nodejs-polars
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    Function col

    • A column in a DataFrame. Can be used to select:

      • a single column by name
      • all columns by using a wildcard "*"
      • column by regular expression if the regex starts with ^ and ends with $

      Parameters

      Returns pl.Expr

      > df = pl.DataFrame({
      > "ham": [1, 2, 3],
      > "hamburger": [11, 22, 33],
      > "foo": [3, 2, 1]})
      > df.select(col("foo"))
      shape: (3, 1)
      ╭─────╮
      foo
      │ --- │
      i64
      ╞═════╡
      3
      ├╌╌╌╌╌┤
      2
      ├╌╌╌╌╌┤
      1
      ╰─────╯
      > df.select(col("*"))
      shape: (3, 3)
      ╭─────┬───────────┬─────╮
      hamhamburgerfoo
      │ --- ┆ --- ┆ --- │
      i64i64i64
      ╞═════╪═══════════╪═════╡
      1113
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      2222
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      3331
      ╰─────┴───────────┴─────╯
      > df.select(col("^ham.*$"))
      shape: (3, 2)
      ╭─────┬───────────╮
      hamhamburger
      │ --- ┆ --- │
      i64i64
      ╞═════╪═══════════╡
      111
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┤
      222
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┤
      333
      ╰─────┴───────────╯
      > df.select(col("*").exclude("ham"))
      shape: (3, 2)
      ╭───────────┬─────╮
      hamburgerfoo
      │ --- ┆ --- │
      i64i64
      ╞═══════════╪═════╡
      113
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      222
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      331
      ╰───────────┴─────╯
      > df.select(col(["hamburger", "foo"])
      shape: (3, 2)
      ╭───────────┬─────╮
      hamburgerfoo
      │ --- ┆ --- │
      i64i64
      ╞═══════════╪═════╡
      113
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      222
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      331
      ╰───────────┴─────╯
      > df.select(col(pl.Series(["hamburger", "foo"]))
      shape: (3, 2)
      ╭───────────┬─────╮
      hamburgerfoo
      │ --- ┆ --- │
      i64i64
      ╞═══════════╪═════╡
      113
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      222
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      331
      ╰───────────┴─────╯