polars.Expr.str.extract_many#

Expr.str.extract_many( patterns: IntoExpr, *, ascii_case_insensitive: bool = False, overlapping: bool = False, ) → Expr[source]#

Use the Aho-Corasick algorithm to extract many matches.

Parameters:

patterns: String patterns to search.
ascii_case_insensitive: Enable ASCII-aware case-insensitive matching. When this option is enabled, searching will be performed without respect to case for ASCII letters (a-z and A-Z) only.
overlapping: Whether matches may overlap.

Notes

This method supports matching on string literals only, and does not support regular expression matching.

Examples

>>> _ = pl.Config.set_fmt_str_lengths(100)
>>> df = pl.DataFrame({"values": ["discontent"]})
>>> patterns = ["winter", "disco", "onte", "discontent"]
>>> df.with_columns(
...     pl.col("values")
...     .str.extract_many(patterns, overlapping=False)
...     .alias("matches"),
...     pl.col("values")
...     .str.extract_many(patterns, overlapping=True)
...     .alias("matches_overlapping"),
... )
shape: (1, 3)
┌────────────┬───────────┬─────────────────────────────────┐
│ values     ┆ matches   ┆ matches_overlapping             │
│ ---        ┆ ---       ┆ ---                             │
│ str        ┆ list[str] ┆ list[str]                       │
╞════════════╪═══════════╪═════════════════════════════════╡
│ discontent ┆ ["disco"] ┆ ["disco", "onte", "discontent"] │
└────────────┴───────────┴─────────────────────────────────┘
>>> df = pl.DataFrame(
...     {
...         "values": ["discontent", "rhapsody"],
...         "patterns": [
...             ["winter", "disco", "onte", "discontent"],
...             ["rhap", "ody", "coalesce"],
...         ],
...     }
... )
>>> df.select(pl.col("values").str.extract_many("patterns"))
shape: (2, 1)
┌─────────────────┐
│ values          │
│ ---             │
│ list[str]       │
╞═════════════════╡
│ ["disco"]       │
│ ["rhap", "ody"] │
└─────────────────┘