W&B sweeps support (#3938)

* Add support for W&B Sweeps

* Update and reformat

* Update search space

* reformat

* reformat sweep.py

* Update sweep.py

* Move sweeps files to wandb dir

* Remove print

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

utils/wandb_logging/sweep.py

@@ -0,0 +1,33 @@
+import sys
+from pathlib import Path
+import wandb
+
+FILE = Path(__file__).absolute()
+sys.path.append(FILE.parents[2].as_posix())  # add utils/ to path
+
+from train import train, parse_opt
+import test
+from utils.general import increment_path
+from utils.torch_utils import select_device
+
+
+def sweep():
+    wandb.init()
+    # Get hyp dict from sweep agent
+    hyp_dict = vars(wandb.config).get("_items")
+
+    # Workaround: get necessary opt args
+    opt = parse_opt(known=True)
+    opt.batch_size = hyp_dict.get("batch_size")
+    opt.save_dir = str(increment_path(Path(opt.project) / opt.name, exist_ok=opt.exist_ok or opt.evolve))
+    opt.epochs = hyp_dict.get("epochs")
+    opt.nosave = True
+    opt.data = hyp_dict.get("data")
+    device = select_device(opt.device, batch_size=opt.batch_size)
+
+    # train
+    train(hyp_dict, opt, device)
+
+
+if __name__ == "__main__":
+    sweep()