allow summing of duration in selection context (#4124)

pola-rs · Jul 22, 2022 · bd0d4a6 · bd0d4a6
1 parent bb45843
commit bd0d4a6
Show file tree

Hide file tree

Showing 2 changed files with 19 additions and 3 deletions.
diff --git a/polars/polars-core/src/series/implementations/duration.rs b/polars/polars-core/src/series/implementations/duration.rs
@@ -496,10 +496,9 @@ impl SeriesTrait for SeriesWrap<DurationChunked> {
     }
 
     fn _sum_as_series(&self) -> Series {
-        Int32Chunked::full_null(self.name(), 1)
-            .cast(self.dtype())
-            .unwrap()
+        self.0.sum_as_series().into_duration(self.0.time_unit())
     }
+
     fn max_as_series(&self) -> Series {
         self.0.max_as_series().into_duration(self.0.time_unit())
     }

diff --git a/py-polars/tests/test_datelike.py b/py-polars/tests/test_datelike.py
@@ -1223,3 +1223,20 @@ def test_time_microseconds_3843() -> None:
 def test_year_empty_df() -> None:
     df = pl.DataFrame(pl.Series(name="date", dtype=pl.Date))
     assert df.select(pl.col("date").dt.year()).dtypes == [pl.Int32]
+
+
+def test_sum_duration() -> None:
+    assert pl.DataFrame(
+        [
+            {"name": "Jen", "duration": timedelta(seconds=60)},
+            {"name": "Mike", "duration": timedelta(seconds=30)},
+            {"name": "Jen", "duration": timedelta(seconds=60)},
+        ]
+    ).select(
+        [pl.col("duration").sum(), pl.col("duration").dt.seconds().alias("sec").sum()]
+    ).to_dict(
+        False
+    ) == {
+        "duration": [timedelta(seconds=150)],
+        "sec": [150],
+    }