Method: Polars::Functions#concat_str

Defined in:
lib/polars/functions/as_datatype.rb

#concat_str(exprs, *more_exprs, separator: "", ignore_nulls: false) ⇒ Expr

Horizontally concat Utf8 Series in linear time. Non-Utf8 columns are cast to Utf8.

Examples:

df = Polars::DataFrame.new(
  {
    "a" => [1, 2, 3],
    "b" => ["dogs", "cats", nil],
    "c" => ["play", "swim", "walk"]
  }
)
df.with_columns(
  [
    Polars.concat_str(
      [
        Polars.col("a") * 2,
        Polars.col("b"),
        Polars.col("c")
      ],
      separator: " "
    ).alias("full_sentence")
  ]
)
# =>
# shape: (3, 4)
# ┌─────┬──────┬──────┬───────────────┐
# │ a   ┆ b    ┆ c    ┆ full_sentence │
# │ --- ┆ ---  ┆ ---  ┆ ---           │
# │ i64 ┆ str  ┆ str  ┆ str           │
# ╞═════╪══════╪══════╪═══════════════╡
# │ 1   ┆ dogs ┆ play ┆ 2 dogs play   │
# │ 2   ┆ cats ┆ swim ┆ 4 cats swim   │
# │ 3   ┆ null ┆ walk ┆ null          │
# └─────┴──────┴──────┴───────────────┘

Parameters:

  • exprs (Object) —

    Columns to concat into a Utf8 Series.

  • more_exprs (Array) —

    Additional columns to concatenate into a single string column, specified as positional arguments.

  • separator (String) (defaults to: "") —

    String value that will be used to separate the values.

  • ignore_nulls (Boolean) (defaults to: false) —

    Ignore null values (default).

Returns:



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# File 'lib/polars/functions/as_datatype.rb', line 544

def concat_str(exprs, *more_exprs, separator: "", ignore_nulls: false)
  exprs = Utils.parse_into_list_of_expressions(exprs, *more_exprs)
  Utils.wrap_expr(Plr.concat_str(exprs, separator, ignore_nulls))
end