I have a Polars dataframe pydf in Python with a datetime column time1 that I’m passing to Rust.
In Rust I am calling code that works with epoch format, but afterwards it should return another dataframe with a datetime column time2_epoch in the same time unit and time zone as time1.

Currently I perform the conversion to and from epoch on the Python side.

from datetime import datetime
from zoneinfo import ZoneInfo
import polars as pl

pydf = pl.DataFrame({'time1': datetime(2024, 1, 1, tzinfo=ZoneInfo("UTC"))})

time_zone = pydf.schema['time1'].time_zone
time_unit = pydf.schema['time1'].time_unit

pydf_epoch = pydf.with_columns(pl.col('time1').dt.epoch(time_unit))

On the Rust side I have this function accepting the Polars dataframe and the time unit

fn foo(pydf: PyDataFrame, time_unit: &str) -> PyResult<PyDataFrame> {
    // Work on pydf and return a dataframe with column time2_epoch whose precision is time_unit
}

Back on the Python side I convert time2_epoch to a datetime column

rustdf.with_columns(
    pl.from_epoch(pl.col('time2_epoch'), time_unit).alias('time2')
).with_columns(
    pl.col('time2').dt.convert_time_zone(time_zone)
)

Is it possible to pass pydf directly to foo and perform the time conversions in Rust?

I can get the type of the time1 column (an enum AFAIK), but I don’t know how to extract the time zone and time unit from this

let schema = pydf.schema();
let time1_type = schema.get("time1").unwrap();