nushell/crates/nu_plugin_polars
Darren Schroeder baf86dfb0e
tweak polars join for better cross joins (#14586)
# Description

closes #14585

This PR tries to make `polars join --cross` work better. Example taken
from
https://docs.pola.rs/user-guide/transformations/joins/#cartesian-product

### Before
```nushell
❯ let tokens = [[monopoly_token]; [hat] [shoe] [boat]] | polars into-df
❯ let players = [[name, cash]; [Alice, 78] [Bob, 135]] | polars into-df
❯ $players | polars into-lazy | polars select (polars col name) | polars join --cross $tokens | polars collect
Error: nu::parser::missing_positional

  × Missing required positional argument.
   ╭─[entry #3:1:92]
 1 │ $players | polars into-lazy | polars select (polars col name) | polars join --cross $tokens
   ╰────
  help: Usage: polars join {flags} <other> <left_on> <right_on> . Use `--help` for more information.
```
### After
```nushell
❯ let players = [[name, cash]; [Alice, 78] [Bob, 135]] | polars into-df
❯ let tokens = [[monopoly_token]; [hat] [shoe] [boat]] | polars into-df
❯ $players | polars into-lazy | polars select (polars col name) | polars join --cross $tokens | polars collect
╭─#─┬─name──┬─monopoly_token─╮
│ 0 │ Alice │ hat            │
│ 1 │ Alice │ shoe           │
│ 2 │ Alice │ boat           │
│ 3 │ Bob   │ hat            │
│ 4 │ Bob   │ shoe           │
│ 5 │ Bob   │ boat           │
╰─#─┴─name──┴─monopoly_token─╯
```
Other examples
```nushell
❯ 1..3 | polars into-df | polars join --cross (4..6 | polars into-df)
╭─#─┬─0─┬─0_x─╮
│ 0 │ 1 │   4 │
│ 1 │ 1 │   5 │
│ 2 │ 1 │   6 │
│ 3 │ 2 │   4 │
│ 4 │ 2 │   5 │
│ 5 │ 2 │   6 │
│ 6 │ 3 │   4 │
│ 7 │ 3 │   5 │
│ 8 │ 3 │   6 │
╰─#─┴─0─┴─0_x─╯
❯ 1..3 | each {|x| {x: $x}} | polars into-df | polars join --cross (4..6 | each {|y| {y: $y}} | polars into-df) x y
╭─#─┬─x─┬─y─╮
│ 0 │ 1 │ 4 │
│ 1 │ 1 │ 5 │
│ 2 │ 1 │ 6 │
│ 3 │ 2 │ 4 │
│ 4 │ 2 │ 5 │
│ 5 │ 2 │ 6 │
│ 6 │ 3 │ 4 │
│ 7 │ 3 │ 5 │
│ 8 │ 3 │ 6 │
╰─#─┴─x─┴─y─╯
```
/cc @ayax79 
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2024-12-14 21:58:47 -06:00
..
src tweak polars join for better cross joins (#14586) 2024-12-14 21:58:47 -06:00
Cargo.toml Bump indexmap from 2.6.0 to 2.7.0 (#14505) 2024-12-04 09:57:05 +08:00
LICENSE Move dataframes support to a plugin (#12220) 2024-04-09 19:31:43 -05:00