●Change8

Migrating to Polars py-1.33.0-beta.1

Version py-1.33.0-beta.1 introduces 1 breaking change. This guide details how to update your code.

Released: 8/28/2025

1
Breaking Changes
1
Migration Steps
38
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

pl.Expr.logpl.Series.shiftwrite_parquetExpr.diffpl.LazyFrame.pipe_with_schemaBytecodeParsercum_*peak\_{min,max}DataFrame.map_columnsDecimalslicefilter(lit(True))gathermap_groupsLazyGroupBy.{head,tail}polars cloud CSV scancategorical columns IO pluginconcat_listRolling_meanis_in predicateread_databasePyCategoriesto_mutable_slicePyO3 extension typestop_ksort_bygroup_by_dynamicto_arrowjoin_wheredivfrom_reprgroup_bypartition_byfoldreduceExpr.meta.output_namepl.Datemean

Breaking Changes

●Issue #1

Eager Exprs have been removed, deprecated, or changed to be lazy compatible. Users relying on eager evaluation of expressions that are now lazy may see changes in behavior or errors if the expression context is no longer implicitly eager.

Migration Steps

  1. 1
    Review code that relied on eager evaluation of expressions, as many have been made lazy compatible, which might change execution context.

Release Summary

This release focuses heavily on performance improvements by lowering various operations to the streaming engine and enhancing lazy evaluation capabilities, alongside numerous bug fixes and the removal of eager expression behavior.

Need More Details?

View the full release notes and all changes for Polars py-1.33.0-beta.1.

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