Narwhals v1.23.0

Changes

• ci: downstream test for formulaic (#1817)
• docs: Removed class, added polars to the table, str.head and str.tail are a… (#1801)

✨ Enhancements

• feat: deprecate maintain_order in Expr.unique and LazyFrame.tail (but keep around in stable.v1) (#1839)
• feat: track whether expressions change length but don't aggregate, and only allow length-changing expressions if they're followed by aggregations in the lazy API (#1828)
• feat: add DuckDB: nw.nth, nw.sum_horizontal, nw.concat_str, group_by with drop_null_keys (#1832)
• feat: remove eager_or_interchange from from_native in main namespace, switch Ibis' support from interchange to lazy in main namespace (but preserve status-quo in stable.v1) (#1829)
• feat: add is_nan and is_finite for duckdb, is_nan for pyspark (#1825)
• chore: rename time zone tests (#1830)
• feat: Deprecate Expr.arg_true (but keep Series.arg_true, and keep both available in stable.v1) (#1827)
• feat: add Expr.dt methods to PySpark (#1835)
• feat: add pyspark str namespace to_datetime (#1826)
• feat: add total duration methods for DuckDB (#1831)
• feat: add .over method for SparkLikeExpr (#1808)
• feat: pyspark group by n_unique and no aggregation (#1819)
• feat: Disallow order-dependent expressions from being passed to nw.LazyFrame (#1806)
• feat: add SparkExpr.cast for basic types (#1812)
• feat: pyspark and duckdb Expr.name namespace (#1809)
• feat: add AnonymousExprError (#1816)
• feat: deprecate Expr.head, Expr.tail, Expr.sort, Expr.gather_every, Expr.sample (but keep them in stable.v1) (#1791)
• feat: add duckdb dataframe drop_nulls (#1811)
• feat: add DataFrame and Series to_polars (#1803)
• feat: add support for SparkLikeNamespace.when (#1805)

🐞 Bug fixes

• fix: when/then/otherwise output name was not consistent across backends (#1833)
• fix: raise on shape mismatch in filter (#1814)
• patch: fix when-then double lit case (#1810)

🛠️ Other improvements

• chore: simplify imports (#1838)
• test: fixup test suite for cudf.pandas (#1837)
• test: decouple pyspark constructor from pandas (#1834)
• chore: refactor pandas-like narwhals_to_native_dtype (#1824)
• chore: refactor isinstance_or_issubclass to allow tuples (#1820)

Thank you to all our contributors for making this release possible!
@Dhanunjaya-Elluri, @EdAbati, @FBruzzesi, @MarcoGorelli, @luke396, @marvinl803 and @raisadz

Narwhals v1.22.0

Changes

✨ Enhancements

• feat: improve error message on check_columns_exist (#1799)
• feat: DuckDB date (#1798)
• feat: DuckDB dt.to_string (#1794)
• feat: DuckDB dt.ordinal_day (#1796)
• feat: DuckDB dt.weekday (#1795)
• feat: add extra overload for concat for when it is not known statically whether inputs are eager or lazy (#1783)
• feat: duckdb replace_all with regex (#1784)
• feat: implement anti-join, str.len_chars, and null_count for DuckDB (#1777)
• feat: SparkLikeNamespace methods (#1779)
• feat: add SparkLikeStrNamespace methods (#1781)
• feat: add all, any and null_count Spark Expressions (#1724)
• feat: add missing dunder methods in SparkLikeExpr and SparkLikeNamespace.lit (#1708)
• feat: implement cross-join for duckdb (#1773)
• feat: semi-join for duckdb (#1767)
• feat: implement n_unique for DuckDB (#1762)
• feat: implement when/then/otherwise for DuckDB (#1759)
• feat: add few missing SparkLikeExpr methods (#1721)

🐞 Bug fixes

• fix: to_py_scalar was raising for decimals (#1800)
• fix: fix skew for duckdb with fewer than 3 elements (#1785)
• fix: duckdb join was failing if column names contained spaces (#1775)
• fix: parse_version was not parsing duckdb pre-preleases correctly (#1763)
• fix: update Spark min version in utils.py (#1760)

📖 Documentation

• docs: remove docstring examples from narwhals/stable/v1 (#1797)
• docs: Restore API complentess page (#1788)
• docs: Increased width for content (#1769)
• docs: fix is_between type hint in signature (#1766)

🛠️ Other improvements

• chore: factor out check_columns_exist (#1792)
• chore: split namespaces out from expr and series (#1782)
• chore: move pyspark tests into main test suite (#1761)
• chore: dask nightly (#1768)
• chore: Remove some unnecessary trailing commas (#1757)
• chore: validate predicates in nw.when one level higher (#1756)
• chore: remove some expr._kwargs defaults (#1747)
• chore: Filter left join warning (#1753)

