polars.Series.is_between

Series.is_between(
    lower_bound: IntoExpr,
    upper_bound: IntoExpr,
    closed: ClosedInterval = 'both',
) → Series

Get a boolean mask of the values that are between the given lower/upper bounds.

Parameters:

lower_bound

Lower bound value. Accepts expression input. Non-expression inputs (including strings) are parsed as literals.

upper_bound

Upper bound value. Accepts expression input. Non-expression inputs (including strings) are parsed as literals.

closed{‘both’, ‘left’, ‘right’, ‘none’}

Define which sides of the interval are closed (inclusive).

Notes

If the value of the lower_bound is greater than that of the upper_bound then the result will be False, as no value can satisfy the condition.

Examples

>>> s = pl.Series("num", [1, 2, 3, 4, 5])
>>> s.is_between(2, 4)
shape: (5,)
Series: 'num' [bool]
[
    false
    true
    true
    true
    false
]

Use the closed argument to include or exclude the values at the bounds:

>>> s.is_between(2, 4, closed="left")
shape: (5,)
Series: 'num' [bool]
[
    false
    true
    true
    false
    false
]

You can also use strings as well as numeric/temporal values:

>>> s = pl.Series("s", ["a", "b", "c", "d", "e"])
>>> s.is_between("b", "d", closed="both")
shape: (5,)
Series: 's' [bool]
[
    false
    true
    true
    true
    false
]