Select all nested columns

Source code

Description

A nested column is a list, array or struct.

Usage

cs__nested()

Value

A Polars selector

See Also

• cs for the documentation on operators supported by selectors.
• cs$by_dtype(): Select all columns matching the given dtype(s).
• cs$list(): Select all list columns.
• cs$array(): Select all array columns.
• cs$struct(): Select all struct columns.

Examples

library("polars")

df <- pl$DataFrame(
  foo = data.frame(a = c("xx", "x"), b = c("yy", "y")),
  bar = c(123, 456),
  baz = c(2, 5.5),
  wow = list(c(1, 2), c(3)),
)

# Select all nested columns:
df$select(cs$nested())

#> shape: (2, 2)
#> ┌─────────────┬────────────┐
#> │ foo         ┆ wow        │
#> │ ---         ┆ ---        │
#> │ struct[2]   ┆ list[f64]  │
#> ╞═════════════╪════════════╡
#> │ {"xx","yy"} ┆ [1.0, 2.0] │
#> │ {"x","y"}   ┆ [3.0]      │
#> └─────────────┴────────────┘

# Select all columns except for those that are nested:
df$select(!cs$nested())

#> shape: (2, 2)
#> ┌───────┬─────┐
#> │ bar   ┆ baz │
#> │ ---   ┆ --- │
#> │ f64   ┆ f64 │
#> ╞═══════╪═════╡
#> │ 123.0 ┆ 2.0 │
#> │ 456.0 ┆ 5.5 │
#> └───────┴─────┘