polars.Expr.rle#
- Expr.rle() Expr [source]#
Compress the column data using run-length encoding.
Run-length encoding (RLE) encodes data by storing each run of identical values as a single value and its length.
- Returns:
- Expr
Expression of data type
Struct
with fieldslen
of data typeUInt32
andvalue
of the original data type.
See also
Examples
>>> df = pl.DataFrame({"a": [1, 1, 2, 1, None, 1, 3, 3]}) >>> df.select(pl.col("a").rle()).unnest("a") shape: (6, 2) ┌─────┬───────┐ │ len ┆ value │ │ --- ┆ --- │ │ u32 ┆ i64 │ ╞═════╪═══════╡ │ 2 ┆ 1 │ │ 1 ┆ 2 │ │ 1 ┆ 1 │ │ 1 ┆ null │ │ 1 ┆ 1 │ │ 2 ┆ 3 │ └─────┴───────┘