Test ambiguous

crates/polars-time/src/replace.rs

@@ -158,7 +158,7 @@ impl PolarsReplaceDatetime for DatetimeChunked {
             microsecond,
             ambiguous,
             &self.time_unit(),
-            None,
+            self.time_zone().as_deref(),
             self.name(),
         )?;
 

py-polars/tests/unit/operations/namespaces/temporal/test_datetime.py

@@ -770,6 +770,47 @@ def test_replace_int() -> None:
     assert_frame_equal(result, expected)
 
 
+def test_replace_ambiguous() -> None:
+    # Value to be replaced by an ambiguous hour.
+    value = pl.select(
+        pl.datetime(2020, 10, 25, 5, time_zone="Europe/London")
+    ).to_series()
+
+    input = [2020, 10, 25, 1]
+    tz = "Europe/London"
+
+    # earliest
+    expected = pl.select(
+        pl.datetime(*input, time_zone=tz, ambiguous="earliest")
+    ).to_series()
+    result = value.dt.replace(hour=1, ambiguous="earliest")
+    assert_series_equal(result, expected)
+
+    # latest
+    expected = pl.select(
+        pl.datetime(*input, time_zone=tz, ambiguous="latest")
+    ).to_series()
+    result = value.dt.replace(hour=1, ambiguous="latest")
+    assert_series_equal(result, expected)
+
+    # null
+    expected = pl.select(
+        pl.datetime(*input, time_zone=tz, ambiguous="null")
+    ).to_series()
+    result = value.dt.replace(hour=1, ambiguous="null")
+    assert_series_equal(result, expected)
+
+    # raise
+    with pytest.raises(
+        ComputeError,
+        match=(
+            "datetime '2020-10-25 01:00:00' is ambiguous in time zone 'Europe/London'. "
+            "Please use `ambiguous` to tell how it should be localized."
+        ),
+    ):
+        value.dt.replace(hour=1, ambiguous="raise")
+
+
 @pytest.mark.parametrize(
     ("tzinfo", "time_zone"),
     [(None, None), (ZoneInfo("Asia/Kathmandu"), "Asia/Kathmandu")],