ultralytics 8.0.21 Windows, segments, YAML fixes (#655)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: corey-nm <109536191+corey-nm@users.noreply.github.com>

ultralytics/yolo/data/dataloaders/stream_loaders.py

@@ -44,7 +44,8 @@ class LoadStreams:
                 assert not is_colab(), '--source 0 webcam unsupported on Colab. Rerun command in a local environment.'
                 assert not is_kaggle(), '--source 0 webcam unsupported on Kaggle. Rerun command in a local environment.'
             cap = cv2.VideoCapture(s)
-            assert cap.isOpened(), f'{st}Failed to open {s}'
+            if not cap.isOpened():
+                raise ConnectionError(f'{st}Failed to open {s}')
             w = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
             h = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
             fps = cap.get(cv2.CAP_PROP_FPS)  # warning: may return 0 or nan
@@ -188,8 +189,9 @@ class LoadImages:
             self._new_video(videos[0])  # new video
         else:
             self.cap = None
-        assert self.nf > 0, f'No images or videos found in {p}. ' \
-                            f'Supported formats are:\nimages: {IMG_FORMATS}\nvideos: {VID_FORMATS}'
+        if self.nf == 0:
+            raise FileNotFoundError(f'No images or videos found in {p}. '
+                                    f'Supported formats are:\nimages: {IMG_FORMATS}\nvideos: {VID_FORMATS}')
 
     def __iter__(self):
         self.count = 0
@@ -223,7 +225,8 @@ class LoadImages:
             # Read image
             self.count += 1
             im0 = cv2.imread(path)  # BGR
-            assert im0 is not None, f'Image Not Found {path}'
+            if im0 is None:
+                raise FileNotFoundError(f'Image Not Found {path}')
             s = f'image {self.count}/{self.nf} {path}: '
 
         if self.transforms:

ultralytics/yolo/data/dataloaders/v5loader.py

@@ -23,14 +23,13 @@ import numpy as np
 import psutil
 import torch
 import torchvision
-import yaml
 from PIL import ExifTags, Image, ImageOps
 from torch.utils.data import DataLoader, Dataset, dataloader, distributed
 from tqdm import tqdm
 
 from ultralytics.yolo.data.utils import check_det_dataset, unzip_file
 from ultralytics.yolo.utils import (DATASETS_DIR, LOGGER, NUM_THREADS, TQDM_BAR_FORMAT, is_colab, is_dir_writeable,
-                                    is_kaggle)
+                                    is_kaggle, yaml_load)
 from ultralytics.yolo.utils.checks import check_requirements, check_yaml
 from ultralytics.yolo.utils.ops import clean_str, segments2boxes, xyn2xy, xywh2xyxy, xywhn2xyxy, xyxy2xywhn
 from ultralytics.yolo.utils.torch_utils import torch_distributed_zero_first
@@ -1056,10 +1055,9 @@ class HUBDatasetStats():
         # Initialize class
         zipped, data_dir, yaml_path = self._unzip(Path(path))
         try:
-            with open(check_yaml(yaml_path), errors='ignore') as f:
-                data = yaml.safe_load(f)  # data dict
-                if zipped:
-                    data['path'] = data_dir
+            data = yaml_load(check_yaml(yaml_path))  # data dict
+            if zipped:
+                data['path'] = data_dir
         except Exception as e:
             raise Exception("error/HUB/dataset_stats/yaml_load") from e