Support for arrays.

crates/polars-core/src/chunked_array/ops/search.rs

@@ -29,3 +29,15 @@ impl ChunkSearch<'_, &Series> for ListChunked {
             })
     }
 }
+
+#[cfg(feature="dtype-array")]
+impl ChunkSearch<'_, &Series> for ArrayChunked {
+    fn index_of(&self, value: Option<&Series>) -> Option<usize> {
+        self.amortized_iter()
+            .position(|opt_val| match (opt_val, value) {
+                (Some(in_series), Some(value)) => in_series.as_ref() == value,
+                (None, None) => true,
+                _ => false,
+            })
+    }
+}

crates/polars-python/src/series/scatter.rs

@@ -199,6 +199,15 @@ fn index_of(series: &Series, value_series: &Series) -> PolarsResult<Option<usize
                 .map(|arr| Series::from_arrow("".into(), arr).unwrap());
             Ok(series.list()?.index_of(value.as_ref()))
         },
+        #[cfg(feature="dtype-array")]
+        DataType::Array(_, _) => {
+            let value = value_series
+                .array()
+                .unwrap()
+                .get(0)
+                .map(|arr| Series::from_arrow("".into(), arr).unwrap());
+            Ok(series.array()?.index_of(value.as_ref()))
+        },
         _ => unimplemented!("TODO"),
     }
 }

py-polars/polars/series/series.py

@@ -4749,12 +4749,14 @@ def index_of(
         TODO
         """
         if isinstance(value, Series):
-            # Searching for lists...
-            # TODO what about searching for arrays?
+            # Searching for lists or arrays:
             value = value.implode()
         else:
             value = Series(values=[value])
 
+        if isinstance(self.dtype, Array):
+            value = value.cast(Array(self.dtype.inner, len(value[0])))
+
         return self._s.index_of(value._s)
 
     def clear(self, n: int = 0) -> Series: