polars.Expr.str.split_exact#

Expr.str.split_exact(by: IntoExpr, n: int, *, inclusive: bool = False) → Expr[source]#

Split the string by a substring using n splits.

Results in a struct of n+1 fields.

If it cannot make n splits, the remaining field elements will be null.

Parameters:

by: Substring to split by.
n: Number of splits to make.
inclusive: If True, include the split character/string in the results.

Returns:

Expr: Expression of data type Struct with fields of data type Utf8.

Examples

>>> df = pl.DataFrame({"x": ["a_1", None, "c", "d_4"]})
>>> df.with_columns(
...     extracted=pl.col("x").str.split_exact("_", 1).alias("fields"),
... )
shape: (4, 2)
┌──────┬─────────────┐
│ x    ┆ extracted   │
│ ---  ┆ ---         │
│ str  ┆ struct[2]   │
╞══════╪═════════════╡
│ a_1  ┆ {"a","1"}   │
│ null ┆ {null,null} │
│ c    ┆ {"c",null}  │
│ d_4  ┆ {"d","4"}   │
└──────┴─────────────┘

Split string values in column x in exactly 2 parts and assign each part to a new column.

>>> df.with_columns(
...     [
...         pl.col("x")
...         .str.split_exact("_", 1)
...         .struct.rename_fields(["first_part", "second_part"])
...         .alias("fields"),
...     ]
... ).unnest("fields")
shape: (4, 3)
┌──────┬────────────┬─────────────┐
│ x    ┆ first_part ┆ second_part │
│ ---  ┆ ---        ┆ ---         │
│ str  ┆ str        ┆ str         │
╞══════╪════════════╪═════════════╡
│ a_1  ┆ a          ┆ 1           │
│ null ┆ null       ┆ null        │
│ c    ┆ c          ┆ null        │
│ d_4  ┆ d          ┆ 4           │
└──────┴────────────┴─────────────┘