dataframepython-polars

How to select columns by data type in Polars?

In pandas we have the pandas.DataFrame.select_dtypes method that selects certain columns depending on the dtype. Is there a similar way to do such a thing in Polars?

Solution

  • One can pass data type(s) to pl.col:

    import polars as pl

df = pl.DataFrame(
    {
        "id": [1, 2, 3],
        "name": ["John", "Jane", "Jake"],
        "else": [10.0, 20.0, 30.0],
    }
)
print(df.select(pl.col(pl.String, pl.Int64)))

    Output:

    shape: (3, 2)
┌─────┬──────┐
│ id  ┆ name │
│ --- ┆ ---  │
│ i64 ┆ str  │
╞═════╪══════╡
│ 1   ┆ John │
│ 2   ┆ Jane │
│ 3   ┆ Jake │
└─────┴──────┘