Omit ultralytics/utils/callbacks from coverage (#4345)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

ultralytics/models/fastsam/model.py

@@ -12,16 +12,18 @@ class FastSAM(Model):
     """
     FastSAM model interface.
 
-    Usage - Predict:
+    Example:
+        ```python
         from ultralytics import FastSAM
 
         model = FastSAM('last.pt')
         results = model.predict('ultralytics/assets/bus.jpg')
+        ```
     """
 
     def __init__(self, model='FastSAM-x.pt'):
         """Call the __init__ method of the parent class (YOLO) with the updated default model"""
-        if model == 'FastSAM.pt':
+        if str(model) == 'FastSAM.pt':
             model = 'FastSAM-x.pt'
         assert Path(model).suffix not in ('.yaml', '.yml'), 'FastSAM models only support pre-trained models.'
         super().__init__(model=model, task='segment')

ultralytics/models/nas/model.py

@@ -2,11 +2,13 @@
 """
 YOLO-NAS model interface.
 
-Usage - Predict:
+Example:
+    ```python
     from ultralytics import NAS
 
     model = NAS('yolo_nas_s')
     results = model.predict('ultralytics/assets/bus.jpg')
+    ```
 """
 
 from pathlib import Path

ultralytics/models/sam/model.py

@@ -3,6 +3,8 @@
 SAM model interface
 """
 
+from pathlib import Path
+
 from ultralytics.engine.model import Model
 from ultralytics.utils.torch_utils import model_info
 
@@ -16,9 +18,8 @@ class SAM(Model):
     """
 
     def __init__(self, model='sam_b.pt') -> None:
-        if model and not model.endswith('.pt') and not model.endswith('.pth'):
-            # Should raise AssertionError instead?
-            raise NotImplementedError('Segment anything prediction requires pre-trained checkpoint')
+        if model and Path(model).suffix not in ('.pt', '.pth'):
+            raise NotImplementedError('SAM prediction requires pre-trained *.pt or *.pth model.')
         super().__init__(model=model, task='segment')
 
     def _load(self, weights: str, task=None):