Thank you to all our contributors for making this release possible!
@DeaMariaLeon, @Dhanunjaya-Elluri, @EdAbati, @FBruzzesi, @MarcoGorelli, @camriddell, @lucas-nelson-uiuc, @marvinl803 and @raisadz

Narwhals v1.21.1

Changes

✨ Enhancements

• feat: add Series|Expr.rank (#1342)

🐞 Bug fixes

• fix: fix license classifier (#1751)

📖 Documentation

• docs: update api-completeness with duckdb (#1740)

🛠️ Other improvements

• test: remove cudf from tests/expr_and_series/replace_time_zone_test.py::test_replace_time_zone_none[cudf] (#1748)
• chore: filter old pyarrow/pandas warnings we cant do anything about (#1746)
• [pre-commit.ci] pre-commit autoupdate (#1741)

Thank you to all our contributors for making this release possible!
@AlessandroMiola, @Dhanunjaya-Elluri, @EdAbati, @FBruzzesi, @MarcoGorelli, @anopsy

Narwhals v1.21.0

Changes

• fix: always pass Column to pandas.spark.functions (#1712)
• tests: add 'core' to nox dependencies (#1713)
• feat: add weekday to Pandas, Dask and Arrow dt namespaces (#1680)
• Link to Avoiding the UserWarning error while using Pandas group_by page when warning is thrown (#1683)

✨ Enhancements

• feat: Implement partial "lazy" support for DuckDB (even with this PR, DuckDB support is work-in-progress!) (#1725)
• feat: validate library minimum version in compliant objects (#1727)
• feat: enable to cast to Struct dtype (#1717)
• feat: Expressify clip arguments (#1709)
• feat: add is_nan expression & series method (#1625)
• feat: show native object (if possible) in repr (#1702)
• feat: add sum and sum_horizontal for SparkLike (#1693)
• feat: add some SparkLikeLazyFrame methods (#1633)

🐞 Bug fixes

• fix: fix broken link from warning (#1732)
• fix: nw.lit(date, dtype=nw.Date), loosen Dask minimum back to 2024.8 (#1730)
• chore: simplify definitions of rhs expressions, bump dask minimum to 2024.10 (#1720)
• fix: dask group by with kwargs (#1676)
• fix: DaskLazyFrame and ArrowDataFrame .with_row_index column order (#1706)
• fix: scalar reductions on empty inputs (#1715)
• fix: remove maintain_order from LazyFrame.unique (#1687)
• fix: modin dtype interoperability (#1692)
• fix: Dask was raising for scalar vs Series binary operations (#1684)
• fix: casting to List for cudf (#1686)

📖 Documentation

• docs: Expr method' docstrings (#1733)
• docs: let nw.LazyFrame docstrings examples run on Polars and Dask only (#1700)
• docs: update null handling page with is_nan reference (#1716)
• docs: add spark-like in backend completeness (#1710)
• docs: Series method' docstrings (#1699)
• docs: DataFrame method' docstrings (#1688)

🛠️ Other improvements

• test: catch some cudf failures (#1735)
• chore: refactor root_names and output_names tracking (#1731)
• tests: remove unnecessary pytest filterwarnings (#1691)
• chore: remove some lazy tests (#1719)
• fix: Catch cuDF warning for concat with empty elements, and ComputeError for non-float is_nan (#1718)
• chore: use None instead of float('nan') to check for null values in tests (#1697)
• test: allow to run tests for Polars[gpu] (#1698)
• test: Make constructors configurable when running tests (#1694)

Thank you to all our contributors for making this release possible!
@AlessandroMiola, @DeaMariaLeon, @EdAbati, @FBruzzesi, @MarcoGorelli, @camriddell, @dependabot, @dependabot[bot], @lucas-nelson-uiuc and @lucianosrp

Narwhals v1.20.1

Changes

🐞 Bug fixes

• fix: is_duplicated was returning wrong-length result for PyArrow and Dask (#1679)

Thank you to all our contributors for making this release possible!
@DeaMariaLeon and @MarcoGorelli

Narwhals v1.20.0

Changes

🚀 Performance improvements

• chore, perf: arrow cat namespace (#1663)

✨ Enhancements

• feat: raise informative error message when grouping by expressions (#1677)
• feat: expressify lower_bound and upper_bound in is_between (#1672)
• feat: Relax cuDF minimum version to 24.10.0 (#1649)
• Feat/add collect schema to interchange dfs (#1646)
• feat: Add support for .shift(n).over('col') for pandas-like DataFrames (#1627)

🐞 Bug fixes

• fix: pyspark group by with kwargs (#1665)

📖 Documentation

• docs: use IntoDataFrameT/IntoFrameT in docs (#1664)
• docs: Add return type description for more series namespace (#1675)
• docs: Add more return type descriptions for Series (#1674)
• docs: add return type descriptions for cum_count, cum_max, cum_min, cum_prod, cum_sum in Series (#1673)
• docs: add return type descriptions to Series arg_true, cast, clip, count (#1667)
• docs: Add return descriptions to Series's abs, alias, all, any methods for clarity (#1653)

