load nested JSON data with polars without using explode

[kolibril13]

Description

I am currently using this snippet to load and explode JSON objects with polars.
My question: Is there a better way to load my desired data format without the explode call?

import polars as pl
from io import StringIO

json_file = StringIO(
    """
{
  "Star": [
    [58.2136, 91.8819, 0.0],
    [58.1961, 92.215, 0.0]
  ],
  "Is_Visible": [
    [true],
    [false]
  ],
  "Intensity": [
    [10],
    [20]
  ]
}
"""
)

df = pl.read_json(json_file)
columns_to_explode = [col for col in df.columns if df[col].dtype == pl.List(pl.List)]
df2 = df.explode(columns_to_explode)
print(df)
print(df2)

shape: (1, 3)
┌─────────────────────────────────┬───────────────────┬─────────────────┐
│ Star                            ┆ Is_Visible        ┆ Intensity       │
│ ---                             ┆ ---               ┆ ---             │
│ list[list[f64]]                 ┆ list[list[bool]]  ┆ list[list[i64]] │
╞═════════════════════════════════╪═══════════════════╪═════════════════╡
│ [[58.2136, 91.8819, 0.0], [58.… ┆ [[true], [false]] ┆ [[10], [20]]    │
└─────────────────────────────────┴───────────────────┴─────────────────┘
shape: (2, 3)
┌─────────────────────────┬────────────┬───────────┐
│ Star                    ┆ Is_Visible ┆ Intensity │
│ ---                     ┆ ---        ┆ ---       │
│ list[f64]               ┆ list[bool] ┆ list[i64] │
╞═════════════════════════╪════════════╪═══════════╡
│ [58.2136, 91.8819, 0.0] ┆ [true]     ┆ [10]      │
│ [58.1961, 92.215, 0.0]  ┆ [false]    ┆ [20]      │
└─────────────────────────┴────────────┴───────────┘

[ritchie46]

That's asking to ignore the json schema, or at least interpret it differently, which is not something I am keen on. What's wrong with exploding the data? I don't think compute shouldn't be pushed down in the readers (at least kept to a minimum)..