Remove FrameGroup._frame_idx_registry class attribute

sleap/io/cameras.py

@@ -1317,10 +1317,6 @@ class FrameGroup:
     )  # Akin to `LabeledFrame.instances`
     _instance_group_name_registry: Set[str] = field(factory=set)
 
-    # TODO(LM): Should we move this to an instance attribute of `RecordingSession`?
-    # Class attribute to keep track of frame indices across all `RecordingSession`s
-    _frame_idx_registry: Dict[RecordingSession, Set[int]] = {}
-
     # "Hidden" class attribute
     _cams_to_include: Optional[List[Camcorder]] = None
     _excluded_views: Optional[Tuple[str]] = ()
@@ -1354,12 +1350,6 @@ def __attrs_post_init__(self):
         if self._cams_to_include is not None:
             self.cams_to_include = self._cams_to_include
 
-        # Add frame index to registry
-        if self.session not in self._frame_idx_registry:
-            self._frame_idx_registry[self.session] = set()
-
-        self._frame_idx_registry[self.session].add(self.frame_idx)
-
         # Add `FrameGroup` to `RecordingSession`
         self.session._frame_group_by_frame_idx[self.frame_idx] = self
 
@@ -2016,11 +2006,11 @@ def enforce_frame_idx_unique(
             frame_idx: Frame index.
         """
 
-        if frame_idx in self._frame_idx_registry.get(session, set()):
+        if session.frame_groups.get(frame_idx, None) is not None:
             # Remove existing `FrameGroup` object from the
             # `RecordingSession._frame_group_by_frame_idx`
             logger.warning(
                 f"Frame index {frame_idx} for FrameGroup already exists in this "
                 "RecordingSession. Overwriting."
             )
-            session._frame_group_by_frame_idx.pop(frame_idx)
+            session.frame_groups.pop(frame_idx)

tests/io/test_cameras.py

@@ -440,34 +440,30 @@ def test_frame_group(multiview_min_session_labels: Labels):
         session=session, instance_groups=instance_groups
     )
     assert isinstance(frame_group_1, FrameGroup)
-    assert session in frame_group_1._frame_idx_registry
-    assert len(frame_group_1._frame_idx_registry) == 1
-    assert frame_group_1._frame_idx_registry[session] == {frame_idx_1}
+    assert frame_idx_1 in session.frame_groups
+    assert len(session.frame_groups) == 1
+    assert frame_group_1 == session.frame_groups[frame_idx_1]
+    assert len(frame_group_1.instance_groups) == 1
 
-    # Test `_frame_idx_registry` property
+    # Test `RecordingSession.frame_groups` property
     frame_idx_2 = 1
     instance_group = create_instance_group(labels=labels, frame_idx=frame_idx_2)
     instance_groups: List[InstanceGroup] = [instance_group]
     frame_group_2 = FrameGroup.from_instance_groups(
         session=session, instance_groups=instance_groups
     )
     assert isinstance(frame_group_2, FrameGroup)
-    assert session in frame_group_2._frame_idx_registry
-    assert len(frame_group_2._frame_idx_registry) == 1
-    assert frame_group_2._frame_idx_registry[session] == {frame_idx_1, frame_idx_2}
-    assert frame_group_1._frame_idx_registry == frame_group_2._frame_idx_registry
+    assert frame_idx_2 in session.frame_groups
+    assert len(session.frame_groups) == 2
+    assert frame_group_2 == session.frame_groups[frame_idx_2]
+    assert len(frame_group_2.instance_groups) == 1
 
     frame_idx_3 = 2
     frame_group_3 = FrameGroup(frame_idx=frame_idx_3, session=session)
     assert isinstance(frame_group_3, FrameGroup)
-    assert session in frame_group_3._frame_idx_registry
-    assert len(frame_group_3._frame_idx_registry) == 1
-    assert frame_group_3._frame_idx_registry[session] == {
-        frame_idx_1,
-        frame_idx_2,
-        frame_idx_3,
-    }
-    assert frame_group_1._frame_idx_registry == frame_group_3._frame_idx_registry
+    assert frame_idx_3 in session.frame_groups
+    assert len(session.frame_groups) == 3
+    assert frame_group_3 == session.frame_groups[frame_idx_3]
     assert len(frame_group_3.instance_groups) == 0
 
     # TODO(LM): Test underlying dictionaries more thoroughly