polars_python/conversion/
datetime.rs

1//! Utilities for converting dates, times, datetimes, and so on.
2
3use std::str::FromStr;
4
5use chrono::{DateTime, Datelike, FixedOffset, NaiveDateTime, NaiveTime, TimeDelta, TimeZone as _};
6use chrono_tz::Tz;
7use polars::datatypes::TimeUnit;
8use polars_core::datatypes::TimeZone;
9use pyo3::types::PyAnyMethods;
10use pyo3::{Bound, IntoPyObjectExt, PyAny, PyResult, Python, intern};
11
12use crate::error::PyPolarsErr;
13use crate::py_modules::pl_utils;
14
15pub fn elapsed_offset_to_timedelta(elapsed: i64, time_unit: TimeUnit) -> TimeDelta {
16    let (in_second, nano_multiplier) = match time_unit {
17        TimeUnit::Nanoseconds => (1_000_000_000, 1),
18        TimeUnit::Microseconds => (1_000_000, 1_000),
19        TimeUnit::Milliseconds => (1_000, 1_000_000),
20    };
21    let mut elapsed_sec = elapsed / in_second;
22    let mut elapsed_nanos = nano_multiplier * (elapsed % in_second);
23    if elapsed_nanos < 0 {
24        // TimeDelta expects nanos to always be positive.
25        elapsed_sec -= 1;
26        elapsed_nanos += 1_000_000_000;
27    }
28    TimeDelta::new(elapsed_sec, elapsed_nanos as u32).unwrap()
29}
30
31/// Convert time-units-since-epoch to a more structured object.
32pub fn timestamp_to_naive_datetime(since_epoch: i64, time_unit: TimeUnit) -> NaiveDateTime {
33    DateTime::UNIX_EPOCH.naive_utc() + elapsed_offset_to_timedelta(since_epoch, time_unit)
34}
35
36/// Convert nanoseconds-since-midnight to a more structured object.
37pub fn nanos_since_midnight_to_naivetime(nanos_since_midnight: i64) -> NaiveTime {
38    NaiveTime::from_hms_opt(0, 0, 0).unwrap()
39        + elapsed_offset_to_timedelta(nanos_since_midnight, TimeUnit::Nanoseconds)
40}
41
42pub fn datetime_to_py_object<'py>(
43    py: Python<'py>,
44    v: i64,
45    tu: TimeUnit,
46    tz: Option<&TimeZone>,
47) -> PyResult<Bound<'py, PyAny>> {
48    if let Some(time_zone) = tz {
49        if let Ok(tz) = Tz::from_str(time_zone) {
50            let utc_datetime = DateTime::UNIX_EPOCH + elapsed_offset_to_timedelta(v, tu);
51            if utc_datetime.year() >= 2100 {
52                // chrono-tz does not support dates after 2100
53                // https://github.com/chronotope/chrono-tz/issues/135
54                pl_utils(py)
55                    .bind(py)
56                    .getattr(intern!(py, "to_py_datetime"))?
57                    .call1((v, tu.to_ascii(), time_zone.as_str()))
58            } else {
59                let datetime = utc_datetime.with_timezone(&tz);
60                datetime.into_bound_py_any(py)
61            }
62        } else if let Ok(tz) = FixedOffset::from_str(time_zone) {
63            let naive_datetime = timestamp_to_naive_datetime(v, tu);
64            let datetime = tz.from_utc_datetime(&naive_datetime);
65            datetime.into_bound_py_any(py)
66        } else {
67            Err(PyPolarsErr::Other(format!("Could not parse timezone: {time_zone}")).into())
68        }
69    } else {
70        timestamp_to_naive_datetime(v, tu).into_bound_py_any(py)
71    }
72}
polars_python/conversion/datetime.rs

polars_python/conversion/
datetime.rs
