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)
      ╭─────┬───────────┬─────╮
      │ ham ┆ hamburger ┆ foo │
      │ --- ┆ --- ┆ --- │
      │ i64 ┆ i64 ┆ i64 │
      ╞═════╪═══════════╪═════╡
      │ 1 ┆ 11 ┆ 3 │
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 2 ┆ 22 ┆ 2 │
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 3 ┆ 33 ┆ 1 │
      ╰─────┴───────────┴─────╯
      > df.select(col("^ham.*$"))
      shape: (3, 2)
      ╭─────┬───────────╮
      │ ham ┆ hamburger │
      │ --- ┆ --- │
      │ i64 ┆ i64 │
      ╞═════╪═══════════╡
      │ 1 ┆ 11 │
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┤
      │ 2 ┆ 22 │
      ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌┤
      │ 3 ┆ 33 │
      ╰─────┴───────────╯
      > df.select(col("*").exclude("ham"))
      shape: (3, 2)
      ╭───────────┬─────╮
      │ hamburger ┆ foo │
      │ --- ┆ --- │
      │ i64 ┆ i64 │
      ╞═══════════╪═════╡
      │ 11 ┆ 3 │
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 22 ┆ 2 │
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 33 ┆ 1 │
      ╰───────────┴─────╯
      > df.select(col(["hamburger", "foo"])
      shape: (3, 2)
      ╭───────────┬─────╮
      │ hamburger ┆ foo │
      │ --- ┆ --- │
      │ i64 ┆ i64 │
      ╞═══════════╪═════╡
      │ 11 ┆ 3 │
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 22 ┆ 2 │
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 33 ┆ 1 │
      ╰───────────┴─────╯
      > df.select(col(pl.Series(["hamburger", "foo"]))
      shape: (3, 2)
      ╭───────────┬─────╮
      │ hamburger ┆ foo │
      │ --- ┆ --- │
      │ i64 ┆ i64 │
      ╞═══════════╪═════╡
      │ 11 ┆ 3 │
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 22 ┆ 2 │
      ├╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌┤
      │ 33 ┆ 1 │
      ╰───────────┴─────╯