
• Fix formatting (#5658)

Thank you to all our contributors for making this release possible!
@alexander-beedie, @ankane, @braaannigan, @ghais, @ghuls, @jjerphan, @pickfire, @ritchie46, @stinodego and @zundertj

Python Polars 0.15.1

⚠️ Breaking changes

• Update Expr.sample signature and change random seeding (#4648)
• rollup breaking changes (#5602)
• iso weekday (#5598)
• Change null_equal default to True for Series.series_equal (#5051)
• rollup breaking changes (#5602)

🚀 Performance improvements

• fix quadratic time complexity of groupby in stream… (#5614)
• Improve performance of indexing operations on Series. (#5610)
• Aggregate projection pushdown (#5556)

✨ Enhancements

• add a cache to strptime (#5628)
• add nearest interpolation strategy (#5626)
• Update Expr.sample signature and change random seeding (#4648)
• Change null_equal default to True for Series.series_equal (#5051)
• make cast recursive (#5596)
• add arg_min/arg_max for series of dtype boolean (#5592)

🐞 Bug fixes

• early error on duplicate names in streaming groupby (#5638)
• fix streaming groupby aggregate types (#5636)
• convert panic to err in concat_list (#5637)
• fix dot diagram of single nodes (#5624)
• fix dynamic struct inference (#5619)
• tz-aware filtering (#5603)
• keep dtype when eval on empty list (#5597)
• fix ternary with list output on empty frame (#5595)
• fix tz-awareness of truncate (#5591)
• check chunks before doing chunked_id join optimiza… (#5589)
• invert cast_time_zone conversion (#5587)
• asof join ensure join column is not dropped when '… (#5585)

🛠️ Other improvements

• Remaining docstring examples for frame and lazyframe (#5630)
• use xxhash3 for string types (#5617)
• only trigger build.rs file if that file itself has cha… (#5618)
• iso weekday (#5598)
• Merge release workflows (#5564)
• Fix broken lint workflow (#5584)

Thank you to all our contributors for making this release possible!
@Kuhlwein, @braaannigan, @ghuls, @matteosantama, @ritchie46 and @stinodego

Python Polars 0.14.31

🚀 Performance improvements

• improve streaming primitve groupby (#5575)
• vectorize integer vec-hash by using very simple, … (#5572)

✨ Enhancements

• prefer streaming groupby if partitionable (#5580)

🐞 Bug fixes

• fix ub due to invalid dtype on splitting dfs (#5579)

🛠️ Other improvements

• Remove old Python changelog file (#5577)
• namespace registration docs update (#5565)
• Improve contributing guide (#5558)

Thank you to all our contributors for making this release possible!
@alexander-beedie, @ghuls, @ritchie46 and @stinodego