Select all struct columns

Source code

Description

Usage

cs__struct()

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$array(): Select all array columns.
• cs$nested(): Select all nested columns.

Examples

library("polars")

df <- pl$DataFrame(
  foo = data.frame(a = c("xx", "x"), b = c("yy", "y")),
  bar = data.frame(a = c(123, 456), b = c(789, 101)),
  baz = c(2.0, 5.5),
)

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

#> shape: (2, 2)
#> ┌─────────────┬───────────────┐
#> │ foo         ┆ bar           │
#> │ ---         ┆ ---           │
#> │ struct[2]   ┆ struct[2]     │
#> ╞═════════════╪═══════════════╡
#> │ {"xx","yy"} ┆ {123.0,789.0} │
#> │ {"x","y"}   ┆ {456.0,101.0} │
#> └─────────────┴───────────────┘

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

#> shape: (2, 1)
#> ┌─────┐
#> │ baz │
#> │ --- │
#> │ f64 │
#> ╞═════╡
#> │ 2.0 │
#> │ 5.5 │
#> └─────┘

# If you want to select specific struct columns,
# you can use the `by_dtype()` selector:
df$select(cs$by_dtype(pl$Struct(
  a = pl$String,
  b = pl$String
)))

#> shape: (2, 1)
#> ┌─────────────┐
#> │ foo         │
#> │ ---         │
#> │ struct[2]   │
#> ╞═════════════╡
#> │ {"xx","yy"} │
#> │ {"x","y"}   │
#> └─────────────┘