polars.Series.str.splitn#

Series.str.splitn(by: IntoExpr, n: int) → Series[source]#

Split the string by a substring, restricted to returning at most n items.

If the number of possible splits is less than n-1, the remaining field elements will be null. If the number of possible splits is n-1 or greater, the last (nth) substring will contain the remainder of the string.

Parameters:

by: Substring to split by.
n: Max number of items to return.

Returns:

Series: Series of data type Struct with fields of data type String.

Examples

>>> df = pl.DataFrame({"s": ["foo bar", None, "foo-bar", "foo bar baz"]})
>>> df["s"].str.splitn(" ", 2).alias("fields")
shape: (4,)
Series: 'fields' [struct[2]]
[
        {"foo","bar"}
        {null,null}
        {"foo-bar",null}
        {"foo","bar baz"}
]

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

>>> (
...     df["s"]
...     .str.splitn(" ", 2)
...     .struct.rename_fields(["first_part", "second_part"])
...     .alias("fields")
...     .to_frame()
...     .unnest("fields")
... )
shape: (4, 2)
┌────────────┬─────────────┐
│ first_part ┆ second_part │
│ ---        ┆ ---         │
│ str        ┆ str         │
╞════════════╪═════════════╡
│ foo        ┆ bar         │
│ null       ┆ null        │
│ foo-bar    ┆ null        │
│ foo        ┆ bar baz     │
└────────────┴─────────────┘