lazyframe

Joins a lazy frame with other lazy frame.

This command requires a plugin

The polars join command resides in the polars plugin. To use this command, you must install and register nu_plugin_polars. See the Plugins chapter in the book for more information.

Signature

> polars join {flags} (other) (left_on) (right_on)

Flags

• --inner, -i: inner joining between lazyframes (default)
• --left, -l: left join between lazyframes
• --full, -f: full join between lazyframes
• --cross, -c: cross join between lazyframes
• --suffix, -s {string}: Suffix to use on columns with same name

Parameters

• other: LazyFrame to join with
• left_on: Left column(s) to join on
• right_on: Right column(s) to join on

Input/output types:

input	output
any	any

Examples

Join two lazy dataframes

> let df_a = ([[a b c];[1 "a" 0] [2 "b" 1] [1 "c" 2] [1 "c" 3]] | polars into-lazy);
    let df_b = ([["foo" "bar" "ham"];[1 "a" "let"] [2 "c" "var"] [3 "c" "const"]] | polars into-lazy);
    $df_a | polars join $df_b a foo | polars collect
╭───┬───┬───┬───┬─────┬─────╮
│ # │ a │ b │ c │ bar │ ham │
├───┼───┼───┼───┼─────┼─────┤
│ 0 │ 1 │ a │ 0 │ a   │ let │
│ 1 │ 2 │ b │ 1 │ c   │ var │
│ 2 │ 1 │ c │ 2 │ a   │ let │
│ 3 │ 1 │ c │ 3 │ a   │ let │
╰───┴───┴───┴───┴─────┴─────╯

Join one eager dataframe with a lazy dataframe

> let df_a = ([[a b c];[1 "a" 0] [2 "b" 1] [1 "c" 2] [1 "c" 3]] | polars into-df);
    let df_b = ([["foo" "bar" "ham"];[1 "a" "let"] [2 "c" "var"] [3 "c" "const"]] | polars into-lazy);
    $df_a | polars join $df_b a foo
╭───┬───┬───┬───┬─────┬─────╮
│ # │ a │ b │ c │ bar │ ham │
├───┼───┼───┼───┼─────┼─────┤
│ 0 │ 1 │ a │ 0 │ a   │ let │
│ 1 │ 2 │ b │ 1 │ c   │ var │
│ 2 │ 1 │ c │ 2 │ a   │ let │
│ 3 │ 1 │ c │ 3 │ a   │ let │
╰───┴───┴───┴───┴─────┴─────╯