polars.Series.str.contains#

Series.str.contains( pattern: str | Expr, *, literal: bool = False, strict: bool = True, ) → Series[source]#

Check if strings in Series contain a substring that matches a regex.

Parameters:

pattern: A valid regular expression pattern, compatible with the regex crate.
literal: Treat pattern as a literal string, not as a regular expression.
strict: Raise an error if the underlying pattern is not a valid regex, otherwise mask out with a null value.

Returns:

Series: Series of data type Boolean.

Notes

To modify regular expression behaviour (such as case-sensitivity) with flags, use the inline (?iLmsuxU) syntax. For example:

Default (case-sensitive) match:

>>> s = pl.Series("s", ["AAA", "aAa", "aaa"])
>>> s.str.contains("AA").to_list()
[True, False, False]

Case-insensitive match, using an inline flag:

>>> s = pl.Series("s", ["AAA", "aAa", "aaa"])
>>> s.str.contains("(?i)AA").to_list()
[True, True, True]

See the regex crate’s section on grouping and flags for additional information about the use of inline expression modifiers.

Examples

>>> s = pl.Series(["Crab", "cat and dog", "rab$bit", None])
>>> s.str.contains("cat|bit")
shape: (4,)
Series: '' [bool]
[
    false
    true
    true
    null
]
>>> s.str.contains("rab$", literal=True)
shape: (4,)
Series: '' [bool]
[
    false
    false
    true
    null
]