Subprocess improvements (#10973)

* Use list-form arguments for subprocess.run calls where possible

Augments #10944

* Deduplicate curl code

* Avoid eval() to parse integer

---------

Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

classify/train.py

@@ -78,7 +78,7 @@ def train(opt, device):
             LOGGER.info(f'\nDataset not found ⚠️, missing path {data_dir}, attempting download...')
             t = time.time()
             if str(data) == 'imagenet':
-                subprocess.run(f"bash {ROOT / 'data/scripts/get_imagenet.sh'}", shell=True, check=True)
+                subprocess.run(["bash", str(ROOT / 'data/scripts/get_imagenet.sh')], shell=True, check=True)
             else:
                 url = f'https://github.com/ultralytics/yolov5/releases/download/v1.0/{data}.zip'
                 download(url, dir=data_dir.parent)