pl.Expr.explode()
from PolarsのExpression
listを行に変換できる
https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.Expr.explode.html
例 ref
code:py
out = weather.with_columns(pl.col("temperatures").str.split(" ")).explode("temperatures")
code:before
┌───────────┬──────────────────────┐
│ station ┆ temperatures │
│ --- ┆ --- │
│ str ┆ liststr │
╞═══════════╪══════════════════════╡
│ Station 1 ┆ "20", "5", … "20" │
│ Station 2 ┆ "18", "8", … "40" │
│ Station 3 ┆ "19", "24", … "22" │
│ Station 4 ┆ "E2", "E0", … "6" │
│ Station 5 ┆ "14", "8", … "E1" │
└───────────┴──────────────────────┘
code:after
┌───────────┬──────────────┐
│ station ┆ temperatures │
│ --- ┆ --- │
│ str ┆ str │
╞═══════════╪══════════════╡
│ Station 1 ┆ 20 │
│ Station 1 ┆ 5 │
│ Station 1 ┆ 5 │
│ Station 1 ┆ E1 │
│ Station 1 ┆ 7 │
│ … ┆ … │
│ Station 5 ┆ E0 │
│ Station 5 ┆ 16 │
│ Station 5 ┆ 22 │
│ Station 5 ┆ 24 │
│ Station 5 ┆ E1 │
└───────────┴──────────────┘