●Change8

Migrating to Polars py-1.31.0-beta.1

Version py-1.31.0-beta.1 introduces 1 breaking change. This guide details how to update your code.

Released: 6/14/2025

1
Breaking Changes
2
Migration Steps
35
Affected Symbols

⚠️ Check Your Code

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

scan_parquettruncatelist.evalarg_sort_bywrite_csvpl.lenscan_csvstr.zfillpl.Expr.__array_ufunc__Agg::CountrenameselectParquetFieldOverwritesfinish_callbacksearch_sortedcum_sumgroup_bysortrolling_min/maxarg_maxindex_ofBooleanChunkedscan_delta()collect(background=True)collect_concurrently()register_io_sourcepropagate_nullssink_ipcDataType.is_rolling_mean<f32>map_elementsint_rangesDataTypeExprExpr::RenameAliasassert_series_equal

Breaking Changes

●Issue #1

Removed the old streaming engine. Users relying on the previous streaming implementation must update their code to use the new engine.

Migration Steps

  1. 1
    If you were using the old streaming engine, update your code to use the new streaming implementation.
  2. 2
    Replace usage of `allow_missing_columns` in `scan_parquet` with the `missing_columns` parameter.

Release Summary

This release removes the old streaming engine, introduces DataType expressions and Iceberg positional delete support, and includes numerous performance optimizations and bug fixes across various components.

Need More Details?

View the full release notes and all changes for Polars py-1.31.0-beta.1.

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