Python Polars 0.18.0

🏆 Highlights

• Rename list namespace accesor from .arr to .list (#8999)

⚠️ Breaking changes

• propagate null in equality comparisons (#9053)
• formalize implode -> explode relation (#9038)
• Drop subclassing support for DataFrame/LazyFrame (#9008)
• consistently return list of date/datetime from lazy date_range (#8513)
• Default date_range/ones/zeros to eager=False (#9007)
• Rename list namespace accesor from .arr to .list (#8999)
• disallow time zones other than those in zoneinfo.available_timezones() (#8993)
• remove window expression magic (#8992)
• raise error when sorted flag not set (#8994)
• Drop subclassing support for GroupBy (#7746)
• in Series constructor, if inputs are time-zone-aware datetimes, convert to UTC (#8881)
• parse offset-naive date time strings as Timestamp(time_unit), offset-aware datetime strings as Timestamp(time_unit, "UTC"), and remove the utc argument (#8714)
• Remove deprecated tz_aware argument (#8696)

🚀 Performance improvements

• speed up write_csv for time-zone-aware columns (#9093)
• parallelize rolling_window group materialization (#9095)
• elide hot loop in hash joins (#9075)

✨ Enhancements

• conversion from Utf8 to Decimal. (#9090)
• default to checking sortedness in groupby_rolling… (#9063)
• propagate null in equality comparisons (#9053)
• warn if constructing Series with time-zone-aware datetimes (#9058)
• implement apply for rolling/dynamic_groupby (#9049)
• Support more data types in lazy repeat (#9046)
• implement strategy=nearest for join_asof (#9024)
• arr.sum expression (#9041)
• formalize implode -> explode relation (#9038)
• add array namespace and min/max expression (#9032)
• improve error message on row-wise overflow (#9021)
• properly apply slice at UNION level (#9018)
• consistently return list of date/datetime from lazy date_range (#8513)
• Default date_range/ones/zeros to eager=False (#9007)
• disallow time zones other than those in zoneinfo.available_timezones() (#8993)
• raise error when sorted flag not set (#8994)
• in Series constructor, if inputs are time-zone-aware datetimes, convert to UTC (#8881)
• parse offset-naive date time strings as Timestamp(time_unit), offset-aware datetime strings as Timestamp(time_unit, "UTC"), and remove the utc argument (#8714)

🐞 Bug fixes

• rolling_groupy was returning incorrect results when offset was positive (#9082)
• don't underflow on list.tail (#9089)
• fix null/empty in List::take_unchecked (#9074)
• repeat by (#9023)
• raise in to_datetime/strptime if format contains hour but not minute directive (#9044)
• Order of pl.Array arguments in docstring (#9059)
• propagate nulls in broadcasting of order comparisons (#9050)
• Improve read_parquet missing column error message (#8961)
• fix apply with passed date/datetime return_dtype (#9035)
• respect inner type in Array construction (#9020)
• raise error on invalid aggregation (#9013)
• fix fused arithmetic in window functions (#9012)
• don't allow silent init of Series declared as int/temporal with floating point values (#9004)
• deprecate time_unit property from Series (#8990)

🛠️ Other improvements

• Improve expression parsing utils (#9094)
• Refactor expression input parsing util (#9085)
• Organize "as_datatype" functions (#9080)
• Change eager path for repeat (#9048)
• Clean up arange/date_range/time_range (#9027)
• Drop subclassing support for DataFrame/LazyFrame (#9008)
• minor SQLContext docstring cleanups (#9005)
• Rename list namespace accesor from .arr to .list (#8999)
• remove window expression magic (#8992)
• Drop subclassing support for GroupBy (#7746)
• refactor!(python): Remove old deprecated functionality (#8995)
• Remove deprecated tz_aware argument (#8696)

Thank you to all our contributors for making this release possible!
@CloseChoice, @MarcoGorelli, @alexander-beedie, @charliegallop, @jonashaag, @mcrumiller, @raymead, @ritchie46, @sorhawell, @stinodego, @tim-habitat and @universalmind303