polars.Series.arr.shift#

Series.arr.shift(n: int | IntoExprColumn = 1) → Series[source]#

Shift array values by the given number of indices.

Parameters:

n: Number of indices to shift forward. If a negative value is passed, values are shifted in the opposite direction instead.

Notes

This method is similar to the LAG operation in SQL when the value for n is positive. With a negative value for n, it is similar to LEAD.

Examples

By default, array values are shifted forward by one index.

>>> s = pl.Series([[1, 2, 3], [4, 5, 6]], dtype=pl.Array(pl.Int64, 3))
>>> s.arr.shift()
shape: (2,)
Series: '' [array[i64, 3]]
[
    [null, 1, 2]
    [null, 4, 5]
]

Pass a negative value to shift in the opposite direction instead.

>>> s.arr.shift(-2)
shape: (2,)
Series: '' [array[i64, 3]]
[
    [3, null, null]
    [6, null, null]
]