[Python] How to do a horizontal forward_fill in Polars?

I am wondering if there's a way to do forward filling by columns in polars.

df = pl.DataFrame(
{
"id": ["NY", "TK", "FD"],
"eat2000": [1, 6, 3],
"eat2001": [-2, None, 4],
"eat2002": [None, None, None],
"eat2003": [-9, 3, 8],
"eat2004": [None, None, 8]
}
); df


shape: (3, 6)
┌─────┬─────────┬─────────┬─────────┬─────────┬─────────┐
│ id ┆ eat2000 ┆ eat2001 ┆ eat2002 ┆ eat2003 ┆ eat2004 │
│ --- ┆ --- ┆ --- ┆ --- ┆ --- ┆ --- │
│ str ┆ i64 ┆ i64 ┆ f64 ┆ i64 ┆ i64 │
╞═════╪═════════╪═════════╪═════════╪═════════╪═════════╡
│ NY ┆ 1 ┆ -2 ┆ null ┆ -9 ┆ null │
│ TK ┆ 6 ┆ null ┆ null ┆ 3 ┆ null │
│ FD ┆ 3 ┆ 4 ┆ null ┆ 8 ┆ 8 │
└─────┴─────────┴─────────┴─────────┴─────────┴─────────┘


I would like to do the equivlanet of .ffill(axis=1) in pandas.

pl.from_pandas(df.to_pandas().ffill(axis=1))


shape: (3, 6)
┌─────┬─────────┬─────────┬─────────┬─────────┬─────────┐
│ id ┆ eat2000 ┆ eat2001 ┆ eat2002 ┆ eat2003 ┆ eat2004 │
│ --- ┆ --- ┆ --- ┆ --- ┆ --- ┆ --- │
│ str ┆ i64 ┆ f64 ┆ f64 ┆ i64 ┆ f64 │
╞═════╪═════════╪═════════╪═════════╪═════════╪═════════╡
│ NY ┆ 1 ┆ -2.0 ┆ -2.0 ┆ -9 ┆ -9.0 │
│ TK ┆ 6 ┆ 6.0 ┆ 6.0 ┆ 3 ┆ 3.0 │
│ FD ┆ 3 ┆ 4.0 ┆ 4.0 ┆ 8 ┆ 8.0 │
└─────┴─────────┴─────────┴─────────┴─────────┴─────────┘

Continue reading...