fix and test boolean Series indexing

py-polars/polars/eager/series.py

@@ -475,8 +475,18 @@ def __neg__(self) -> "Series":
 
     def __getitem__(self, item: Any) -> Any:
         if isinstance(item, int):
-            if item >= self.len():
-                raise IndexError
+            if item < 0:
+                item = self.len() + item
+            if self.dtype in (List, Date32, Date64, Object):
+                f = get_ffi_func("get_<>", self.dtype, self._s)
+                if f is None:
+                    return NotImplemented
+                out = f(item)
+                if self.dtype == List:
+                    return wrap_s(out)
+                return out
+
+            return self._s.get_idx(item)
         # assume it is boolean mask
         if isinstance(item, Series):
             return Series._from_pyseries(self._s.filter(item._s))

py-polars/src/series.rs

@@ -239,6 +239,10 @@ impl PySeries {
         }
     }
 
+    pub fn get_idx(&self, py: Python, idx: usize) -> PyObject {
+        Wrap(self.series.get(idx)).into_py(py)
+    }
+
     pub fn bitand(&self, other: &PySeries) -> PyResult<Self> {
         let out = self.series.bitand(&other.series).map_err(PyPolarsEr::from)?;
         Ok(out.into())

py-polars/tests/test_series.py

@@ -195,6 +195,21 @@ def test_rechunk():
     assert a.n_chunks() == 1
 
 
+def test_indexing():
+    a = pl.Series("a", [1, 2, None])
+    assert a[1] == 2
+    assert a[2] == None
+    b = pl.Series("b", [True, False])
+    assert b[0]
+    assert not b[1]
+    a = pl.Series("a", ["a", None])
+    assert a[0] == "a"
+    assert a[1] == None
+    a = pl.Series("a", [0.1, None])
+    assert a[0] == 0.1
+    assert a[1] == None
+
+
 def test_arrow():
     a = pl.Series("a", [1, 2, 3, None])
     out = a.to_arrow()