How do you vertically concatenate two Polars data frames in Rust?

Question

According to the Polars documentation, in Python, you can vertically concatenate two data frames using the procedure shown in the below code snippet:

df_v1 = pl.DataFrame(
    {
        "a": [1],
        "b": [3],
    }
)
df_v2 = pl.DataFrame(
    {
        "a": [2],
        "b": [4],
    }
)
df_vertical_concat = pl.concat(
    [
        df_v1,
        df_v2,
    ],
    how="vertical",
)
print(df_vertical_concat)

The output of the above code is:

shape: (2, 2)
┌─────┬─────┐
│ a   ┆ b   │
│ --- ┆ --- │
│ i64 ┆ i64 │
╞═════╪═════╡
│ 1   ┆ 3   │
├╌╌╌╌╌┼╌╌╌╌╌┤
│ 2   ┆ 4   │
└─────┴─────┘

How do you perform the same operation in Rust?

score 2 · Answer 1 · answered Sep 07 '22 at 12:53

2

You can do it as follows:

let df_vertical_concat = df_v1.vstack(&df_v2).unwrap();

answered Sep 07 '22 at 12:53

Darnock

69
3

3

If using the Lazy API, it becomes [`concat(&[my, lazy, frames], should_rechunk)?`](https://docs.rs/polars/latest/polars/prelude/fn.concat.html) – BallpointBen Sep 07 '22 at 17:42
And now `concat()` has a third argument, `parallel: bool` – BallpointBen Mar 03 '23 at 18:51

How do you vertically concatenate two Polars data frames in Rust?

1 Answers1