python better datetime.time support (#3243)

polars/polars-core/src/series/from.rs

@@ -154,6 +154,10 @@ impl Series {
             }
             #[cfg(feature = "dtype-time")]
             ArrowDataType::Time64(tu) | ArrowDataType::Time32(tu) => {
+                let mut chunks = chunks;
+                if matches!(dtype, ArrowDataType::Time32(_)) {
+                    chunks = cast_chunks(&chunks, &DataType::Int32).unwrap();
+                }
                 let chunks = cast_chunks(&chunks, &DataType::Int64).unwrap();
                 let s = Int64Chunked::from_chunks(name, chunks)
                     .into_time()

py-polars/polars/utils.py

@@ -1,7 +1,7 @@
 import ctypes
 import os
 import sys
-from datetime import date, datetime, timedelta, timezone
+from datetime import date, datetime, time, timedelta, timezone
 from pathlib import Path
 from typing import Any, Dict, Iterable, List, Optional, Sequence, Tuple, Type, Union
 
@@ -142,6 +142,18 @@ def handle_projection_columns(
     return projection, columns  # type: ignore
 
 
+def _to_python_time(value: int) -> time:
+    value = value // 1_000
+    microsecond = value
+    seconds = (microsecond // 1000_000) % 60
+    minutes = (microsecond // (1000_000 * 60)) % 60
+    hours = (microsecond // (1000_000 * 60 * 60)) % 24
+
+    microsecond = microsecond % seconds * 1000_000
+
+    return time(hour=hours, minute=minutes, second=seconds, microsecond=microsecond)
+
+
 def _to_python_timedelta(
     value: Union[int, float], tu: Optional[str] = "ns"
 ) -> timedelta:

py-polars/src/conversion.rs

@@ -452,6 +452,19 @@ impl ToPyObject for Wrap<&DatetimeChunked> {
     }
 }
 
+impl ToPyObject for Wrap<&TimeChunked> {
+    fn to_object(&self, py: Python) -> PyObject {
+        let pl = PyModule::import(py, "polars").unwrap();
+        let pl_utils = pl.getattr("utils").unwrap();
+        let convert = pl_utils.getattr("_to_python_time").unwrap();
+        let iter = self
+            .0
+            .into_iter()
+            .map(|opt_v| opt_v.map(|v| convert.call1((v,)).unwrap()));
+        PyList::new(py, iter).into_py(py)
+    }
+}
+
 impl ToPyObject for Wrap<&DateChunked> {
     fn to_object(&self, py: Python) -> PyObject {
         let pl = PyModule::import(py, "polars").unwrap();

py-polars/src/series.rs

@@ -719,6 +719,10 @@ impl PySeries {
                     let ca = series.date().unwrap();
                     return Wrap(ca).to_object(python);
                 }
+                DataType::Time => {
+                    let ca = series.time().unwrap();
+                    return Wrap(ca).to_object(python);
+                }
                 DataType::Datetime(_, _) => {
                     let ca = series.datetime().unwrap();
                     return Wrap(ca).to_object(python);

py-polars/tests/test_datelike.py

@@ -1,5 +1,6 @@
 import io
-from datetime import date, datetime, timedelta
+import typing
+from datetime import date, datetime, time, timedelta
 
 import numpy as np
 import pandas as pd
@@ -834,3 +835,15 @@ def test_agg_logical() -> None:
     s = pl.Series(dates)
     assert s.max() == dates[1]
     assert s.min() == dates[0]
+
+
+@typing.no_type_check
+def test_from_time_arrow() -> None:
+    times = pa.array([10, 20, 30], type=pa.time32("s"))
+    times_table = pa.table([times], names=["times"])
+
+    assert pl.from_arrow(times_table).to_series().to_list() == [
+        time(0, 0, 10),
+        time(0, 0, 20),
+        time(0, 0, 30),
+    ]