Add check_requirements(('pycocotools>=2.0',)) (ultralytics#7295)

Add  `check_requirements(('pycocotools>=2.0',))`

Author: glenn-jocher

data/Objects365.yaml

@@ -60,11 +60,12 @@ names: ['Person', 'Sneakers', 'Chair', 'Other Shoes', 'Hat', 'Car', 'Lamp', 'Gla
 
 # Download script/URL (optional) ---------------------------------------------------------------------------------------
 download: |
-  from pycocotools.coco import COCO
   from tqdm import tqdm
-
-  from utils.general import Path, download, np, xyxy2xywhn
-
+  
+  from utils.general import Path, check_requirements, download, np, xyxy2xywhn
+  
+  check_requirements(('pycocotools>=2.0',))
+  from pycocotools.coco import COCO
 
   # Make Directories
   dir = Path(yaml['path'])  # dataset root dir