What would be the most idiomatic (and efficient) way to add a column in front of a polars data frame? Same thing like .with_column but add it at index 0?
>Solution :
You can select in the order you want your new DataFrame.
df = pl.DataFrame({
"a": [1, 2, 3],
"b": [True, None, False]
})
df.select([
pl.lit("foo").alias("z"),
pl.all()
])
shape: (3, 3)
┌─────┬─────┬───────┐
│ z ┆ a ┆ b │
│ --- ┆ --- ┆ --- │
│ str ┆ i64 ┆ bool │
╞═════╪═════╪═══════╡
│ foo ┆ 1 ┆ true │
├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌┤
│ foo ┆ 2 ┆ null │
├╌╌╌╌╌┼╌╌╌╌╌┼╌╌╌╌╌╌╌┤
│ foo ┆ 3 ┆ false │
└─────┴─────┴───────┘