polars.Series.str.extract_groups#

Series.str.extract_groups(pattern: str) → Series[source]#

Extract all capture groups for the given regex pattern.

Parameters:

pattern: A valid regular expression pattern containing at least one capture group, compatible with the regex crate.

Returns:

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

Notes

All group names are strings.

If your pattern contains unnamed groups, their numerical position is converted to a string.

For example, we can access the first group via the string "1":

>>> (
...     pl.Series(["foo bar baz"])
...     .str.extract_groups(r"(\w+) (.+) (\w+)")
...     .struct["1"]
... )
shape: (1,)
Series: '1' [str]
[
    "foo"
]

Examples

>>> s = pl.Series(
...     name="url",
...     values=[
...         "http://vote.com/ballon_dor?candidate=messi&ref=python",
...         "http://vote.com/ballon_dor?candidate=weghorst&ref=polars",
...         "http://vote.com/ballon_dor?error=404&ref=rust",
...     ],
... )
>>> s.str.extract_groups(r"candidate=(?<candidate>\w+)&ref=(?<ref>\w+)")
shape: (3,)
Series: 'url' [struct[2]]
[
    {"messi","python"}
    {"weghorst","polars"}
    {null,null}
]