diff --git a/py-polars/polars/dataframe/frame.py b/py-polars/polars/dataframe/frame.py index 2d8710b9f431..83e55cfe64b3 100644 --- a/py-polars/polars/dataframe/frame.py +++ b/py-polars/polars/dataframe/frame.py @@ -7103,21 +7103,25 @@ def join_where( suffix: str = "_right", ) -> DataFrame: """ - Perform a join based on one or multiple equality predicates. + Perform a join based on one or multiple (in)equality predicates. + + This performs an inner join, so only rows where all predicates are true + are included in the result, and a row from either DataFrame may be included + multiple times in the result. + + .. note:: + The row order of the input DataFrames is not preserved. .. warning:: This functionality is experimental. It may be changed at any point without it being considered a breaking change. - A row from this table may be included in zero or multiple rows in the result, - and the relative order of rows may differ between the input and output tables. - Parameters ---------- other DataFrame to join with. *predicates - (In)Equality condition to join the two table on. + (In)Equality condition to join the two tables on. When a column name occurs in both tables, the proper suffix must be applied in the predicate. suffix diff --git a/py-polars/polars/lazyframe/frame.py b/py-polars/polars/lazyframe/frame.py index ec329898441a..d50c2867dd24 100644 --- a/py-polars/polars/lazyframe/frame.py +++ b/py-polars/polars/lazyframe/frame.py @@ -4571,8 +4571,12 @@ def join_where( """ Perform a join based on one or multiple (in)equality predicates. - A row from this table may be included in zero or multiple rows in the result, - and the relative order of rows may differ between the input and output tables. + This performs an inner join, so only rows where all predicates are true + are included in the result, and a row from either DataFrame may be included + multiple times in the result. + + .. note:: + The row order of the input DataFrames is not preserved. .. warning:: This functionality is experimental. It may be @@ -4583,7 +4587,7 @@ def join_where( other DataFrame to join with. *predicates - (In)Equality condition to join the two table on. + (In)Equality condition to join the two tables on. When a column name occurs in both tables, the proper suffix must be applied in the predicate. suffix