🛠️ Other improvements

• chore: pyarrow do not combine chunks (#1662)
• chore: flatten subset in unique one level up (#1671)
• test: add test for nw.Expr|Series.str.contains with literal=True (#1670)
• test: check keys are in the same order in assert_equal_data (#1668)
• ci: improve publish ci to use env vars (#1652)
• chore: use __narwhals_namespace__ more (#1658)
• ci: split dev from extra (#1655)

Thank you to all our contributors for making this release possible!
@AlessandroMiola, @ClaudioSalvatoreArcidiacono, @Dhanunjaya-Elluri, @FBruzzesi, @MarcoGorelli and @luke396

Narwhals v1.19.1

Changes

🚀 Performance improvements

• perf: avoid merge in pandas groupby (#1638)

✨ Enhancements

• feat: add collect schema to interchange dfs (#1646)
• feat: support std and var with ddof !=1 in pandas-like group by (#1645)
• feat: add DataFrame and LazyFrame explode method (#1542)

🐞 Bug fixes

• fix: Make compatible with latest cuDF release (#1640)

📖 Documentation

• docs: Note that maintains_order has no effect (but keep around for backwards-compatibility) (#1643)
• docs: fix typing example (#1637)
• docs: Use relative paths (#1636)
• docs: Remove warnings when building docs (#1631)
• docs: returns and arguments documentation for lazyframe class (#1630)
• docs: null handling (#1624)

🛠️ Other improvements

• chore: Update pyproject.toml (#1642)
• chore: register kwargs for CompliantExpr (#1614)
• fix: exclude protocols in api completeness script (#1635)
• test: not-so-old-versions, pretty-old-versions, nightlies (#1626)

Thank you to all our contributors for making this release possible!
@AlessandroMiola, @DeaMariaLeon, @Dhanunjaya-Elluri, @FBruzzesi, @MarcoGorelli, @marenwestermann and @marvinl803

Narwhals v1.19.0

Changes

🚀 Performance improvements

• perf: streamline pyarrow and pandas group by agg (#1621)

✨ Enhancements

• feat: add Series|Expr.rolling_var and Series|Expr.rolling_std (#1451)
• fix: Add support for pandas cumulative operations with over (#1565)
• feat: add var to Expr and Series (#1603)

🐞 Bug fixes

• fix: nw.col('a').is_in(df['b']) was raising (#1616)
• fix: pandas and pyarrow were raising for repeated aggregations involving the same root name and the same aggregation function (#1613)

📖 Documentation

• docs: more args and returns documentation in DataFrame class (#1600)
• docs: make docstring examples function names more descriptive in functions.py (#1602)
• docs: improve DataFrame, LazyFrame and Series docstrings (#1622)

🛠️ Other improvements

• ci: unpin scikit-learn in scikit-lego test (#1611)
• ci: Speed up tests in local development (#1608)
• test: downstream test for tea-tasting (#1605)
• test: minimum versions (#1617)

Thank you to all our contributors for making this release possible!
@ClaudioSalvatoreArcidiacono, @DeaMariaLeon, @Dhanunjaya-Elluri, @FBruzzesi, @Machele-codez, @MarcoGorelli, @e10v, @marenwestermann and @skritsotalakis

Narwhals v1.18.4

Changes

✨ Enhancements

• feat: add Series and Expr arg_min & arg_max (#1529)

🐞 Bug fixes

• fix: allow np.scalar to be used in Series.getitem (#1515)
• fix: fix pyarrow len aggregation behaviour for depth-1 exprs (#1589)

📖 Documentation

• docs: document arguments and returns in DataFrame class (#1594)
• docs: add tea-tasting to ecosystem (#1593)
• docs: Correct small error in IntoDataFrameT and IntoSeriesT (#1591)
• docs: add docstring example for Array in narwhals.dtypes (#1576)

🛠️ Other improvements

• test: xfail cudf argmin / argmax (#1599)
• chore: use set_axis in maybe_set_index (#1598)
• test: fixup more cuDF xfails (#1596)
• test: xfail test_group_by_shift_raises for cudf (#1595)
• chore: Add some Compliant Protocols (#1522)

Thank you to all our contributors for making this release possible!
@AlessandroMiola, @DeaMariaLeon, @Dhanunjaya-Elluri, @MarcoGorelli, @Nathan-Bransby-NMT, @e10v, @marenwestermann and @thevro

Narwhals v1.18.3

Changes

• release: Bump version to 1.18.2 (#1582)

✨ Enhancements

• feat/fix: Improve error message when trying to do unsupported group-by aggregation, and raise instead of giving inconsistent results (#1584)

🛠️ Other improvements

• refactor: PandasLikeExpr repr and init (#1585)

Thank you to all our contributors for making this release possible!
@MarcoGorelli, @anopsy and @camriddell