🛠️ Merge pull request #192 from hardikdava/fix/coco_empty_fix

🛠️ Fixing empty detection coco dataset

Author: SkalskiP

supervision/dataset/utils.py

@@ -83,9 +83,11 @@ def map_detections_class_id(
         )
 
     detections_copy = copy.deepcopy(detections)
-    detections_copy.class_id = np.vectorize(source_to_target_mapping.get)(
-        detections_copy.class_id
-    )
+
+    if len(detections) > 0:
+        detections_copy.class_id = np.vectorize(source_to_target_mapping.get)(
+            detections_copy.class_id
+        )
 
     return detections_copy
 

test/dataset/test_utils.py

@@ -204,6 +204,12 @@ def test_build_class_index_mapping(
             mock_detections(xyxy=[[0, 0, 10, 10]], class_id=[1]),
             DoesNotRaise()
         ),  # single mapping
+        (
+                {0: 1, 1: 2},
+                Detections.empty(),
+                Detections.empty(),
+                DoesNotRaise()
+        ),  # empty detections
         (
             {0: 1, 1: 2},
             mock_detections(xyxy=[[0, 0, 10, 10]], class_id=[0]),