pola-rs/polars py-0.20.31

Python Polars 0.20.31

on GitHub

⚠️ Deprecations

• Rename dtypes parameter to schema_overrides for read_csv/scan_csv/read_csv_batched (#16628)
• Deprecate nulls_last/maintain_order/multithreaded parameters for top_k methods (#16597)
• Rename SQLContext "eager_execution" param to "eager" (#16595)
• Rename Series.equals parameter strict to check_dtypes and rename assertion utils parameter check_dtype to check_dtypes (#16573)
• Add DataFrame.serialize/deserialize (#16545)
• Deprecate str.explode in favor of str.split("").explode() (#16508)
• Deprecate default coalesce behavior of left join (#16532)

🚀 Performance improvements

• make truncate 4x faster in simple cases (#16615)
• Cache arena's (and conversion) in SQL context (#16566)
• Partial schema cache. (#16549)

✨ Enhancements

• Support per-column nulls_last on sort operations (#16639)
• Initial support for SQL ARRAY literals and the UNNEST table function (#16330)
• Don't allow struct.with_fields in grouping (#16629)
• improve support for user-defined functions that return scalars (#16556)
• Add SQL support for TRY_CAST function (#16589)
• Add top-level pl.sql function (#16528)
• Expose temporal function expression ops to expr ir (#16546)
• Add DataFrame.serialize/deserialize (#16545)
• check if by column is sorted, rather than just checking sorted flag, in group_by_dynamic, upsample, and rolling (#16494)

🐞 Bug fixes

• Potentially deal with empty range (#16650)
• Use of SQL ORDER BY should not cause reordering of SELECT cols (#16579)
• ensure df in empty parquet (#16621)
• Fix Array constructor when inner type is another Array (#16622)
• Fix parsing of shape in Array constructor and deprecate width parameter (#16567)
• Crash using empty Series in LazyFrame.select() (#16592)
• improve support for user-defined functions that return scalars (#16556)
• Resolve multiple SQL JOIN issues (#16507)
• Project last column if count query (#16569)
• Properly split struct columns (#16563)
• Ensure strict chunking in chunked partitioned group by (#16561)
• Error selecting columns after non-coalesced join (multiple join keys) (#16559)
• Don't panic on hashing nested list types (#16555)
• Crash selecting columns after non-coalesced join (#16541)
• Fix group gather of single literal (#16539)
• throw an invalid operation exception on performing a sum over a list of strs (#16521)
• Fix DataFrame.__getitem__ for empty list input - df[[]] (#16520)
• Fix issue in DataFrame.__getitem__ with 2 column inputs (#16517)

📖 Documentation

• Overview of available SQL functions (#16268)
• Update filter description to clarify that null evaluations are removed (#16632)
• Include warning in docstrings that accessing LazyFrame properties may be expensive (#16618)
• Add a few versionadded tags, and add is_column_selection to the Expr meta docs (#16590)
• Fix bullet points not rendering correctly in DataFrame.join docstring (#16576)
• Remove erroneous implode reference from the user guide section on window functions (#16544)

📦 Build system

• Run cargo update (#16574)

🛠️ Other improvements

• Add test for 16642 (#16646)
• Remove duplicate tag in CODEOWNERS (#16625)
• Update dprint hook versions and enable JSON linting (#16611)
• Fewer typing.no_type_check (#16497)

Thank you to all our contributors for making this release possible!
@MarcoGorelli, @alexander-beedie, @coastalwhite, @hattajr, @itamarst, @mcrumiller, @nameexhaustion, @r-brink, @ritchie46, @stinodego, @twoertwein and @wence-