Python Polars 0.19.4

🏆 Highlights

• support 'hive partitioning' aware readers (#11284)
• natively support reading parquet for aws, gcp and azure (#11210)
• Add support for Iceberg (#10375)
• The great expressification by @reswqa (#11320, #11344, #11313, #11257, #11288, #11275, #11197, #11167, #11155)

⚠️ Deprecations

• Add disable_string_cache (#11020)

🚀 Performance improvements

• improve dynamic_groupby_iter (#11341)
• improve and fix rolling windows by linear scanning (#11326)
• faster init from pydantic models that have a small number of fields, and support direct init from SQLModel data (often used with FastAPI) (#11263)
• improve outer join materialization (#11241)
• use ryu and itoa for primitive serialization (#11193)
• use try-binary-elementwise instead of try-binary-elementwise-values in dt_truncate (#11189)
• Using cache for str.contains regex compilation (#11183)

✨ Enhancements

• introduce 'label' instead of 'truncate' in group_by_dynamic, which can take label='right' (#11337)
• Expressify list.shift (#11320)
• top_k and bottom_k supports pass an expr (#11344)
• add "pyxlsb" engine support to read_excel (for excel binary workbook files) (#11248)
• support 'hive partitioning' aware readers (#11284)
• str.strip_chars supports take an expr argument (#11313)
• sample n can take an expr (#11257)
• Add disable_string_cache (#11020)
• clip supports expr arguments and physical numeric dtype (#11288)
• Introduce list.drop_nulls (#11272)
• str.splitn and split_exact can take an expr argument by (#11275)
• introduce ambiguous option for dt.round (#11269)
• Adds NULLIF and COALESCE SQL functions (#11124)
• better tree-formatting representation (#11176)
• natively support reading parquet for aws, gcp and azure (#11210)
• Expressify str.strip_prefix & suffix (#11197)
• Add support for Iceberg (#10375)
• list.join's separator can be expression (#11167)
• argument every of datetime.truncate can be expression (#11155)

🐞 Bug fixes

• Fix Series.__contains__ for None values and implement is_in for null Series (#11345)
• don't panic on multi-nodes in streaming conversion (#11343)
• ensure trailing quote is written for temporal data when CSV quote_style is non-numeric (#11328)
• clarify has_validity docstring and fix several cases where the presence of a bitmask was used to incorrectly infer the existence of null values (#11319)
• fix empty Series construction edge-case with Struct dtype (#11301)
• DataFrame init from collections.namedtuple values (#11314)
• Exclude functools wrapper frames in find_stacklevel (#11292)
• set partitions independent of thread pool (#11304)
• address VSCode issue with autocomplete on selector expressions in editor/console (#11235)
• consume duplicates in rolling_by window (#11261)
• handle url encoded paths in objectpath creation (#11240)
• use POOL when writing csv (#11222)
• don't conflate saved Config JSON string with file path (#11098)
• is_in for bool evaluate has_false incorrectly (#11217)
• improve handling of database drivers that can return arrow data (#11201)
• fix nullable filter mask in group_by (#11207)
• replace n-th in filter (#11206)
• fix translation of Series-nested datetime/date values for scan_pyarrow predicates (#11195)
• address unexpected expression name from use of unary - or + operators (#11158)
• impl hash for more function expr (#11182)
• list.join's separator can be expression (#11167)
• Add some missing expr type hint for series (#11171)
• consistently use negative every as the default for offset in group_by_dynamic (#11164)
• Make pl.struct serializable (#11169)
• only raise on actual parameter collision when "dtypes" specified in read_excel "read_csv_options" (#11162)
• propagate null value for str/binary starts/ends_with and contains (#11141)

🛠️ Other improvements

• simplify/clarify group_by_dynamic examples (#11335)
• tighten assert_frame_equal for LazyFrames (don't collect until after the schema has been checked) (#11331)
• unify display for namespaced function expr (#11342)
• add lazy pivot example (#11325)
• Use GITHUB_TOKEN to get contributor information for docs (#11321)
• Enable version warning banner (#11322)
• cross-reference null_count from has_validity (clarifies the correct way to check for nulls) (#11323)
• Pin pydantic in dev requirements <2.4.0 (#11312)
• remove default auto-explode for map_many_private (#11270)
• Add type alias IntoExprColumn (#11296)
• update a few dependencies (#11283)
• Properly skip ADBC test (#11282)
• Fix some minor Makefile issues (#11276)
• update sponsors (#11271)
• parametric tests for group_by_rolling (#11262)
• Make some list function expr non-anonymous (#11230)
• Mention the performant feature only once (#11223)
• remove unneeded indirection (#11233)
• remove unneeded mutex around object-store (#11224)
• clarify every/period/offset in group_by_dynamic (#11175)
• Fix read_database batch_size docstring (#11132)

Thank you to all our contributors for making this release possible!
@ByteNybbler, @Cheukting, @Fokko, @Hofer-Julian, @MarcoGorelli, @SeanTroyUWO, @alexander-beedie, @billylanchantin, @jonashaag, @mcrumiller, @orlp, @ptiza, @reswqa, @ritchie46, @stinodego and @universalmind303