ultralytics 8.0.81 single-line docstring updates (#2061)

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

ultralytics/yolo/v8/detect/predict.py

@@ -10,12 +10,14 @@ from ultralytics.yolo.utils import DEFAULT_CFG, ROOT, ops
 class DetectionPredictor(BasePredictor):
 
     def preprocess(self, img):
+        """Convert an image to PyTorch tensor and normalize pixel values."""
         img = (img if isinstance(img, torch.Tensor) else torch.from_numpy(img)).to(self.model.device)
         img = img.half() if self.model.fp16 else img.float()  # uint8 to fp16/32
         img /= 255  # 0 - 255 to 0.0 - 1.0
         return img
 
     def postprocess(self, preds, img, orig_imgs):
+        """Postprocesses predictions and returns a list of Results objects."""
         preds = ops.non_max_suppression(preds,
                                         self.args.conf,
                                         self.args.iou,
@@ -35,6 +37,7 @@ class DetectionPredictor(BasePredictor):
 
 
 def predict(cfg=DEFAULT_CFG, use_python=False):
+    """Runs YOLO model inference on input image(s)."""
     model = cfg.model or 'yolov8n.pt'
     source = cfg.source if cfg.source is not None else ROOT / 'assets' if (ROOT / 'assets').exists() \
         else 'https://ultralytics.com/images/bus.jpg'