Pycocotools best.pt after COCO train (#1616)

* Pycocotools best.pt after COCO train

* cleanup

utils/google_utils.py

@@ -17,7 +17,7 @@ def gsutil_getsize(url=''):
 
 def attempt_download(weights):
     # Attempt to download pretrained weights if not found locally
-    weights = weights.strip().replace("'", '')
+    weights = str(weights).strip().replace("'", '')
     file = Path(weights).name.lower()
 
     msg = weights + ' missing, try downloading from https://github.com/ultralytics/yolov5/releases/'