polars.Series.extend#

Series.extend(other: Series) → Self[source]#

Extend the memory backed by this Series with the values from another.

Different from append, which adds the chunks from other to the chunks of this series, extend appends the data from other to the underlying memory locations and thus may cause a reallocation (which is expensive).

If this does not cause a reallocation, the resulting data structure will not have any extra chunks and thus will yield faster queries.

Prefer extend over append when you want to do a query after a single append. For instance, during online operations where you add n rows and rerun a query.

Prefer append over extend when you want to append many times before doing a query. For instance, when you read in multiple files and want to store them in a single Series. In the latter case, finish the sequence of append operations with a rechunk.

Parameters:
other

Series to extend the series with.

Warning

This method modifies the series in-place. The series is returned for convenience only.

See also

append

Examples

>>> a = pl.Series("a", [1, 2, 3])
>>> b = pl.Series("b", [4, 5])
>>> a.extend(b)
shape: (5,)
Series: 'a' [i64]
[
    1
    2
    3
    4
    5
]

The resulting series will consist of a single chunk.

>>> a.n_chunks()
1