feat: Add unique operations for Decimal dtype (#20855)

pola-rs · Jan 23, 2025 · e4dcec5 · e4dcec5
1 parent 24fccc4
commit e4dcec5
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diff --git a/crates/polars-core/src/series/implementations/decimal.rs b/crates/polars-core/src/series/implementations/decimal.rs
@@ -336,6 +336,21 @@ impl SeriesTrait for SeriesWrap<DecimalChunked> {
         self.0.has_nulls()
     }
 
+    #[cfg(feature = "algorithm_group_by")]
+    fn unique(&self) -> PolarsResult<Series> {
+        Ok(self.apply_physical_to_s(|ca| ca.unique().unwrap()))
+    }
+
+    #[cfg(feature = "algorithm_group_by")]
+    fn n_unique(&self) -> PolarsResult<usize> {
+        self.0.n_unique()
+    }
+
+    #[cfg(feature = "algorithm_group_by")]
+    fn arg_unique(&self) -> PolarsResult<IdxCa> {
+        self.0.arg_unique()
+    }
+
     fn is_null(&self) -> BooleanChunked {
         self.0.is_null()
     }

diff --git a/py-polars/tests/unit/datatypes/test_decimal.py b/py-polars/tests/unit/datatypes/test_decimal.py
@@ -651,3 +651,11 @@ def test_fill_null() -> None:
     assert s.fill_null(strategy="forward").to_list() == [D("1.2"), D("1.2"), D("1.4")]
     assert s.fill_null(strategy="backward").to_list() == [D("1.2"), D("1.4"), D("1.4")]
     assert s.fill_null(strategy="mean").to_list() == [D("1.2"), D("1.3"), D("1.4")]
+
+
+def test_unique() -> None:
+    ser = pl.Series([D("1.1"), D("1.1"), D("2.2")])
+
+    assert ser.unique().to_list() == [D("1.1"), D("2.2")]
+    assert ser.n_unique() == 2
+    assert ser.arg_unique().to_list() == [0, 2]